mergetools: add new conflict marker format with diffs in

I use 3-way conflict markers. Often when I resolve them, I manually
compare one the base with one side and apply the differences to the
other side. That can be hard when the conflict marker is large. This
patch introduces a new type of conflict marker, which I'm hoping will
make it easier to resolve conflicts.

The new format uses `<<<<<<<` and `>>>>>>>` to open and close the
markers, just like our existing 2-way and 3-way conflict
markers. Instead of having 2 or 3 snapshots (left+right or
left+base+right), it has a sequence of diffs. A diff looks like this:

```
------- base
+++++++ left
 a
-b
+c
 d
```

A diff that adds one side ("diff from nothing") has a `=======` header
instead and does not have have `+` prefixed on its lines. A regular
3-way merge can be viewed as adding one side plus a diff between the
base and the other side. It thus has two ways of being represented,
depending on which side is being diffed:

```
<<<<<<<
======= left
contents
on
left
------- base
+++++++ right
 contents
 on
-left
+right
>>>>>>>
```
or
```
<<<<<<<
------- base
+++++++ left
 contents
 on
-right
+left
======= right
contents
on
right
>>>>>>>
```

I've made it so the new merge tool tries to pick a version that has
the most common lines (no difference in the example above).


I've called the new tool "mergediff" to stick to the convention of
starting with "merge" if the tool tries a regular 3-way merge.

The idea came from my pet VCS (placeholder name `jj`), which has
support for octopus merges and other ways of ending up with merges of
more than 3 versions. I wanted to be able to represent such conflicts
in the working copy and therefore thought of this format (although I
have not yet implemented it in my VCS). I then attended a meeting with
Larry McVoy, who said BitKeeper has an option (`bk smerge -g`) for
showing a similar format, which reminded me to actually attempt this
in Mercurial.

Differential Revision: https://phab.mercurial-scm.org/D9551

mercurial/filemerge.py

@@ -1,1266 +1,1293 b''
 # filemerge.py - file-level merge handling for Mercurial
 #
 # Copyright 2006, 2007, 2008 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import contextlib
 import os
 import re
 import shutil
 
 from .i18n import _
 from .node import (
     hex,
     nullid,
     short,
 )
 from .pycompat import (
     getattr,
     open,
 )
 
 from . import (
     encoding,
     error,
     formatter,
     match,
     pycompat,
     registrar,
     scmutil,
     simplemerge,
     tagmerge,
     templatekw,
     templater,
     templateutil,
     util,
 )
 
 from .utils import (
     procutil,
     stringutil,
 )
 
 
 def _toolstr(ui, tool, part, *args):
     return ui.config(b"merge-tools", tool + b"." + part, *args)
 
 
 def _toolbool(ui, tool, part, *args):
     return ui.configbool(b"merge-tools", tool + b"." + part, *args)
 
 
 def _toollist(ui, tool, part):
     return ui.configlist(b"merge-tools", tool + b"." + part)
 
 
 internals = {}
 # Merge tools to document.
 internalsdoc = {}
 
 internaltool = registrar.internalmerge()
 
 # internal tool merge types
 nomerge = internaltool.nomerge
 mergeonly = internaltool.mergeonly  # just the full merge, no premerge
 fullmerge = internaltool.fullmerge  # both premerge and merge
 
 # IMPORTANT: keep the last line of this prompt very short ("What do you want to
 # do?") because of issue6158, ideally to <40 English characters (to allow other
 # languages that may take more columns to still have a chance to fit in an
 # 80-column screen).
 _localchangedotherdeletedmsg = _(
     b"file '%(fd)s' was deleted in other%(o)s but was modified in local%(l)s.\n"
     b"You can use (c)hanged version, (d)elete, or leave (u)nresolved.\n"
     b"What do you want to do?"
     b"$$ &Changed $$ &Delete $$ &Unresolved"
 )
 
 _otherchangedlocaldeletedmsg = _(
     b"file '%(fd)s' was deleted in local%(l)s but was modified in other%(o)s.\n"
     b"You can use (c)hanged version, leave (d)eleted, or leave (u)nresolved.\n"
     b"What do you want to do?"
     b"$$ &Changed $$ &Deleted $$ &Unresolved"
 )
 
 
 class absentfilectx(object):
     """Represents a file that's ostensibly in a context but is actually not
     present in it.
 
     This is here because it's very specific to the filemerge code for now --
     other code is likely going to break with the values this returns."""
 
     def __init__(self, ctx, f):
         self._ctx = ctx
         self._f = f
 
     def __bytes__(self):
         return b'absent file %s@%s' % (self._f, self._ctx)
 
     def path(self):
         return self._f
 
     def size(self):
         return None
 
     def data(self):
         return None
 
     def filenode(self):
         return nullid
 
     _customcmp = True
 
     def cmp(self, fctx):
         """compare with other file context
 
         returns True if different from fctx.
         """
         return not (
             fctx.isabsent()
             and fctx.changectx() == self.changectx()
             and fctx.path() == self.path()
         )
 
     def flags(self):
         return b''
 
     def changectx(self):
         return self._ctx
 
     def isbinary(self):
         return False
 
     def isabsent(self):
         return True
 
 
 def _findtool(ui, tool):
     if tool in internals:
         return tool
     cmd = _toolstr(ui, tool, b"executable", tool)
     if cmd.startswith(b'python:'):
         return cmd
     return findexternaltool(ui, tool)
 
 
 def _quotetoolpath(cmd):
     if cmd.startswith(b'python:'):
         return cmd
     return procutil.shellquote(cmd)
 
 
 def findexternaltool(ui, tool):
     for kn in (b"regkey", b"regkeyalt"):
         k = _toolstr(ui, tool, kn)
         if not k:
             continue
         p = util.lookupreg(k, _toolstr(ui, tool, b"regname"))
         if p:
             p = procutil.findexe(p + _toolstr(ui, tool, b"regappend", b""))
             if p:
                 return p
     exe = _toolstr(ui, tool, b"executable", tool)
     return procutil.findexe(util.expandpath(exe))
 
 
 def _picktool(repo, ui, path, binary, symlink, changedelete):
     strictcheck = ui.configbool(b'merge', b'strict-capability-check')
 
     def hascapability(tool, capability, strict=False):
         if tool in internals:
             return strict and internals[tool].capabilities.get(capability)
         return _toolbool(ui, tool, capability)
 
     def supportscd(tool):
         return tool in internals and internals[tool].mergetype == nomerge
 
     def check(tool, pat, symlink, binary, changedelete):
         tmsg = tool
         if pat:
             tmsg = _(b"%s (for pattern %s)") % (tool, pat)
         if not _findtool(ui, tool):
             if pat:  # explicitly requested tool deserves a warning
                 ui.warn(_(b"couldn't find merge tool %s\n") % tmsg)
             else:  # configured but non-existing tools are more silent
                 ui.note(_(b"couldn't find merge tool %s\n") % tmsg)
         elif symlink and not hascapability(tool, b"symlink", strictcheck):
             ui.warn(_(b"tool %s can't handle symlinks\n") % tmsg)
         elif binary and not hascapability(tool, b"binary", strictcheck):
             ui.warn(_(b"tool %s can't handle binary\n") % tmsg)
         elif changedelete and not supportscd(tool):
             # the nomerge tools are the only tools that support change/delete
             # conflicts
             pass
         elif not procutil.gui() and _toolbool(ui, tool, b"gui"):
             ui.warn(_(b"tool %s requires a GUI\n") % tmsg)
         else:
             return True
         return False
 
     # internal config: ui.forcemerge
     # forcemerge comes from command line arguments, highest priority
     force = ui.config(b'ui', b'forcemerge')
     if force:
         toolpath = _findtool(ui, force)
         if changedelete and not supportscd(toolpath):
             return b":prompt", None
         else:
             if toolpath:
                 return (force, _quotetoolpath(toolpath))
             else:
                 # mimic HGMERGE if given tool not found
                 return (force, force)
 
     # HGMERGE takes next precedence
     hgmerge = encoding.environ.get(b"HGMERGE")
     if hgmerge:
         if changedelete and not supportscd(hgmerge):
             return b":prompt", None
         else:
             return (hgmerge, hgmerge)
 
     # then patterns
 
     # whether binary capability should be checked strictly
     binarycap = binary and strictcheck
 
     for pat, tool in ui.configitems(b"merge-patterns"):
         mf = match.match(repo.root, b'', [pat])
         if mf(path) and check(tool, pat, symlink, binarycap, changedelete):
             if binary and not hascapability(tool, b"binary", strict=True):
                 ui.warn(
                     _(
                         b"warning: check merge-patterns configurations,"
                         b" if %r for binary file %r is unintentional\n"
                         b"(see 'hg help merge-tools'"
                         b" for binary files capability)\n"
                     )
                     % (pycompat.bytestr(tool), pycompat.bytestr(path))
                 )
             toolpath = _findtool(ui, tool)
             return (tool, _quotetoolpath(toolpath))
 
     # then merge tools
     tools = {}
     disabled = set()
     for k, v in ui.configitems(b"merge-tools"):
         t = k.split(b'.')[0]
         if t not in tools:
             tools[t] = int(_toolstr(ui, t, b"priority"))
         if _toolbool(ui, t, b"disabled"):
             disabled.add(t)
     names = tools.keys()
     tools = sorted(
         [(-p, tool) for tool, p in tools.items() if tool not in disabled]
     )
     uimerge = ui.config(b"ui", b"merge")
     if uimerge:
         # external tools defined in uimerge won't be able to handle
         # change/delete conflicts
         if check(uimerge, path, symlink, binary, changedelete):
             if uimerge not in names and not changedelete:
                 return (uimerge, uimerge)
             tools.insert(0, (None, uimerge))  # highest priority
     tools.append((None, b"hgmerge"))  # the old default, if found
     for p, t in tools:
         if check(t, None, symlink, binary, changedelete):
             toolpath = _findtool(ui, t)
             return (t, _quotetoolpath(toolpath))
 
     # internal merge or prompt as last resort
     if symlink or binary or changedelete:
         if not changedelete and len(tools):
             # any tool is rejected by capability for symlink or binary
             ui.warn(_(b"no tool found to merge %s\n") % path)
         return b":prompt", None
     return b":merge", None
 
 
 def _eoltype(data):
     """Guess the EOL type of a file"""
     if b'\0' in data:  # binary
         return None
     if b'\r\n' in data:  # Windows
         return b'\r\n'
     if b'\r' in data:  # Old Mac
         return b'\r'
     if b'\n' in data:  # UNIX
         return b'\n'
     return None  # unknown
 
 
 def _matcheol(file, back):
     """Convert EOL markers in a file to match origfile"""
     tostyle = _eoltype(back.data())  # No repo.wread filters?
     if tostyle:
         data = util.readfile(file)
         style = _eoltype(data)
         if style:
             newdata = data.replace(style, tostyle)
             if newdata != data:
                 util.writefile(file, newdata)
 
 
 @internaltool(b'prompt', nomerge)
 def _iprompt(repo, mynode, orig, fcd, fco, fca, toolconf, labels=None):
     """Asks the user which of the local `p1()` or the other `p2()` version to
     keep as the merged version."""
     ui = repo.ui
     fd = fcd.path()
     uipathfn = scmutil.getuipathfn(repo)
 
     # Avoid prompting during an in-memory merge since it doesn't support merge
     # conflicts.
     if fcd.changectx().isinmemory():
         raise error.InMemoryMergeConflictsError(
             b'in-memory merge does not support file conflicts'
         )
 
     prompts = partextras(labels)
     prompts[b'fd'] = uipathfn(fd)
     try:
         if fco.isabsent():
             index = ui.promptchoice(_localchangedotherdeletedmsg % prompts, 2)
             choice = [b'local', b'other', b'unresolved'][index]
         elif fcd.isabsent():
             index = ui.promptchoice(_otherchangedlocaldeletedmsg % prompts, 2)
             choice = [b'other', b'local', b'unresolved'][index]
         else:
             # IMPORTANT: keep the last line of this prompt ("What do you want to
             # do?") very short, see comment next to _localchangedotherdeletedmsg
             # at the top of the file for details.
             index = ui.promptchoice(
                 _(
                     b"file '%(fd)s' needs to be resolved.\n"
                     b"You can keep (l)ocal%(l)s, take (o)ther%(o)s, or leave "
                     b"(u)nresolved.\n"
                     b"What do you want to do?"
                     b"$$ &Local $$ &Other $$ &Unresolved"
                 )
                 % prompts,
                 2,
             )
             choice = [b'local', b'other', b'unresolved'][index]
 
         if choice == b'other':
             return _iother(repo, mynode, orig, fcd, fco, fca, toolconf, labels)
         elif choice == b'local':
             return _ilocal(repo, mynode, orig, fcd, fco, fca, toolconf, labels)
         elif choice == b'unresolved':
             return _ifail(repo, mynode, orig, fcd, fco, fca, toolconf, labels)
     except error.ResponseExpected:
         ui.write(b"\n")
         return _ifail(repo, mynode, orig, fcd, fco, fca, toolconf, labels)
 
 
 @internaltool(b'local', nomerge)
 def _ilocal(repo, mynode, orig, fcd, fco, fca, toolconf, labels=None):
     """Uses the local `p1()` version of files as the merged version."""
     return 0, fcd.isabsent()
 
 
 @internaltool(b'other', nomerge)
 def _iother(repo, mynode, orig, fcd, fco, fca, toolconf, labels=None):
     """Uses the other `p2()` version of files as the merged version."""
     if fco.isabsent():
         # local changed, remote deleted -- 'deleted' picked
         _underlyingfctxifabsent(fcd).remove()
         deleted = True
     else:
         _underlyingfctxifabsent(fcd).write(fco.data(), fco.flags())
         deleted = False
     return 0, deleted
 
 
 @internaltool(b'fail', nomerge)
 def _ifail(repo, mynode, orig, fcd, fco, fca, toolconf, labels=None):
     """
     Rather than attempting to merge files that were modified on both
     branches, it marks them as unresolved. The resolve command must be
     used to resolve these conflicts."""
     # for change/delete conflicts write out the changed version, then fail
     if fcd.isabsent():
         _underlyingfctxifabsent(fcd).write(fco.data(), fco.flags())
     return 1, False
 
 
 def _underlyingfctxifabsent(filectx):
     """Sometimes when resolving, our fcd is actually an absentfilectx, but
     we want to write to it (to do the resolve). This helper returns the
     underyling workingfilectx in that case.
     """
     if filectx.isabsent():
         return filectx.changectx()[filectx.path()]
     else:
         return filectx
 
 
 def _premerge(repo, fcd, fco, fca, toolconf, files, labels=None):
     tool, toolpath, binary, symlink, scriptfn = toolconf
     if symlink or fcd.isabsent() or fco.isabsent():
         return 1
     unused, unused, unused, back = files
 
     ui = repo.ui
 
     validkeep = [b'keep', b'keep-merge3']
 
     # do we attempt to simplemerge first?
     try:
         premerge = _toolbool(ui, tool, b"premerge", not binary)
     except error.ConfigError:
         premerge = _toolstr(ui, tool, b"premerge", b"").lower()
         if premerge not in validkeep:
             _valid = b', '.join([b"'" + v + b"'" for v in validkeep])
             raise error.ConfigError(
                 _(b"%s.premerge not valid ('%s' is neither boolean nor %s)")
                 % (tool, premerge, _valid)
             )
 
     if premerge:
         if premerge == b'keep-merge3':
             if not labels:
                 labels = _defaultconflictlabels
             if len(labels) < 3:
                 labels.append(b'base')
         r = simplemerge.simplemerge(ui, fcd, fca, fco, quiet=True, label=labels)
         if not r:
             ui.debug(b" premerge successful\n")
             return 0
         if premerge not in validkeep:
             # restore from backup and try again
             _restorebackup(fcd, back)
     return 1  # continue merging
 
 
 def _mergecheck(repo, mynode, orig, fcd, fco, fca, toolconf):
     tool, toolpath, binary, symlink, scriptfn = toolconf
     uipathfn = scmutil.getuipathfn(repo)
     if symlink:
         repo.ui.warn(
             _(b'warning: internal %s cannot merge symlinks for %s\n')
             % (tool, uipathfn(fcd.path()))
         )
         return False
     if fcd.isabsent() or fco.isabsent():
         repo.ui.warn(
             _(
                 b'warning: internal %s cannot merge change/delete '
                 b'conflict for %s\n'
             )
             % (tool, uipathfn(fcd.path()))
         )
         return False
     return True
 
 
 def _merge(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels, mode):
     """
     Uses the internal non-interactive simple merge algorithm for merging
     files. It will fail if there are any conflicts and leave markers in
     the partially merged file. Markers will have two sections, one for each side
     of merge, unless mode equals 'union' which suppresses the markers."""
     ui = repo.ui
 
     r = simplemerge.simplemerge(ui, fcd, fca, fco, label=labels, mode=mode)
     return True, r, False
 
 
 @internaltool(
     b'union',
     fullmerge,
     _(
         b"warning: conflicts while merging %s! "
         b"(edit, then use 'hg resolve --mark')\n"
     ),
     precheck=_mergecheck,
 )
 def _iunion(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None):
     """
     Uses the internal non-interactive simple merge algorithm for merging
     files. It will use both left and right sides for conflict regions.
     No markers are inserted."""
     return _merge(
         repo, mynode, orig, fcd, fco, fca, toolconf, files, labels, b'union'
     )
 
 
 @internaltool(
     b'merge',
     fullmerge,
     _(
         b"warning: conflicts while merging %s! "
         b"(edit, then use 'hg resolve --mark')\n"
     ),
     precheck=_mergecheck,
 )
 def _imerge(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None):
     """
     Uses the internal non-interactive simple merge algorithm for merging
     files. It will fail if there are any conflicts and leave markers in
     the partially merged file. Markers will have two sections, one for each side
     of merge."""
     return _merge(
         repo, mynode, orig, fcd, fco, fca, toolconf, files, labels, b'merge'
     )
 
 
 @internaltool(
     b'merge3',
     fullmerge,
     _(
         b"warning: conflicts while merging %s! "
         b"(edit, then use 'hg resolve --mark')\n"
     ),
     precheck=_mergecheck,
 )
 def _imerge3(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None):
     """
     Uses the internal non-interactive simple merge algorithm for merging
     files. It will fail if there are any conflicts and leave markers in
     the partially merged file. Marker will have three sections, one from each
     side of the merge and one for the base content."""
     if not labels:
         labels = _defaultconflictlabels
     if len(labels) < 3:
         labels.append(b'base')
     return _imerge(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels)
 
 
+@internaltool(
+    b'mergediff',
+    fullmerge,
+    _(
+        b"warning: conflicts while merging %s! "
+        b"(edit, then use 'hg resolve --mark')\n"
+    ),
+    precheck=_mergecheck,
+)
+def _imerge_diff(
+    repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None
+):
+    """
+    Uses the internal non-interactive simple merge algorithm for merging
+    files. It will fail if there are any conflicts and leave markers in
+    the partially merged file. The marker will have two sections, one with the
+    content from one side of the merge, and one with a diff from the base
+    content to the content on the other side. (experimental)"""
+    if not labels:
+        labels = _defaultconflictlabels
+    if len(labels) < 3:
+        labels.append(b'base')
+    return _merge(
+        repo, mynode, orig, fcd, fco, fca, toolconf, files, labels, b'mergediff'
+    )
+
+
 def _imergeauto(
     repo,
     mynode,
     orig,
     fcd,
     fco,
     fca,
     toolconf,
     files,
     labels=None,
     localorother=None,
 ):
     """
     Generic driver for _imergelocal and _imergeother
     """
     assert localorother is not None
     r = simplemerge.simplemerge(
         repo.ui, fcd, fca, fco, label=labels, localorother=localorother
     )
     return True, r
 
 
 @internaltool(b'merge-local', mergeonly, precheck=_mergecheck)
 def _imergelocal(*args, **kwargs):
     """
     Like :merge, but resolve all conflicts non-interactively in favor
     of the local `p1()` changes."""
     success, status = _imergeauto(localorother=b'local', *args, **kwargs)
     return success, status, False
 
 
 @internaltool(b'merge-other', mergeonly, precheck=_mergecheck)
 def _imergeother(*args, **kwargs):
     """
     Like :merge, but resolve all conflicts non-interactively in favor
     of the other `p2()` changes."""
     success, status = _imergeauto(localorother=b'other', *args, **kwargs)
     return success, status, False
 
 
 @internaltool(
     b'tagmerge',
     mergeonly,
     _(
         b"automatic tag merging of %s failed! "
         b"(use 'hg resolve --tool :merge' or another merge "
         b"tool of your choice)\n"
     ),
 )
 def _itagmerge(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None):
     """
     Uses the internal tag merge algorithm (experimental).
     """
     success, status = tagmerge.merge(repo, fcd, fco, fca)
     return success, status, False
 
 
 @internaltool(b'dump', fullmerge, binary=True, symlink=True)
 def _idump(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None):
     """
     Creates three versions of the files to merge, containing the
     contents of local, other and base. These files can then be used to
     perform a merge manually. If the file to be merged is named
     ``a.txt``, these files will accordingly be named ``a.txt.local``,
     ``a.txt.other`` and ``a.txt.base`` and they will be placed in the
     same directory as ``a.txt``.
 
     This implies premerge. Therefore, files aren't dumped, if premerge
     runs successfully. Use :forcedump to forcibly write files out.
     """
     a = _workingpath(repo, fcd)
     fd = fcd.path()
 
     from . import context
 
     if isinstance(fcd, context.overlayworkingfilectx):
         raise error.InMemoryMergeConflictsError(
             b'in-memory merge does not support the :dump tool.'
         )
 
     util.writefile(a + b".local", fcd.decodeddata())
     repo.wwrite(fd + b".other", fco.data(), fco.flags())
     repo.wwrite(fd + b".base", fca.data(), fca.flags())
     return False, 1, False
 
 
 @internaltool(b'forcedump', mergeonly, binary=True, symlink=True)
 def _forcedump(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None):
     """
     Creates three versions of the files as same as :dump, but omits premerge.
     """
     return _idump(
         repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=labels
     )
 
 
 def _xmergeimm(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels=None):
     # In-memory merge simply raises an exception on all external merge tools,
     # for now.
     #
     # It would be possible to run most tools with temporary files, but this
     # raises the question of what to do if the user only partially resolves the
     # file -- we can't leave a merge state. (Copy to somewhere in the .hg/
     # directory and tell the user how to get it is my best idea, but it's
     # clunky.)
     raise error.InMemoryMergeConflictsError(
         b'in-memory merge does not support external merge tools'
     )
 
 
 def _describemerge(ui, repo, mynode, fcl, fcb, fco, env, toolpath, args):
     tmpl = ui.config(b'command-templates', b'pre-merge-tool-output')
     if not tmpl:
         return
 
     mappingdict = templateutil.mappingdict
     props = {
         b'ctx': fcl.changectx(),
         b'node': hex(mynode),
         b'path': fcl.path(),
         b'local': mappingdict(
             {
                 b'ctx': fcl.changectx(),
                 b'fctx': fcl,
                 b'node': hex(mynode),
                 b'name': _(b'local'),
                 b'islink': b'l' in fcl.flags(),
                 b'label': env[b'HG_MY_LABEL'],
             }
         ),
         b'base': mappingdict(
             {
                 b'ctx': fcb.changectx(),
                 b'fctx': fcb,
                 b'name': _(b'base'),
                 b'islink': b'l' in fcb.flags(),
                 b'label': env[b'HG_BASE_LABEL'],
             }
         ),
         b'other': mappingdict(
             {
                 b'ctx': fco.changectx(),
                 b'fctx': fco,
                 b'name': _(b'other'),
                 b'islink': b'l' in fco.flags(),
                 b'label': env[b'HG_OTHER_LABEL'],
             }
         ),
         b'toolpath': toolpath,
         b'toolargs': args,
     }
 
     # TODO: make all of this something that can be specified on a per-tool basis
     tmpl = templater.unquotestring(tmpl)
 
     # Not using cmdutil.rendertemplate here since it causes errors importing
     # things for us to import cmdutil.
     tres = formatter.templateresources(ui, repo)
     t = formatter.maketemplater(
         ui, tmpl, defaults=templatekw.keywords, resources=tres
     )
     ui.status(t.renderdefault(props))
 
 
 def _xmerge(repo, mynode, orig, fcd, fco, fca, toolconf, files, labels):
     tool, toolpath, binary, symlink, scriptfn = toolconf
     uipathfn = scmutil.getuipathfn(repo)
     if fcd.isabsent() or fco.isabsent():
         repo.ui.warn(
             _(b'warning: %s cannot merge change/delete conflict for %s\n')
             % (tool, uipathfn(fcd.path()))
         )
         return False, 1, None
     unused, unused, unused, back = files
     localpath = _workingpath(repo, fcd)
     args = _toolstr(repo.ui, tool, b"args")
 
     with _maketempfiles(
         repo, fco, fca, repo.wvfs.join(back.path()), b"$output" in args
     ) as temppaths:
         basepath, otherpath, localoutputpath = temppaths
         outpath = b""
         mylabel, otherlabel = labels[:2]
         if len(labels) >= 3:
             baselabel = labels[2]
         else:
             baselabel = b'base'
         env = {
             b'HG_FILE': fcd.path(),
             b'HG_MY_NODE': short(mynode),
             b'HG_OTHER_NODE': short(fco.changectx().node()),
             b'HG_BASE_NODE': short(fca.changectx().node()),
             b'HG_MY_ISLINK': b'l' in fcd.flags(),
             b'HG_OTHER_ISLINK': b'l' in fco.flags(),
             b'HG_BASE_ISLINK': b'l' in fca.flags(),
             b'HG_MY_LABEL': mylabel,
             b'HG_OTHER_LABEL': otherlabel,
             b'HG_BASE_LABEL': baselabel,
         }
         ui = repo.ui
 
         if b"$output" in args:
             # read input from backup, write to original
             outpath = localpath
             localpath = localoutputpath
         replace = {
             b'local': localpath,
             b'base': basepath,
             b'other': otherpath,
             b'output': outpath,
             b'labellocal': mylabel,
             b'labelother': otherlabel,
             b'labelbase': baselabel,
         }
         args = util.interpolate(
             br'\$',
             replace,
             args,
             lambda s: procutil.shellquote(util.localpath(s)),
         )
         if _toolbool(ui, tool, b"gui"):
             repo.ui.status(
                 _(b'running merge tool %s for file %s\n')
                 % (tool, uipathfn(fcd.path()))
             )
         if scriptfn is None:
             cmd = toolpath + b' ' + args
             repo.ui.debug(b'launching merge tool: %s\n' % cmd)
             _describemerge(ui, repo, mynode, fcd, fca, fco, env, toolpath, args)
             r = ui.system(
                 cmd, cwd=repo.root, environ=env, blockedtag=b'mergetool'
             )
         else:
             repo.ui.debug(
                 b'launching python merge script: %s:%s\n' % (toolpath, scriptfn)
             )
             r = 0
             try:
                 # avoid cycle cmdutil->merge->filemerge->extensions->cmdutil
                 from . import extensions
 
                 mod = extensions.loadpath(toolpath, b'hgmerge.%s' % tool)
             except Exception:
                 raise error.Abort(
                     _(b"loading python merge script failed: %s") % toolpath
                 )
             mergefn = getattr(mod, scriptfn, None)
             if mergefn is None:
                 raise error.Abort(
                     _(b"%s does not have function: %s") % (toolpath, scriptfn)
                 )
             argslist = procutil.shellsplit(args)
             # avoid cycle cmdutil->merge->filemerge->hook->extensions->cmdutil
             from . import hook
 
             ret, raised = hook.pythonhook(
                 ui, repo, b"merge", toolpath, mergefn, {b'args': argslist}, True
             )
             if raised:
                 r = 1
         repo.ui.debug(b'merge tool returned: %d\n' % r)
         return True, r, False
 
 
 def _formatconflictmarker(ctx, template, label, pad):
     """Applies the given template to the ctx, prefixed by the label.
 
     Pad is the minimum width of the label prefix, so that multiple markers
     can have aligned templated parts.
     """
     if ctx.node() is None:
         ctx = ctx.p1()
 
     props = {b'ctx': ctx}
     templateresult = template.renderdefault(props)
 
     label = (b'%s:' % label).ljust(pad + 1)
     mark = b'%s %s' % (label, templateresult)
 
     if mark:
         mark = mark.splitlines()[0]  # split for safety
 
     # 8 for the prefix of conflict marker lines (e.g. '<<<<<<< ')
     return stringutil.ellipsis(mark, 80 - 8)
 
 
 _defaultconflictlabels = [b'local', b'other']
 
 
 def _formatlabels(repo, fcd, fco, fca, labels, tool=None):
     """Formats the given labels using the conflict marker template.
 
     Returns a list of formatted labels.
     """
     cd = fcd.changectx()
     co = fco.changectx()
     ca = fca.changectx()
 
     ui = repo.ui
     template = ui.config(b'command-templates', b'mergemarker')
     if tool is not None:
         template = _toolstr(ui, tool, b'mergemarkertemplate', template)
     template = templater.unquotestring(template)
     tres = formatter.templateresources(ui, repo)
     tmpl = formatter.maketemplater(
         ui, template, defaults=templatekw.keywords, resources=tres
     )
 
     pad = max(len(l) for l in labels)
 
     newlabels = [
         _formatconflictmarker(cd, tmpl, labels[0], pad),
         _formatconflictmarker(co, tmpl, labels[1], pad),
     ]
     if len(labels) > 2:
         newlabels.append(_formatconflictmarker(ca, tmpl, labels[2], pad))
     return newlabels
 
 
 def partextras(labels):
     """Return a dictionary of extra labels for use in prompts to the user
 
     Intended use is in strings of the form "(l)ocal%(l)s".
     """
     if labels is None:
         return {
             b"l": b"",
             b"o": b"",
         }
 
     return {
         b"l": b" [%s]" % labels[0],
         b"o": b" [%s]" % labels[1],
     }
 
 
 def _restorebackup(fcd, back):
     # TODO: Add a workingfilectx.write(otherfilectx) path so we can use
     # util.copy here instead.
     fcd.write(back.data(), fcd.flags())
 
 
 def _makebackup(repo, ui, wctx, fcd, premerge):
     """Makes and returns a filectx-like object for ``fcd``'s backup file.
 
     In addition to preserving the user's pre-existing modifications to `fcd`
     (if any), the backup is used to undo certain premerges, confirm whether a
     merge changed anything, and determine what line endings the new file should
     have.
 
     Backups only need to be written once (right before the premerge) since their
     content doesn't change afterwards.
     """
     if fcd.isabsent():
         return None
     # TODO: Break this import cycle somehow. (filectx -> ctx -> fileset ->
     # merge -> filemerge). (I suspect the fileset import is the weakest link)
     from . import context
 
     back = scmutil.backuppath(ui, repo, fcd.path())
     inworkingdir = back.startswith(repo.wvfs.base) and not back.startswith(
         repo.vfs.base
     )
     if isinstance(fcd, context.overlayworkingfilectx) and inworkingdir:
         # If the backup file is to be in the working directory, and we're
         # merging in-memory, we must redirect the backup to the memory context
         # so we don't disturb the working directory.
         relpath = back[len(repo.wvfs.base) + 1 :]
         if premerge:
             wctx[relpath].write(fcd.data(), fcd.flags())
         return wctx[relpath]
     else:
         if premerge:
             # Otherwise, write to wherever path the user specified the backups
             # should go. We still need to switch based on whether the source is
             # in-memory so we can use the fast path of ``util.copy`` if both are
             # on disk.
             if isinstance(fcd, context.overlayworkingfilectx):
                 util.writefile(back, fcd.data())
             else:
                 a = _workingpath(repo, fcd)
                 util.copyfile(a, back)
         # A arbitraryfilectx is returned, so we can run the same functions on
         # the backup context regardless of where it lives.
         return context.arbitraryfilectx(back, repo=repo)
 
 
 @contextlib.contextmanager
 def _maketempfiles(repo, fco, fca, localpath, uselocalpath):
     """Writes out `fco` and `fca` as temporary files, and (if uselocalpath)
     copies `localpath` to another temporary file, so an external merge tool may
     use them.
     """
     tmproot = None
     tmprootprefix = repo.ui.config(b'experimental', b'mergetempdirprefix')
     if tmprootprefix:
         tmproot = pycompat.mkdtemp(prefix=tmprootprefix)
 
     def maketempfrompath(prefix, path):
         fullbase, ext = os.path.splitext(path)
         pre = b"%s~%s" % (os.path.basename(fullbase), prefix)
         if tmproot:
             name = os.path.join(tmproot, pre)
             if ext:
                 name += ext
             f = open(name, "wb")
         else:
             fd, name = pycompat.mkstemp(prefix=pre + b'.', suffix=ext)
             f = os.fdopen(fd, "wb")
         return f, name
 
     def tempfromcontext(prefix, ctx):
         f, name = maketempfrompath(prefix, ctx.path())
         data = repo.wwritedata(ctx.path(), ctx.data())
         f.write(data)
         f.close()
         return name
 
     b = tempfromcontext(b"base", fca)
     c = tempfromcontext(b"other", fco)
     d = localpath
     if uselocalpath:
         # We start off with this being the backup filename, so remove the .orig
         # to make syntax-highlighting more likely.
         if d.endswith(b'.orig'):
             d, _ = os.path.splitext(d)
         f, d = maketempfrompath(b"local", d)
         with open(localpath, b'rb') as src:
             f.write(src.read())
         f.close()
 
     try:
         yield b, c, d
     finally:
         if tmproot:
             shutil.rmtree(tmproot)
         else:
             util.unlink(b)
             util.unlink(c)
             # if not uselocalpath, d is the 'orig'/backup file which we
             # shouldn't delete.
             if d and uselocalpath:
                 util.unlink(d)
 
 
 def _filemerge(premerge, repo, wctx, mynode, orig, fcd, fco, fca, labels=None):
     """perform a 3-way merge in the working directory
 
     premerge = whether this is a premerge
     mynode = parent node before merge
     orig = original local filename before merge
     fco = other file context
     fca = ancestor file context
     fcd = local file context for current/destination file
 
     Returns whether the merge is complete, the return value of the merge, and
     a boolean indicating whether the file was deleted from disk."""
 
     if not fco.cmp(fcd):  # files identical?
         return True, None, False
 
     ui = repo.ui
     fd = fcd.path()
     uipathfn = scmutil.getuipathfn(repo)
     fduipath = uipathfn(fd)
     binary = fcd.isbinary() or fco.isbinary() or fca.isbinary()
     symlink = b'l' in fcd.flags() + fco.flags()
     changedelete = fcd.isabsent() or fco.isabsent()
     tool, toolpath = _picktool(repo, ui, fd, binary, symlink, changedelete)
     scriptfn = None
     if tool in internals and tool.startswith(b'internal:'):
         # normalize to new-style names (':merge' etc)
         tool = tool[len(b'internal') :]
     if toolpath and toolpath.startswith(b'python:'):
         invalidsyntax = False
         if toolpath.count(b':') >= 2:
             script, scriptfn = toolpath[7:].rsplit(b':', 1)
             if not scriptfn:
                 invalidsyntax = True
             # missing :callable can lead to spliting on windows drive letter
             if b'\\' in scriptfn or b'/' in scriptfn:
                 invalidsyntax = True
         else:
             invalidsyntax = True
         if invalidsyntax:
             raise error.Abort(_(b"invalid 'python:' syntax: %s") % toolpath)
         toolpath = script
     ui.debug(
         b"picked tool '%s' for %s (binary %s symlink %s changedelete %s)\n"
         % (
             tool,
             fduipath,
             pycompat.bytestr(binary),
             pycompat.bytestr(symlink),
             pycompat.bytestr(changedelete),
         )
     )
 
     if tool in internals:
         func = internals[tool]
         mergetype = func.mergetype
         onfailure = func.onfailure
         precheck = func.precheck
         isexternal = False
     else:
         if wctx.isinmemory():
             func = _xmergeimm
         else:
             func = _xmerge
         mergetype = fullmerge
         onfailure = _(b"merging %s failed!\n")
         precheck = None
         isexternal = True
 
     toolconf = tool, toolpath, binary, symlink, scriptfn
 
     if mergetype == nomerge:
         r, deleted = func(repo, mynode, orig, fcd, fco, fca, toolconf, labels)
         return True, r, deleted
 
     if premerge:
         if orig != fco.path():
             ui.status(
                 _(b"merging %s and %s to %s\n")
                 % (uipathfn(orig), uipathfn(fco.path()), fduipath)
             )
         else:
             ui.status(_(b"merging %s\n") % fduipath)
 
     ui.debug(b"my %s other %s ancestor %s\n" % (fcd, fco, fca))
 
     if precheck and not precheck(repo, mynode, orig, fcd, fco, fca, toolconf):
         if onfailure:
             if wctx.isinmemory():
                 raise error.InMemoryMergeConflictsError(
                     b'in-memory merge does not support merge conflicts'
                 )
             ui.warn(onfailure % fduipath)
         return True, 1, False
 
     back = _makebackup(repo, ui, wctx, fcd, premerge)
     files = (None, None, None, back)
     r = 1
     try:
         internalmarkerstyle = ui.config(b'ui', b'mergemarkers')
         if isexternal:
             markerstyle = _toolstr(ui, tool, b'mergemarkers')
         else:
             markerstyle = internalmarkerstyle
 
         if not labels:
             labels = _defaultconflictlabels
         formattedlabels = labels
         if markerstyle != b'basic':
             formattedlabels = _formatlabels(
                 repo, fcd, fco, fca, labels, tool=tool
             )
 
         if premerge and mergetype == fullmerge:
             # conflict markers generated by premerge will use 'detailed'
             # settings if either ui.mergemarkers or the tool's mergemarkers
             # setting is 'detailed'. This way tools can have basic labels in
             # space-constrained areas of the UI, but still get full information
             # in conflict markers if premerge is 'keep' or 'keep-merge3'.
             premergelabels = labels
             labeltool = None
             if markerstyle != b'basic':
                 # respect 'tool's mergemarkertemplate (which defaults to
                 # command-templates.mergemarker)
                 labeltool = tool
             if internalmarkerstyle != b'basic' or markerstyle != b'basic':
                 premergelabels = _formatlabels(
                     repo, fcd, fco, fca, premergelabels, tool=labeltool
                 )
 
             r = _premerge(
                 repo, fcd, fco, fca, toolconf, files, labels=premergelabels
             )
             # complete if premerge successful (r is 0)
             return not r, r, False
 
         needcheck, r, deleted = func(
             repo,
             mynode,
             orig,
             fcd,
             fco,
             fca,
             toolconf,
             files,
             labels=formattedlabels,
         )
 
         if needcheck:
             r = _check(repo, r, ui, tool, fcd, files)
 
         if r:
             if onfailure:
                 if wctx.isinmemory():
                     raise error.InMemoryMergeConflictsError(
                         b'in-memory merge '
                         b'does not support '
                         b'merge conflicts'
                     )
                 ui.warn(onfailure % fduipath)
             _onfilemergefailure(ui)
 
         return True, r, deleted
     finally:
         if not r and back is not None:
             back.remove()
 
 
 def _haltmerge():
     msg = _(b'merge halted after failed merge (see hg resolve)')
     raise error.InterventionRequired(msg)
 
 
 def _onfilemergefailure(ui):
     action = ui.config(b'merge', b'on-failure')
     if action == b'prompt':
         msg = _(b'continue merge operation (yn)?$$ &Yes $$ &No')
         if ui.promptchoice(msg, 0) == 1:
             _haltmerge()
     if action == b'halt':
         _haltmerge()
     # default action is 'continue', in which case we neither prompt nor halt
 
 
 def hasconflictmarkers(data):
     return bool(
         re.search(b"^(<<<<<<< .*|=======|>>>>>>> .*)$", data, re.MULTILINE)
     )
 
 
 def _check(repo, r, ui, tool, fcd, files):
     fd = fcd.path()
     uipathfn = scmutil.getuipathfn(repo)
     unused, unused, unused, back = files
 
     if not r and (
         _toolbool(ui, tool, b"checkconflicts")
         or b'conflicts' in _toollist(ui, tool, b"check")
     ):
         if hasconflictmarkers(fcd.data()):
             r = 1
 
     checked = False
     if b'prompt' in _toollist(ui, tool, b"check"):
         checked = True
         if ui.promptchoice(
             _(b"was merge of '%s' successful (yn)?$$ &Yes $$ &No")
             % uipathfn(fd),
             1,
         ):
             r = 1
 
     if (
         not r
         and not checked
         and (
             _toolbool(ui, tool, b"checkchanged")
             or b'changed' in _toollist(ui, tool, b"check")
         )
     ):
         if back is not None and not fcd.cmp(back):
             if ui.promptchoice(
                 _(
                     b" output file %s appears unchanged\n"
                     b"was merge successful (yn)?"
                     b"$$ &Yes $$ &No"
                 )
                 % uipathfn(fd),
                 1,
             ):
                 r = 1
 
     if back is not None and _toolbool(ui, tool, b"fixeol"):
         _matcheol(_workingpath(repo, fcd), back)
 
     return r
 
 
 def _workingpath(repo, ctx):
     return repo.wjoin(ctx.path())
 
 
 def premerge(repo, wctx, mynode, orig, fcd, fco, fca, labels=None):
     return _filemerge(
         True, repo, wctx, mynode, orig, fcd, fco, fca, labels=labels
     )
 
 
 def filemerge(repo, wctx, mynode, orig, fcd, fco, fca, labels=None):
     return _filemerge(
         False, repo, wctx, mynode, orig, fcd, fco, fca, labels=labels
     )
 
 
 def loadinternalmerge(ui, extname, registrarobj):
     """Load internal merge tool from specified registrarobj"""
     for name, func in pycompat.iteritems(registrarobj._table):
         fullname = b':' + name
         internals[fullname] = func
         internals[b'internal:' + name] = func
         internalsdoc[fullname] = func
 
         capabilities = sorted([k for k, v in func.capabilities.items() if v])
         if capabilities:
             capdesc = b"    (actual capabilities: %s)" % b', '.join(
                 capabilities
             )
             func.__doc__ = func.__doc__ + pycompat.sysstr(b"\n\n%s" % capdesc)
 
     # to put i18n comments into hg.pot for automatically generated texts
 
     # i18n: "binary" and "symlink" are keywords
     # i18n: this text is added automatically
     _(b"    (actual capabilities: binary, symlink)")
     # i18n: "binary" is keyword
     # i18n: this text is added automatically
     _(b"    (actual capabilities: binary)")
     # i18n: "symlink" is keyword
     # i18n: this text is added automatically
     _(b"    (actual capabilities: symlink)")
 
 
 # load built-in merge tools explicitly to setup internalsdoc
 loadinternalmerge(None, None, internaltool)
 
 # tell hggettext to extract docstrings from these functions:
 i18nfunctions = internals.values()

mercurial/simplemerge.py

@@ -1,523 +1,591 b''
 # Copyright (C) 2004, 2005 Canonical Ltd
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation; either version 2 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program; if not, see <http://www.gnu.org/licenses/>.
 
 # mbp: "you know that thing where cvs gives you conflict markers?"
 # s: "i hate that."
 
 from __future__ import absolute_import
 
 from .i18n import _
 from . import (
     error,
     mdiff,
     node as nodemod,
     pycompat,
     util,
 )
 from .utils import stringutil
 
 
 class CantReprocessAndShowBase(Exception):
     pass
 
 
 def intersect(ra, rb):
     """Given two ranges return the range where they intersect or None.
 
     >>> intersect((0, 10), (0, 6))
     (0, 6)
     >>> intersect((0, 10), (5, 15))
     (5, 10)
     >>> intersect((0, 10), (10, 15))
     >>> intersect((0, 9), (10, 15))
     >>> intersect((0, 9), (7, 15))
     (7, 9)
     """
     assert ra[0] <= ra[1]
     assert rb[0] <= rb[1]
 
     sa = max(ra[0], rb[0])
     sb = min(ra[1], rb[1])
     if sa < sb:
         return sa, sb
     else:
         return None
 
 
 def compare_range(a, astart, aend, b, bstart, bend):
     """Compare a[astart:aend] == b[bstart:bend], without slicing."""
     if (aend - astart) != (bend - bstart):
         return False
     for ia, ib in zip(
         pycompat.xrange(astart, aend), pycompat.xrange(bstart, bend)
     ):
         if a[ia] != b[ib]:
             return False
     else:
         return True
 
 
 class Merge3Text(object):
     """3-way merge of texts.
 
     Given strings BASE, OTHER, THIS, tries to produce a combined text
     incorporating the changes from both BASE->OTHER and BASE->THIS."""
 
     def __init__(self, basetext, atext, btext, base=None, a=None, b=None):
         self.basetext = basetext
         self.atext = atext
         self.btext = btext
         if base is None:
             base = mdiff.splitnewlines(basetext)
         if a is None:
             a = mdiff.splitnewlines(atext)
         if b is None:
             b = mdiff.splitnewlines(btext)
         self.base = base
         self.a = a
         self.b = b
 
     def merge_lines(
         self,
         name_a=None,
         name_b=None,
         name_base=None,
         start_marker=b'<<<<<<<',
         mid_marker=b'=======',
         end_marker=b'>>>>>>>',
         base_marker=None,
         localorother=None,
         minimize=False,
     ):
         """Return merge in cvs-like form."""
         self.conflicts = False
         newline = b'\n'
         if len(self.a) > 0:
             if self.a[0].endswith(b'\r\n'):
                 newline = b'\r\n'
             elif self.a[0].endswith(b'\r'):
                 newline = b'\r'
         if name_a and start_marker:
             start_marker = start_marker + b' ' + name_a
         if name_b and end_marker:
             end_marker = end_marker + b' ' + name_b
         if name_base and base_marker:
             base_marker = base_marker + b' ' + name_base
         merge_regions = self.merge_regions()
         if minimize:
             merge_regions = self.minimize(merge_regions)
         for t in merge_regions:
             what = t[0]
             if what == b'unchanged':
                 for i in range(t[1], t[2]):
                     yield self.base[i]
             elif what == b'a' or what == b'same':
                 for i in range(t[1], t[2]):
                     yield self.a[i]
             elif what == b'b':
                 for i in range(t[1], t[2]):
                     yield self.b[i]
             elif what == b'conflict':
                 if localorother == b'local':
                     for i in range(t[3], t[4]):
                         yield self.a[i]
                 elif localorother == b'other':
                     for i in range(t[5], t[6]):
                         yield self.b[i]
                 else:
                     self.conflicts = True
                     if start_marker is not None:
                         yield start_marker + newline
                     for i in range(t[3], t[4]):
                         yield self.a[i]
                     if base_marker is not None:
                         yield base_marker + newline
                         for i in range(t[1], t[2]):
                             yield self.base[i]
                     if mid_marker is not None:
                         yield mid_marker + newline
                     for i in range(t[5], t[6]):
                         yield self.b[i]
                     if end_marker is not None:
                         yield end_marker + newline
             else:
                 raise ValueError(what)
 
     def merge_groups(self):
         """Yield sequence of line groups.  Each one is a tuple:
 
         'unchanged', lines
              Lines unchanged from base
 
         'a', lines
              Lines taken from a
 
         'same', lines
              Lines taken from a (and equal to b)
 
         'b', lines
              Lines taken from b
 
         'conflict', base_lines, a_lines, b_lines
              Lines from base were changed to either a or b and conflict.
         """
         for t in self.merge_regions():
             what = t[0]
             if what == b'unchanged':
                 yield what, self.base[t[1] : t[2]]
             elif what == b'a' or what == b'same':
                 yield what, self.a[t[1] : t[2]]
             elif what == b'b':
                 yield what, self.b[t[1] : t[2]]
             elif what == b'conflict':
                 yield (
                     what,
                     self.base[t[1] : t[2]],
                     self.a[t[3] : t[4]],
                     self.b[t[5] : t[6]],
                 )
             else:
                 raise ValueError(what)
 
     def merge_regions(self):
         """Return sequences of matching and conflicting regions.
 
         This returns tuples, where the first value says what kind we
         have:
 
         'unchanged', start, end
              Take a region of base[start:end]
 
         'same', astart, aend
              b and a are different from base but give the same result
 
         'a', start, end
              Non-clashing insertion from a[start:end]
 
         'conflict', zstart, zend, astart, aend, bstart, bend
             Conflict between a and b, with z as common ancestor
 
         Method is as follows:
 
         The two sequences align only on regions which match the base
         and both descendants.  These are found by doing a two-way diff
         of each one against the base, and then finding the
         intersections between those regions.  These "sync regions"
         are by definition unchanged in both and easily dealt with.
 
         The regions in between can be in any of three cases:
         conflicted, or changed on only one side.
         """
 
         # section a[0:ia] has been disposed of, etc
         iz = ia = ib = 0
 
         for region in self.find_sync_regions():
             zmatch, zend, amatch, aend, bmatch, bend = region
             # print 'match base [%d:%d]' % (zmatch, zend)
 
             matchlen = zend - zmatch
             assert matchlen >= 0
             assert matchlen == (aend - amatch)
             assert matchlen == (bend - bmatch)
 
             len_a = amatch - ia
             len_b = bmatch - ib
             len_base = zmatch - iz
             assert len_a >= 0
             assert len_b >= 0
             assert len_base >= 0
 
             # print 'unmatched a=%d, b=%d' % (len_a, len_b)
 
             if len_a or len_b:
                 # try to avoid actually slicing the lists
                 equal_a = compare_range(
                     self.a, ia, amatch, self.base, iz, zmatch
                 )
                 equal_b = compare_range(
                     self.b, ib, bmatch, self.base, iz, zmatch
                 )
                 same = compare_range(self.a, ia, amatch, self.b, ib, bmatch)
 
                 if same:
                     yield b'same', ia, amatch
                 elif equal_a and not equal_b:
                     yield b'b', ib, bmatch
                 elif equal_b and not equal_a:
                     yield b'a', ia, amatch
                 elif not equal_a and not equal_b:
                     yield b'conflict', iz, zmatch, ia, amatch, ib, bmatch
                 else:
                     raise AssertionError(b"can't handle a=b=base but unmatched")
 
                 ia = amatch
                 ib = bmatch
             iz = zmatch
 
             # if the same part of the base was deleted on both sides
             # that's OK, we can just skip it.
 
             if matchlen > 0:
                 assert ia == amatch
                 assert ib == bmatch
                 assert iz == zmatch
 
                 yield b'unchanged', zmatch, zend
                 iz = zend
                 ia = aend
                 ib = bend
 
     def minimize(self, merge_regions):
         """Trim conflict regions of lines where A and B sides match.
 
         Lines where both A and B have made the same changes at the beginning
         or the end of each merge region are eliminated from the conflict
         region and are instead considered the same.
         """
         for region in merge_regions:
             if region[0] != b"conflict":
                 yield region
                 continue
             # pytype thinks this tuple contains only 3 things, but
             # that's clearly not true because this code successfully
             # executes. It might be wise to rework merge_regions to be
             # some kind of attrs type.
             (
                 issue,
                 z1,
                 z2,
                 a1,
                 a2,
                 b1,
                 b2,
             ) = region  # pytype: disable=bad-unpacking
             alen = a2 - a1
             blen = b2 - b1
 
             # find matches at the front
             ii = 0
             while (
                 ii < alen and ii < blen and self.a[a1 + ii] == self.b[b1 + ii]
             ):
                 ii += 1
             startmatches = ii
 
             # find matches at the end
             ii = 0
             while (
                 ii < alen
                 and ii < blen
                 and self.a[a2 - ii - 1] == self.b[b2 - ii - 1]
             ):
                 ii += 1
             endmatches = ii
 
             if startmatches > 0:
                 yield b'same', a1, a1 + startmatches
 
             yield (
                 b'conflict',
                 z1,
                 z2,
                 a1 + startmatches,
                 a2 - endmatches,
                 b1 + startmatches,
                 b2 - endmatches,
             )
 
             if endmatches > 0:
                 yield b'same', a2 - endmatches, a2
 
     def find_sync_regions(self):
         """Return a list of sync regions, where both descendants match the base.
 
         Generates a list of (base1, base2, a1, a2, b1, b2).  There is
         always a zero-length sync region at the end of all the files.
         """
 
         ia = ib = 0
         amatches = mdiff.get_matching_blocks(self.basetext, self.atext)
         bmatches = mdiff.get_matching_blocks(self.basetext, self.btext)
         len_a = len(amatches)
         len_b = len(bmatches)
 
         sl = []
 
         while ia < len_a and ib < len_b:
             abase, amatch, alen = amatches[ia]
             bbase, bmatch, blen = bmatches[ib]
 
             # there is an unconflicted block at i; how long does it
             # extend?  until whichever one ends earlier.
             i = intersect((abase, abase + alen), (bbase, bbase + blen))
             if i:
                 intbase = i[0]
                 intend = i[1]
                 intlen = intend - intbase
 
                 # found a match of base[i[0], i[1]]; this may be less than
                 # the region that matches in either one
                 assert intlen <= alen
                 assert intlen <= blen
                 assert abase <= intbase
                 assert bbase <= intbase
 
                 asub = amatch + (intbase - abase)
                 bsub = bmatch + (intbase - bbase)
                 aend = asub + intlen
                 bend = bsub + intlen
 
                 assert self.base[intbase:intend] == self.a[asub:aend], (
                     self.base[intbase:intend],
                     self.a[asub:aend],
                 )
 
                 assert self.base[intbase:intend] == self.b[bsub:bend]
 
                 sl.append((intbase, intend, asub, aend, bsub, bend))
 
             # advance whichever one ends first in the base text
             if (abase + alen) < (bbase + blen):
                 ia += 1
             else:
                 ib += 1
 
         intbase = len(self.base)
         abase = len(self.a)
         bbase = len(self.b)
         sl.append((intbase, intbase, abase, abase, bbase, bbase))
 
         return sl
 
     def find_unconflicted(self):
         """Return a list of ranges in base that are not conflicted."""
         am = mdiff.get_matching_blocks(self.basetext, self.atext)
         bm = mdiff.get_matching_blocks(self.basetext, self.btext)
 
         unc = []
 
         while am and bm:
             # there is an unconflicted block at i; how long does it
             # extend?  until whichever one ends earlier.
             a1 = am[0][0]
             a2 = a1 + am[0][2]
             b1 = bm[0][0]
             b2 = b1 + bm[0][2]
             i = intersect((a1, a2), (b1, b2))
             if i:
                 unc.append(i)
 
             if a2 < b2:
                 del am[0]
             else:
                 del bm[0]
 
         return unc
 
 
 def _verifytext(text, path, ui, opts):
     """verifies that text is non-binary (unless opts[text] is passed,
     then we just warn)"""
     if stringutil.binary(text):
         msg = _(b"%s looks like a binary file.") % path
         if not opts.get('quiet'):
             ui.warn(_(b'warning: %s\n') % msg)
         if not opts.get('text'):
             raise error.Abort(msg)
     return text
 
 
 def _picklabels(defaults, overrides):
     if len(overrides) > 3:
         raise error.Abort(_(b"can only specify three labels."))
     result = defaults[:]
     for i, override in enumerate(overrides):
         result[i] = override
     return result
 
 
 def is_not_null(ctx):
     if not util.safehasattr(ctx, "node"):
         return False
     return ctx.node() != nodemod.nullid
 
 
+def _mergediff(m3, name_a, name_b, name_base):
+    lines = []
+    conflicts = False
+    for group in m3.merge_groups():
+        if group[0] == b'conflict':
+            base_lines, a_lines, b_lines = group[1:]
+            base_text = b''.join(base_lines)
+            b_blocks = list(
+                mdiff.allblocks(
+                    base_text,
+                    b''.join(b_lines),
+                    lines1=base_lines,
+                    lines2=b_lines,
+                )
+            )
+            a_blocks = list(
+                mdiff.allblocks(
+                    base_text,
+                    b''.join(a_lines),
+                    lines1=base_lines,
+                    lines2=b_lines,
+                )
+            )
+
+            def matching_lines(blocks):
+                return sum(
+                    block[1] - block[0]
+                    for block, kind in blocks
+                    if kind == b'='
+                )
+
+            def diff_lines(blocks, lines1, lines2):
+                for block, kind in blocks:
+                    if kind == b'=':
+                        for line in lines1[block[0] : block[1]]:
+                            yield b' ' + line
+                    else:
+                        for line in lines1[block[0] : block[1]]:
+                            yield b'-' + line
+                        for line in lines2[block[2] : block[3]]:
+                            yield b'+' + line
+
+            lines.append(b"<<<<<<<\n")
+            if matching_lines(a_blocks) < matching_lines(b_blocks):
+                lines.append(b"======= %s\n" % name_a)
+                lines.extend(a_lines)
+                lines.append(b"------- %s\n" % name_base)
+                lines.append(b"+++++++ %s\n" % name_b)
+                lines.extend(diff_lines(b_blocks, base_lines, b_lines))
+            else:
+                lines.append(b"------- %s\n" % name_base)
+                lines.append(b"+++++++ %s\n" % name_a)
+                lines.extend(diff_lines(a_blocks, base_lines, a_lines))
+                lines.append(b"======= %s\n" % name_b)
+                lines.extend(b_lines)
+            lines.append(b">>>>>>>\n")
+            conflicts = True
+        else:
+            lines.extend(group[1])
+    return lines, conflicts
+
+
 def simplemerge(ui, localctx, basectx, otherctx, **opts):
     """Performs the simplemerge algorithm.
 
     The merged result is written into `localctx`.
     """
 
     def readctx(ctx):
         # Merges were always run in the working copy before, which means
         # they used decoded data, if the user defined any repository
         # filters.
         #
         # Maintain that behavior today for BC, though perhaps in the future
         # it'd be worth considering whether merging encoded data (what the
         # repository usually sees) might be more useful.
         return _verifytext(ctx.decodeddata(), ctx.path(), ui, opts)
 
     mode = opts.get('mode', b'merge')
     name_a, name_b, name_base = None, None, None
     if mode != b'union':
         name_a, name_b, name_base = _picklabels(
             [localctx.path(), otherctx.path(), None], opts.get('label', [])
         )
 
     try:
         localtext = readctx(localctx)
         basetext = readctx(basectx)
         othertext = readctx(otherctx)
     except error.Abort:
         return 1
 
     m3 = Merge3Text(basetext, localtext, othertext)
     extrakwargs = {
         b"localorother": opts.get("localorother", None),
         b'minimize': True,
     }
     if mode == b'union':
         extrakwargs[b'start_marker'] = None
         extrakwargs[b'mid_marker'] = None
         extrakwargs[b'end_marker'] = None
     elif name_base is not None:
         extrakwargs[b'base_marker'] = b'|||||||'
         extrakwargs[b'name_base'] = name_base
         extrakwargs[b'minimize'] = False
 
-    lines = m3.merge_lines(
-        name_a=name_a, name_b=name_b, **pycompat.strkwargs(extrakwargs)
-    )
+    if mode == b'mergediff':
+        lines, conflicts = _mergediff(m3, name_a, name_b, name_base)
+    else:
+        lines = list(
+            m3.merge_lines(
+                name_a=name_a, name_b=name_b, **pycompat.strkwargs(extrakwargs)
+            )
+        )
+        conflicts = m3.conflicts
 
     # merge flags if necessary
     flags = localctx.flags()
     localflags = set(pycompat.iterbytestr(flags))
     otherflags = set(pycompat.iterbytestr(otherctx.flags()))
     if is_not_null(basectx) and localflags != otherflags:
         baseflags = set(pycompat.iterbytestr(basectx.flags()))
         commonflags = localflags & otherflags
         addedflags = (localflags ^ otherflags) - baseflags
         flags = b''.join(sorted(commonflags | addedflags))
 
     mergedtext = b''.join(lines)
     if opts.get('print'):
         ui.fout.write(mergedtext)
     else:
         localctx.write(mergedtext, flags)
 
-    if m3.conflicts and not mode == b'union':
+    if conflicts and not mode == b'union':
         return 1

relnotes/next

@@ -1,49 +1,56 b''
 == New Features ==
 
  * There is a new config section for templates used by hg commands. It
    is called `[command-templates]`. Some existing config options have
    been deprecated in favor of config options in the new
    section. These are: `ui.logtemplate` to `command-templates.log`,
    `ui.graphnodetemplate` to `command-templates.graphnode`,
    `ui.mergemarkertemplate` to `command-templates.mergemarker`,
    `ui.pre-merge-tool-output-template` to
    `command-templates.pre-merge-tool-output`.
 
  * There is a new set of config options for the template used for the
    one-line commit summary displayed by various commands, such as `hg
    rebase`. The main one is `command-templates.oneline-summary`. That
    can be overridden per command with
    `command-templates.oneline-summary.<command>`, where `<command>`
    can be e.g. `rebase`. As part of this effort, the default format
    from `hg rebase` was reorganized a bit.
 
  * `hg strip`, from the strip extension, is now a core command, `hg
    debugstrip`. The extension remains for compatibility.
 
  * `hg diff` now supports `--from <rev>` and `--to <rev>` arguments as
    clearer alternatives to `-r <revs>`. `-r <revs>` has been
    deprecated.
 
  * The memory footprint per changeset during pull/unbundle
    operations has been further reduced.
 
+ * There is a new internal merge tool called `internal:mergediff` (can
+   be set as the value for the `merge` config in the `[ui]`
+   section). It resolves merges the same was as `internal:merge` and
+   `internal:merge3`, but it shows conflicts differently. Instead of
+   showing 2 or 3 snapshots of the conflicting pieces of code, it
+   shows one snapshot and a diff. This may be useful when at least one
+   side of the conflict is similar to the base.
 
 == New Experimental Features ==
 
 * `experimental.single-head-per-branch:public-changes-only` can be used
   restrict the single head check to public revision. This is useful for
   overlay repository that have both a publishing and non-publishing view
   of the same storage.
 
 
 == Bug Fixes ==
 
 
 
 == Backwards Compatibility Changes ==
 
 
 
 == Internal API Changes ==
 
 

tests/test-conflict.t

@@ -1,348 +1,422 b''
   $ hg init
   $ cat << EOF > a
   > Small Mathematical Series.
   > One
   > Two
   > Three
   > Four
   > Five
   > Hop we are done.
   > EOF
   $ hg add a
   $ hg commit -m ancestor
   $ cat << EOF > a
   > Small Mathematical Series.
   > 1
   > 2
   > 3
   > 4
   > 5
   > Hop we are done.
   > EOF
   $ hg commit -m branch1
   $ hg co 0
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ cat << EOF > a
   > Small Mathematical Series.
   > 1
   > 2
   > 3
   > 6
   > 8
   > Hop we are done.
   > EOF
   $ hg commit -m branch2
   created new head
 
   $ hg merge 1
   merging a
   warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
   0 files updated, 0 files merged, 0 files removed, 1 files unresolved
   use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
   [1]
 
   $ hg id
   618808747361+c0c68e4fe667+ tip
 
   $ echo "[commands]" >> $HGRCPATH
   $ echo "status.verbose=true" >> $HGRCPATH
   $ hg status
   M a
   ? a.orig
   # The repository is in an unfinished *merge* state.
   
   # Unresolved merge conflicts:
   # 
   #     a
   # 
   # To mark files as resolved:  hg resolve --mark FILE
   
   # To continue:    hg commit
   # To abort:       hg merge --abort
   
   $ hg status -Tjson
   [
    {
     "itemtype": "file",
     "path": "a",
     "status": "M",
     "unresolved": true
    },
    {
     "itemtype": "file",
     "path": "a.orig",
     "status": "?"
    },
    {
     "itemtype": "morestatus",
     "unfinished": "merge",
     "unfinishedmsg": "To continue:    hg commit\nTo abort:       hg merge --abort"
    }
   ]
 
   $ hg status -0
   M a\x00? a.orig\x00 (no-eol) (esc)
   $ cat a
   Small Mathematical Series.
   1
   2
   3
   <<<<<<< working copy: 618808747361 - test: branch2
   6
   8
   =======
   4
   5
   >>>>>>> merge rev:    c0c68e4fe667 - test: branch1
   Hop we are done.
 
   $ hg status --config commands.status.verbose=0
   M a
   ? a.orig
 
 Verify custom conflict markers
 
   $ hg up -q --clean .
   $ cat <<EOF >> .hg/hgrc
   > [command-templates]
   > mergemarker = '{author} {rev}'
   > EOF
 
   $ hg merge 1
   merging a
   warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
   0 files updated, 0 files merged, 0 files removed, 1 files unresolved
   use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
   [1]
 
   $ cat a
   Small Mathematical Series.
   1
   2
   3
   <<<<<<< working copy: test 2
   6
   8
   =======
   4
   5
   >>>>>>> merge rev:    test 1
   Hop we are done.
 
 Verify custom conflict markers with legacy config name
 
   $ hg up -q --clean .
   $ cat <<EOF >> .hg/hgrc
   > [ui]
   > mergemarkertemplate = '{author} {rev}'
   > EOF
 
   $ hg merge 1
   merging a
   warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
   0 files updated, 0 files merged, 0 files removed, 1 files unresolved
   use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
   [1]
 
   $ cat a
   Small Mathematical Series.
   1
   2
   3
   <<<<<<< working copy: test 2
   6
   8
   =======
   4
   5
   >>>>>>> merge rev:    test 1
   Hop we are done.
 
 Verify line splitting of custom conflict marker which causes multiple lines
 
   $ hg up -q --clean .
   $ cat >> .hg/hgrc <<EOF
   > [command-templates]
   > mergemarker={author} {rev}\nfoo\nbar\nbaz
   > EOF
 
   $ hg -q merge 1
   warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
   [1]
 
   $ cat a
   Small Mathematical Series.
   1
   2
   3
   <<<<<<< working copy: test 2
   6
   8
   =======
   4
   5
   >>>>>>> merge rev:    test 1
   Hop we are done.
 
 Verify line trimming of custom conflict marker using multi-byte characters
 
   $ hg up -q --clean .
   $ "$PYTHON" <<EOF
   > fp = open('logfile', 'wb')
   > fp.write(b'12345678901234567890123456789012345678901234567890' +
   >          b'1234567890') # there are 5 more columns for 80 columns
   > 
   > # 2 x 4 = 8 columns, but 3 x 4 = 12 bytes
   > fp.write(u'\u3042\u3044\u3046\u3048'.encode('utf-8'))
   > 
   > fp.close()
   > EOF
   $ hg add logfile
   $ hg --encoding utf-8 commit --logfile logfile
 
   $ cat >> .hg/hgrc <<EOF
   > [command-templates]
   > mergemarker={desc|firstline}
   > EOF
 
   $ hg -q --encoding utf-8 merge 1
   warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
   [1]
 
   $ cat a
   Small Mathematical Series.
   1
   2
   3
   <<<<<<< working copy: 1234567890123456789012345678901234567890123456789012345...
   6
   8
   =======
   4
   5
   >>>>>>> merge rev:    branch1
   Hop we are done.
 
 Verify basic conflict markers
 
   $ hg up -q --clean 2
   $ printf "\n[ui]\nmergemarkers=basic\n" >> .hg/hgrc
 
   $ hg merge 1
   merging a
   warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
   0 files updated, 0 files merged, 0 files removed, 1 files unresolved
   use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
   [1]
 
   $ cat a
   Small Mathematical Series.
   1
   2
   3
   <<<<<<< working copy
   6
   8
   =======
   4
   5
   >>>>>>> merge rev
   Hop we are done.
 
 internal:merge3
 
   $ hg up -q --clean .
 
   $ hg merge 1 --tool internal:merge3
   merging a
   warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
   0 files updated, 0 files merged, 0 files removed, 1 files unresolved
   use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
   [1]
   $ cat a
   Small Mathematical Series.
   <<<<<<< working copy
   1
   2
   3
   6
   8
   ||||||| base
   One
   Two
   Three
   Four
   Five
   =======
   1
   2
   3
   4
   5
   >>>>>>> merge rev
   Hop we are done.
 
+internal:mergediff
+
+  $ hg co -C 1
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ cat << EOF > a
+  > Small Mathematical Series.
+  > 1
+  > 2
+  > 3
+  > 4
+  > 4.5
+  > 5
+  > Hop we are done.
+  > EOF
+  $ hg co -m 2 -t internal:mergediff
+  merging a
+  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
+  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
+  use 'hg resolve' to retry unresolved file merges
+  [1]
+  $ cat a
+  Small Mathematical Series.
+  1
+  2
+  3
+  <<<<<<<
+  ------- base
+  +++++++ working copy
+   4
+  +4.5
+   5
+  ======= destination
+  6
+  8
+  >>>>>>>
+  Hop we are done.
+Test the same thing as above but modify a bit more so we instead get the working
+copy in full and the diff from base to destination.
+  $ hg co -C 1
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ cat << EOF > a
+  > Small Mathematical Series.
+  > 1
+  > 2
+  > 3.5
+  > 4.5
+  > 5.5
+  > Hop we are done.
+  > EOF
+  $ hg co -m 2 -t internal:mergediff
+  merging a
+  warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
+  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
+  use 'hg resolve' to retry unresolved file merges
+  [1]
+  $ cat a
+  Small Mathematical Series.
+  1
+  2
+  <<<<<<<
+  ======= working copy
+  3.5
+  4.5
+  5.5
+  ------- base
+  +++++++ destination
+   3
+  -4
+  -5
+  +6
+  +8
+  >>>>>>>
+  Hop we are done.
+
 Add some unconflicting changes on each head, to make sure we really
 are merging, unlike :local and :other
 
   $ hg up -C
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   updated to "e0693e20f496: 123456789012345678901234567890123456789012345678901234567890????"
   1 other heads for branch "default"
   $ printf "\n\nEnd of file\n" >> a
   $ hg ci -m "Add some stuff at the end"
   $ hg up -r 1
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ printf "Start of file\n\n\n" > tmp
   $ cat a >> tmp
   $ mv tmp a
   $ hg ci -m "Add some stuff at the beginning"
 
 Now test :merge-other and :merge-local
 
   $ hg merge
   merging a
   warning: conflicts while merging a! (edit, then use 'hg resolve --mark')
   1 files updated, 0 files merged, 0 files removed, 1 files unresolved
   use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
   [1]
   $ hg resolve --tool :merge-other a
   merging a
   (no more unresolved files)
   $ cat a
   Start of file
   
   
   Small Mathematical Series.
   1
   2
   3
   6
   8
   Hop we are done.
   
   
   End of file
 
   $ hg up -C
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   updated to "18b51d585961: Add some stuff at the beginning"
   1 other heads for branch "default"
   $ hg merge --tool :merge-local
   merging a
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ cat a
   Start of file
   
   
   Small Mathematical Series.
   1
   2
   3
   4
   5
   Hop we are done.
   
   
   End of file

tests/test-help.t

@@ -1,3924 +1,3931 b''
 Short help:
 
   $ hg
   Mercurial Distributed SCM
   
   basic commands:
   
    add           add the specified files on the next commit
    annotate      show changeset information by line for each file
    clone         make a copy of an existing repository
    commit        commit the specified files or all outstanding changes
    diff          diff repository (or selected files)
    export        dump the header and diffs for one or more changesets
    forget        forget the specified files on the next commit
    init          create a new repository in the given directory
    log           show revision history of entire repository or files
    merge         merge another revision into working directory
    pull          pull changes from the specified source
    push          push changes to the specified destination
    remove        remove the specified files on the next commit
    serve         start stand-alone webserver
    status        show changed files in the working directory
    summary       summarize working directory state
    update        update working directory (or switch revisions)
   
   (use 'hg help' for the full list of commands or 'hg -v' for details)
 
   $ hg -q
    add           add the specified files on the next commit
    annotate      show changeset information by line for each file
    clone         make a copy of an existing repository
    commit        commit the specified files or all outstanding changes
    diff          diff repository (or selected files)
    export        dump the header and diffs for one or more changesets
    forget        forget the specified files on the next commit
    init          create a new repository in the given directory
    log           show revision history of entire repository or files
    merge         merge another revision into working directory
    pull          pull changes from the specified source
    push          push changes to the specified destination
    remove        remove the specified files on the next commit
    serve         start stand-alone webserver
    status        show changed files in the working directory
    summary       summarize working directory state
    update        update working directory (or switch revisions)
 
 Extra extensions will be printed in help output in a non-reliable order since
 the extension is unknown.
 #if no-extraextensions
 
   $ hg help
   Mercurial Distributed SCM
   
   list of commands:
   
   Repository creation:
   
    clone         make a copy of an existing repository
    init          create a new repository in the given directory
   
   Remote repository management:
   
    incoming      show new changesets found in source
    outgoing      show changesets not found in the destination
    paths         show aliases for remote repositories
    pull          pull changes from the specified source
    push          push changes to the specified destination
    serve         start stand-alone webserver
   
   Change creation:
   
    commit        commit the specified files or all outstanding changes
   
   Change manipulation:
   
    backout       reverse effect of earlier changeset
    graft         copy changes from other branches onto the current branch
    merge         merge another revision into working directory
   
   Change organization:
   
    bookmarks     create a new bookmark or list existing bookmarks
    branch        set or show the current branch name
    branches      list repository named branches
    phase         set or show the current phase name
    tag           add one or more tags for the current or given revision
    tags          list repository tags
   
   File content management:
   
    annotate      show changeset information by line for each file
    cat           output the current or given revision of files
    copy          mark files as copied for the next commit
    diff          diff repository (or selected files)
    grep          search for a pattern in specified files
   
   Change navigation:
   
    bisect        subdivision search of changesets
    heads         show branch heads
    identify      identify the working directory or specified revision
    log           show revision history of entire repository or files
   
   Working directory management:
   
    add           add the specified files on the next commit
    addremove     add all new files, delete all missing files
    files         list tracked files
    forget        forget the specified files on the next commit
    remove        remove the specified files on the next commit
    rename        rename files; equivalent of copy + remove
    resolve       redo merges or set/view the merge status of files
    revert        restore files to their checkout state
    root          print the root (top) of the current working directory
    shelve        save and set aside changes from the working directory
    status        show changed files in the working directory
    summary       summarize working directory state
    unshelve      restore a shelved change to the working directory
    update        update working directory (or switch revisions)
   
   Change import/export:
   
    archive       create an unversioned archive of a repository revision
    bundle        create a bundle file
    export        dump the header and diffs for one or more changesets
    import        import an ordered set of patches
    unbundle      apply one or more bundle files
   
   Repository maintenance:
   
    manifest      output the current or given revision of the project manifest
    recover       roll back an interrupted transaction
    verify        verify the integrity of the repository
   
   Help:
   
    config        show combined config settings from all hgrc files
    help          show help for a given topic or a help overview
    version       output version and copyright information
   
   additional help topics:
   
   Mercurial identifiers:
   
    filesets      Specifying File Sets
    hgignore      Syntax for Mercurial Ignore Files
    patterns      File Name Patterns
    revisions     Specifying Revisions
    urls          URL Paths
   
   Mercurial output:
   
    color         Colorizing Outputs
    dates         Date Formats
    diffs         Diff Formats
    templating    Template Usage
   
   Mercurial configuration:
   
    config        Configuration Files
    environment   Environment Variables
    extensions    Using Additional Features
    flags         Command-line flags
    hgweb         Configuring hgweb
    merge-tools   Merge Tools
    pager         Pager Support
   
   Concepts:
   
    bundlespec    Bundle File Formats
    glossary      Glossary
    phases        Working with Phases
    subrepos      Subrepositories
   
   Miscellaneous:
   
    deprecated    Deprecated Features
    internals     Technical implementation topics
    scripting     Using Mercurial from scripts and automation
   
   (use 'hg help -v' to show built-in aliases and global options)
 
   $ hg -q help
   Repository creation:
   
    clone         make a copy of an existing repository
    init          create a new repository in the given directory
   
   Remote repository management:
   
    incoming      show new changesets found in source
    outgoing      show changesets not found in the destination
    paths         show aliases for remote repositories
    pull          pull changes from the specified source
    push          push changes to the specified destination
    serve         start stand-alone webserver
   
   Change creation:
   
    commit        commit the specified files or all outstanding changes
   
   Change manipulation:
   
    backout       reverse effect of earlier changeset
    graft         copy changes from other branches onto the current branch
    merge         merge another revision into working directory
   
   Change organization:
   
    bookmarks     create a new bookmark or list existing bookmarks
    branch        set or show the current branch name
    branches      list repository named branches
    phase         set or show the current phase name
    tag           add one or more tags for the current or given revision
    tags          list repository tags
   
   File content management:
   
    annotate      show changeset information by line for each file
    cat           output the current or given revision of files
    copy          mark files as copied for the next commit
    diff          diff repository (or selected files)
    grep          search for a pattern in specified files
   
   Change navigation:
   
    bisect        subdivision search of changesets
    heads         show branch heads
    identify      identify the working directory or specified revision
    log           show revision history of entire repository or files
   
   Working directory management:
   
    add           add the specified files on the next commit
    addremove     add all new files, delete all missing files
    files         list tracked files
    forget        forget the specified files on the next commit
    remove        remove the specified files on the next commit
    rename        rename files; equivalent of copy + remove
    resolve       redo merges or set/view the merge status of files
    revert        restore files to their checkout state
    root          print the root (top) of the current working directory
    shelve        save and set aside changes from the working directory
    status        show changed files in the working directory
    summary       summarize working directory state
    unshelve      restore a shelved change to the working directory
    update        update working directory (or switch revisions)
   
   Change import/export:
   
    archive       create an unversioned archive of a repository revision
    bundle        create a bundle file
    export        dump the header and diffs for one or more changesets
    import        import an ordered set of patches
    unbundle      apply one or more bundle files
   
   Repository maintenance:
   
    manifest      output the current or given revision of the project manifest
    recover       roll back an interrupted transaction
    verify        verify the integrity of the repository
   
   Help:
   
    config        show combined config settings from all hgrc files
    help          show help for a given topic or a help overview
    version       output version and copyright information
   
   additional help topics:
   
   Mercurial identifiers:
   
    filesets      Specifying File Sets
    hgignore      Syntax for Mercurial Ignore Files
    patterns      File Name Patterns
    revisions     Specifying Revisions
    urls          URL Paths
   
   Mercurial output:
   
    color         Colorizing Outputs
    dates         Date Formats
    diffs         Diff Formats
    templating    Template Usage
   
   Mercurial configuration:
   
    config        Configuration Files
    environment   Environment Variables
    extensions    Using Additional Features
    flags         Command-line flags
    hgweb         Configuring hgweb
    merge-tools   Merge Tools
    pager         Pager Support
   
   Concepts:
   
    bundlespec    Bundle File Formats
    glossary      Glossary
    phases        Working with Phases
    subrepos      Subrepositories
   
   Miscellaneous:
   
    deprecated    Deprecated Features
    internals     Technical implementation topics
    scripting     Using Mercurial from scripts and automation
 
 Test extension help:
   $ hg help extensions --config extensions.rebase= --config extensions.children=
   Using Additional Features
   """""""""""""""""""""""""
   
       Mercurial has the ability to add new features through the use of
       extensions. Extensions may add new commands, add options to existing
       commands, change the default behavior of commands, or implement hooks.
   
       To enable the "foo" extension, either shipped with Mercurial or in the
       Python search path, create an entry for it in your configuration file,
       like this:
   
         [extensions]
         foo =
   
       You may also specify the full path to an extension:
   
         [extensions]
         myfeature = ~/.hgext/myfeature.py
   
       See 'hg help config' for more information on configuration files.
   
       Extensions are not loaded by default for a variety of reasons: they can
       increase startup overhead; they may be meant for advanced usage only; they
       may provide potentially dangerous abilities (such as letting you destroy
       or modify history); they might not be ready for prime time; or they may
       alter some usual behaviors of stock Mercurial. It is thus up to the user
       to activate extensions as needed.
   
       To explicitly disable an extension enabled in a configuration file of
       broader scope, prepend its path with !:
   
         [extensions]
         # disabling extension bar residing in /path/to/extension/bar.py
         bar = !/path/to/extension/bar.py
         # ditto, but no path was supplied for extension baz
         baz = !
   
       enabled extensions:
   
        children      command to display child changesets (DEPRECATED)
        rebase        command to move sets of revisions to a different ancestor
   
       disabled extensions:
   
        acl           hooks for controlling repository access
        blackbox      log repository events to a blackbox for debugging
        bugzilla      hooks for integrating with the Bugzilla bug tracker
        censor        erase file content at a given revision
        churn         command to display statistics about repository history
        clonebundles  advertise pre-generated bundles to seed clones
        closehead     close arbitrary heads without checking them out first
        convert       import revisions from foreign VCS repositories into
                      Mercurial
        eol           automatically manage newlines in repository files
        extdiff       command to allow external programs to compare revisions
        factotum      http authentication with factotum
        fastexport    export repositories as git fast-import stream
        githelp       try mapping git commands to Mercurial commands
        gpg           commands to sign and verify changesets
        hgk           browse the repository in a graphical way
        highlight     syntax highlighting for hgweb (requires Pygments)
        histedit      interactive history editing
        keyword       expand keywords in tracked files
        largefiles    track large binary files
        mq            manage a stack of patches
        notify        hooks for sending email push notifications
        patchbomb     command to send changesets as (a series of) patch emails
        purge         command to delete untracked files from the working
                      directory
        relink        recreates hardlinks between repository clones
        schemes       extend schemes with shortcuts to repository swarms
        share         share a common history between several working directories
        transplant    command to transplant changesets from another branch
        win32mbcs     allow the use of MBCS paths with problematic encodings
        zeroconf      discover and advertise repositories on the local network
 
 #endif
 
 Verify that deprecated extensions are included if --verbose:
 
   $ hg -v help extensions | grep children
        children      command to display child changesets (DEPRECATED)
 
 Verify that extension keywords appear in help templates
 
   $ hg help --config extensions.transplant= templating|grep transplant > /dev/null
 
 Test short command list with verbose option
 
   $ hg -v help shortlist
   Mercurial Distributed SCM
   
   basic commands:
   
    abort         abort an unfinished operation (EXPERIMENTAL)
    add           add the specified files on the next commit
    annotate, blame
                  show changeset information by line for each file
    clone         make a copy of an existing repository
    commit, ci    commit the specified files or all outstanding changes
    continue      resumes an interrupted operation (EXPERIMENTAL)
    diff          diff repository (or selected files)
    export        dump the header and diffs for one or more changesets
    forget        forget the specified files on the next commit
    init          create a new repository in the given directory
    log, history  show revision history of entire repository or files
    merge         merge another revision into working directory
    pull          pull changes from the specified source
    push          push changes to the specified destination
    remove, rm    remove the specified files on the next commit
    serve         start stand-alone webserver
    status, st    show changed files in the working directory
    summary, sum  summarize working directory state
    update, up, checkout, co
                  update working directory (or switch revisions)
   
   global options ([+] can be repeated):
   
    -R --repository REPO   repository root directory or name of overlay bundle
                           file
       --cwd DIR           change working directory
    -y --noninteractive    do not prompt, automatically pick the first choice for
                           all prompts
    -q --quiet             suppress output
    -v --verbose           enable additional output
       --color TYPE        when to colorize (boolean, always, auto, never, or
                           debug)
       --config CONFIG [+] set/override config option (use 'section.name=value')
       --debug             enable debugging output
       --debugger          start debugger
       --encoding ENCODE   set the charset encoding (default: ascii)
       --encodingmode MODE set the charset encoding mode (default: strict)
       --traceback         always print a traceback on exception
       --time              time how long the command takes
       --profile           print command execution profile
       --version           output version information and exit
    -h --help              display help and exit
       --hidden            consider hidden changesets
       --pager TYPE        when to paginate (boolean, always, auto, or never)
                           (default: auto)
   
   (use 'hg help' for the full list of commands)
 
   $ hg add -h
   hg add [OPTION]... [FILE]...
   
   add the specified files on the next commit
   
       Schedule files to be version controlled and added to the repository.
   
       The files will be added to the repository at the next commit. To undo an
       add before that, see 'hg forget'.
   
       If no names are given, add all files to the repository (except files
       matching ".hgignore").
   
       Returns 0 if all files are successfully added.
   
   options ([+] can be repeated):
   
    -I --include PATTERN [+] include names matching the given patterns
    -X --exclude PATTERN [+] exclude names matching the given patterns
    -S --subrepos            recurse into subrepositories
    -n --dry-run             do not perform actions, just print output
   
   (some details hidden, use --verbose to show complete help)
 
 Verbose help for add
 
   $ hg add -hv
   hg add [OPTION]... [FILE]...
   
   add the specified files on the next commit
   
       Schedule files to be version controlled and added to the repository.
   
       The files will be added to the repository at the next commit. To undo an
       add before that, see 'hg forget'.
   
       If no names are given, add all files to the repository (except files
       matching ".hgignore").
   
       Examples:
   
         - New (unknown) files are added automatically by 'hg add':
   
             $ ls
             foo.c
             $ hg status
             ? foo.c
             $ hg add
             adding foo.c
             $ hg status
             A foo.c
   
         - Specific files to be added can be specified:
   
             $ ls
             bar.c  foo.c
             $ hg status
             ? bar.c
             ? foo.c
             $ hg add bar.c
             $ hg status
             A bar.c
             ? foo.c
   
       Returns 0 if all files are successfully added.
   
   options ([+] can be repeated):
   
    -I --include PATTERN [+] include names matching the given patterns
    -X --exclude PATTERN [+] exclude names matching the given patterns
    -S --subrepos            recurse into subrepositories
    -n --dry-run             do not perform actions, just print output
   
   global options ([+] can be repeated):
   
    -R --repository REPO   repository root directory or name of overlay bundle
                           file
       --cwd DIR           change working directory
    -y --noninteractive    do not prompt, automatically pick the first choice for
                           all prompts
    -q --quiet             suppress output
    -v --verbose           enable additional output
       --color TYPE        when to colorize (boolean, always, auto, never, or
                           debug)
       --config CONFIG [+] set/override config option (use 'section.name=value')
       --debug             enable debugging output
       --debugger          start debugger
       --encoding ENCODE   set the charset encoding (default: ascii)
       --encodingmode MODE set the charset encoding mode (default: strict)
       --traceback         always print a traceback on exception
       --time              time how long the command takes
       --profile           print command execution profile
       --version           output version information and exit
    -h --help              display help and exit
       --hidden            consider hidden changesets
       --pager TYPE        when to paginate (boolean, always, auto, or never)
                           (default: auto)
 
 Test the textwidth config option
 
   $ hg root -h  --config ui.textwidth=50
   hg root
   
   print the root (top) of the current working
   directory
   
       Print the root directory of the current
       repository.
   
       Returns 0 on success.
   
   options:
   
    -T --template TEMPLATE display with template
   
   (some details hidden, use --verbose to show
   complete help)
 
 Test help option with version option
 
   $ hg add -h --version
   Mercurial Distributed SCM (version *) (glob)
   (see https://mercurial-scm.org for more information)
   
   Copyright (C) 2005-* Matt Mackall and others (glob)
   This is free software; see the source for copying conditions. There is NO
   warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 
   $ hg add --skjdfks
   hg add: option --skjdfks not recognized
   hg add [OPTION]... [FILE]...
   
   add the specified files on the next commit
   
   options ([+] can be repeated):
   
    -I --include PATTERN [+] include names matching the given patterns
    -X --exclude PATTERN [+] exclude names matching the given patterns
    -S --subrepos            recurse into subrepositories
    -n --dry-run             do not perform actions, just print output
   
   (use 'hg add -h' to show more help)
   [255]
 
 Test ambiguous command help
 
   $ hg help ad
   list of commands:
   
    add           add the specified files on the next commit
    addremove     add all new files, delete all missing files
   
   (use 'hg help -v ad' to show built-in aliases and global options)
 
 Test command without options
 
   $ hg help verify
   hg verify
   
   verify the integrity of the repository
   
       Verify the integrity of the current repository.
   
       This will perform an extensive check of the repository's integrity,
       validating the hashes and checksums of each entry in the changelog,
       manifest, and tracked files, as well as the integrity of their crosslinks
       and indices.
   
       Please see https://mercurial-scm.org/wiki/RepositoryCorruption for more
       information about recovery from corruption of the repository.
   
       Returns 0 on success, 1 if errors are encountered.
   
   options:
   
   (some details hidden, use --verbose to show complete help)
 
   $ hg help diff
   hg diff [OPTION]... ([-c REV] | [--from REV1] [--to REV2]) [FILE]...
   
   diff repository (or selected files)
   
       Show differences between revisions for the specified files.
   
       Differences between files are shown using the unified diff format.
   
       Note:
          'hg diff' may generate unexpected results for merges, as it will
          default to comparing against the working directory's first parent
          changeset if no revisions are specified.
   
       By default, the working directory files are compared to its first parent.
       To see the differences from another revision, use --from. To see the
       difference to another revision, use --to. For example, 'hg diff --from .^'
       will show the differences from the working copy's grandparent to the
       working copy, 'hg diff --to .' will show the diff from the working copy to
       its parent (i.e. the reverse of the default), and 'hg diff --from 1.0 --to
       1.2' will show the diff between those two revisions.
   
       Alternatively you can specify -c/--change with a revision to see the
       changes in that changeset relative to its first parent (i.e. 'hg diff -c
       42' is equivalent to 'hg diff --from 42^ --to 42')
   
       Without the -a/--text option, diff will avoid generating diffs of files it
       detects as binary. With -a, diff will generate a diff anyway, probably
       with undesirable results.
   
       Use the -g/--git option to generate diffs in the git extended diff format.
       For more information, read 'hg help diffs'.
   
       Returns 0 on success.
   
   options ([+] can be repeated):
   
       --from REV1           revision to diff from
       --to REV2             revision to diff to
    -c --change REV          change made by revision
    -a --text                treat all files as text
    -g --git                 use git extended diff format
       --binary              generate binary diffs in git mode (default)
       --nodates             omit dates from diff headers
       --noprefix            omit a/ and b/ prefixes from filenames
    -p --show-function       show which function each change is in
       --reverse             produce a diff that undoes the changes
    -w --ignore-all-space    ignore white space when comparing lines
    -b --ignore-space-change ignore changes in the amount of white space
    -B --ignore-blank-lines  ignore changes whose lines are all blank
    -Z --ignore-space-at-eol ignore changes in whitespace at EOL
    -U --unified NUM         number of lines of context to show
       --stat                output diffstat-style summary of changes
       --root DIR            produce diffs relative to subdirectory
    -I --include PATTERN [+] include names matching the given patterns
    -X --exclude PATTERN [+] exclude names matching the given patterns
    -S --subrepos            recurse into subrepositories
   
   (some details hidden, use --verbose to show complete help)
 
   $ hg help status
   hg status [OPTION]... [FILE]...
   
   aliases: st
   
   show changed files in the working directory
   
       Show status of files in the repository. If names are given, only files
       that match are shown. Files that are clean or ignored or the source of a
       copy/move operation, are not listed unless -c/--clean, -i/--ignored,
       -C/--copies or -A/--all are given. Unless options described with "show
       only ..." are given, the options -mardu are used.
   
       Option -q/--quiet hides untracked (unknown and ignored) files unless
       explicitly requested with -u/--unknown or -i/--ignored.
   
       Note:
          'hg status' may appear to disagree with diff if permissions have
          changed or a merge has occurred. The standard diff format does not
          report permission changes and diff only reports changes relative to one
          merge parent.
   
       If one revision is given, it is used as the base revision. If two
       revisions are given, the differences between them are shown. The --change
       option can also be used as a shortcut to list the changed files of a
       revision from its first parent.
   
       The codes used to show the status of files are:
   
         M = modified
         A = added
         R = removed
         C = clean
         ! = missing (deleted by non-hg command, but still tracked)
         ? = not tracked
         I = ignored
           = origin of the previous file (with --copies)
   
       Returns 0 on success.
   
   options ([+] can be repeated):
   
    -A --all                 show status of all files
    -m --modified            show only modified files
    -a --added               show only added files
    -r --removed             show only removed files
    -d --deleted             show only missing files
    -c --clean               show only files without changes
    -u --unknown             show only unknown (not tracked) files
    -i --ignored             show only ignored files
    -n --no-status           hide status prefix
    -C --copies              show source of copied files
    -0 --print0              end filenames with NUL, for use with xargs
       --rev REV [+]         show difference from revision
       --change REV          list the changed files of a revision
    -I --include PATTERN [+] include names matching the given patterns
    -X --exclude PATTERN [+] exclude names matching the given patterns
    -S --subrepos            recurse into subrepositories
    -T --template TEMPLATE   display with template
   
   (some details hidden, use --verbose to show complete help)
 
   $ hg -q help status
   hg status [OPTION]... [FILE]...
   
   show changed files in the working directory
 
   $ hg help foo
   abort: no such help topic: foo
   (try 'hg help --keyword foo')
   [255]
 
   $ hg skjdfks
   hg: unknown command 'skjdfks'
   (use 'hg help' for a list of commands)
   [255]
 
 Typoed command gives suggestion
   $ hg puls
   hg: unknown command 'puls'
   (did you mean one of pull, push?)
   [255]
 
 Not enabled extension gets suggested
 
   $ hg rebase
   hg: unknown command 'rebase'
   'rebase' is provided by the following extension:
   
       rebase        command to move sets of revisions to a different ancestor
   
   (use 'hg help extensions' for information on enabling extensions)
   [255]
 
 Disabled extension gets suggested
   $ hg --config extensions.rebase=! rebase
   hg: unknown command 'rebase'
   'rebase' is provided by the following extension:
   
       rebase        command to move sets of revisions to a different ancestor
   
   (use 'hg help extensions' for information on enabling extensions)
   [255]
 
 Checking that help adapts based on the config:
 
   $ hg help diff --config ui.tweakdefaults=true | egrep -e '^ *(-g|config)'
    -g --[no-]git            use git extended diff format (default: on from
                             config)
 
 Make sure that we don't run afoul of the help system thinking that
 this is a section and erroring out weirdly.
 
   $ hg .log
   hg: unknown command '.log'
   (did you mean log?)
   [255]
 
   $ hg log.
   hg: unknown command 'log.'
   (did you mean log?)
   [255]
   $ hg pu.lh
   hg: unknown command 'pu.lh'
   (did you mean one of pull, push?)
   [255]
 
   $ cat > helpext.py <<EOF
   > import os
   > from mercurial import commands, fancyopts, registrar
   > 
   > def func(arg):
   >     return '%sfoo' % arg
   > class customopt(fancyopts.customopt):
   >     def newstate(self, oldstate, newparam, abort):
   >         return '%sbar' % oldstate
   > cmdtable = {}
   > command = registrar.command(cmdtable)
   > 
   > @command(b'nohelp',
   >     [(b'', b'longdesc', 3, b'x'*67),
   >     (b'n', b'', None, b'normal desc'),
   >     (b'', b'newline', b'', b'line1\nline2'),
   >     (b'', b'default-off', False, b'enable X'),
   >     (b'', b'default-on', True, b'enable Y'),
   >     (b'', b'callableopt', func, b'adds foo'),
   >     (b'', b'customopt', customopt(''), b'adds bar'),
   >     (b'', b'customopt-withdefault', customopt('foo'), b'adds bar')],
   >     b'hg nohelp',
   >     norepo=True)
   > @command(b'debugoptADV', [(b'', b'aopt', None, b'option is (ADVANCED)')])
   > @command(b'debugoptDEP', [(b'', b'dopt', None, b'option is (DEPRECATED)')])
   > @command(b'debugoptEXP', [(b'', b'eopt', None, b'option is (EXPERIMENTAL)')])
   > def nohelp(ui, *args, **kwargs):
   >     pass
   > 
   > @command(b'hashelp', [], b'hg hashelp', norepo=True)
   > def hashelp(ui, *args, **kwargs):
   >     """Extension command's help"""
   > 
   > def uisetup(ui):
   >     ui.setconfig(b'alias', b'shellalias', b'!echo hi', b'helpext')
   >     ui.setconfig(b'alias', b'hgalias', b'summary', b'helpext')
   >     ui.setconfig(b'alias', b'hgalias:doc', b'My doc', b'helpext')
   >     ui.setconfig(b'alias', b'hgalias:category', b'navigation', b'helpext')
   >     ui.setconfig(b'alias', b'hgaliasnodoc', b'summary', b'helpext')
   > 
   > EOF
   $ echo '[extensions]' >> $HGRCPATH
   $ echo "helpext = `pwd`/helpext.py" >> $HGRCPATH
 
 Test for aliases
 
   $ hg help | grep hgalias
    hgalias       My doc
 
   $ hg help hgalias
   hg hgalias [--remote]
   
   alias for: hg summary
   
   My doc
   
   defined by: helpext
   
   options:
   
     --remote check for push and pull
   
   (some details hidden, use --verbose to show complete help)
   $ hg help hgaliasnodoc
   hg hgaliasnodoc [--remote]
   
   alias for: hg summary
   
   summarize working directory state
   
       This generates a brief summary of the working directory state, including
       parents, branch, commit status, phase and available updates.
   
       With the --remote option, this will check the default paths for incoming
       and outgoing changes. This can be time-consuming.
   
       Returns 0 on success.
   
   defined by: helpext
   
   options:
   
     --remote check for push and pull
   
   (some details hidden, use --verbose to show complete help)
 
   $ hg help shellalias
   hg shellalias
   
   shell alias for: echo hi
   
   (no help text available)
   
   defined by: helpext
   
   (some details hidden, use --verbose to show complete help)
 
 Test command with no help text
 
   $ hg help nohelp
   hg nohelp
   
   (no help text available)
   
   options:
   
       --longdesc VALUE
                                     xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
                                     xxxxxxxxxxxxxxxxxxxxxxx (default: 3)
    -n --                            normal desc
       --newline VALUE               line1 line2
       --default-off                 enable X
       --[no-]default-on             enable Y (default: on)
       --callableopt VALUE           adds foo
       --customopt VALUE             adds bar
       --customopt-withdefault VALUE adds bar (default: foo)
   
   (some details hidden, use --verbose to show complete help)
 
 Test that default list of commands includes extension commands that have help,
 but not those that don't, except in verbose mode, when a keyword is passed, or
 when help about the extension is requested.
 
 #if no-extraextensions
 
   $ hg help | grep hashelp
    hashelp       Extension command's help
   $ hg help | grep nohelp
   [1]
   $ hg help -v | grep nohelp
    nohelp        (no help text available)
 
   $ hg help -k nohelp
   Commands:
   
    nohelp hg nohelp
   
   Extension Commands:
   
    nohelp (no help text available)
 
   $ hg help helpext
   helpext extension - no help text available
   
   list of commands:
   
    hashelp       Extension command's help
    nohelp        (no help text available)
   
   (use 'hg help -v helpext' to show built-in aliases and global options)
 
 #endif
 
 Test list of internal help commands
 
   $ hg help debug
   debug commands (internal and unsupported):
   
    debugancestor
                  find the ancestor revision of two revisions in a given index
    debugantivirusrunning
                  attempt to trigger an antivirus scanner to see if one is active
    debugapplystreamclonebundle
                  apply a stream clone bundle file
    debugbackupbundle
                  lists the changesets available in backup bundles
    debugbuilddag
                  builds a repo with a given DAG from scratch in the current
                  empty repo
    debugbundle   lists the contents of a bundle
    debugcapabilities
                  lists the capabilities of a remote peer
    debugchangedfiles
                  list the stored files changes for a revision
    debugcheckstate
                  validate the correctness of the current dirstate
    debugcolor    show available color, effects or style
    debugcommands
                  list all available commands and options
    debugcomplete
                  returns the completion list associated with the given command
    debugcreatestreamclonebundle
                  create a stream clone bundle file
    debugdag      format the changelog or an index DAG as a concise textual
                  description
    debugdata     dump the contents of a data file revision
    debugdate     parse and display a date
    debugdeltachain
                  dump information about delta chains in a revlog
    debugdirstate
                  show the contents of the current dirstate
    debugdiscovery
                  runs the changeset discovery protocol in isolation
    debugdownload
                  download a resource using Mercurial logic and config
    debugextensions
                  show information about active extensions
    debugfileset  parse and apply a fileset specification
    debugformat   display format information about the current repository
    debugfsinfo   show information detected about current filesystem
    debuggetbundle
                  retrieves a bundle from a repo
    debugignore   display the combined ignore pattern and information about
                  ignored files
    debugindex    dump index data for a storage primitive
    debugindexdot
                  dump an index DAG as a graphviz dot file
    debugindexstats
                  show stats related to the changelog index
    debuginstall  test Mercurial installation
    debugknown    test whether node ids are known to a repo
    debuglocks    show or modify state of locks
    debugmanifestfulltextcache
                  show, clear or amend the contents of the manifest fulltext
                  cache
    debugmergestate
                  print merge state
    debugnamecomplete
                  complete "names" - tags, open branch names, bookmark names
    debugnodemap  write and inspect on disk nodemap
    debugobsolete
                  create arbitrary obsolete marker
    debugoptADV   (no help text available)
    debugoptDEP   (no help text available)
    debugoptEXP   (no help text available)
    debugp1copies
                  dump copy information compared to p1
    debugp2copies
                  dump copy information compared to p2
    debugpathcomplete
                  complete part or all of a tracked path
    debugpathcopies
                  show copies between two revisions
    debugpeer     establish a connection to a peer repository
    debugpickmergetool
                  examine which merge tool is chosen for specified file
    debugpushkey  access the pushkey key/value protocol
    debugpvec     (no help text available)
    debugrebuilddirstate
                  rebuild the dirstate as it would look like for the given
                  revision
    debugrebuildfncache
                  rebuild the fncache file
    debugrename   dump rename information
    debugrequires
                  print the current repo requirements
    debugrevlog   show data and statistics about a revlog
    debugrevlogindex
                  dump the contents of a revlog index
    debugrevspec  parse and apply a revision specification
    debugserve    run a server with advanced settings
    debugsetparents
                  manually set the parents of the current working directory
    debugsidedata
                  dump the side data for a cl/manifest/file revision
    debugssl      test a secure connection to a server
    debugstrip    strip changesets and all their descendants from the repository
    debugsub      (no help text available)
    debugsuccessorssets
                  show set of successors for revision
    debugtagscache
                  display the contents of .hg/cache/hgtagsfnodes1
    debugtemplate
                  parse and apply a template
    debuguigetpass
                  show prompt to type password
    debuguiprompt
                  show plain prompt
    debugupdatecaches
                  warm all known caches in the repository
    debugupgraderepo
                  upgrade a repository to use different features
    debugwalk     show how files match on given patterns
    debugwhyunstable
                  explain instabilities of a changeset
    debugwireargs
                  (no help text available)
    debugwireproto
                  send wire protocol commands to a server
   
   (use 'hg help -v debug' to show built-in aliases and global options)
 
 internals topic renders index of available sub-topics
 
   $ hg help internals
   Technical implementation topics
   """""""""""""""""""""""""""""""
   
       To access a subtopic, use "hg help internals.{subtopic-name}"
   
        bid-merge     Bid Merge Algorithm
        bundle2       Bundle2
        bundles       Bundles
        cbor          CBOR
        censor        Censor
        changegroups  Changegroups
        config        Config Registrar
        extensions    Extension API
        mergestate    Mergestate
        requirements  Repository Requirements
        revlogs       Revision Logs
        wireprotocol  Wire Protocol
        wireprotocolrpc
                      Wire Protocol RPC
        wireprotocolv2
                      Wire Protocol Version 2
 
 sub-topics can be accessed
 
   $ hg help internals.changegroups
   Changegroups
   """"""""""""
   
       Changegroups are representations of repository revlog data, specifically
       the changelog data, root/flat manifest data, treemanifest data, and
       filelogs.
   
       There are 3 versions of changegroups: "1", "2", and "3". From a high-
       level, versions "1" and "2" are almost exactly the same, with the only
       difference being an additional item in the *delta header*. Version "3"
       adds support for storage flags in the *delta header* and optionally
       exchanging treemanifests (enabled by setting an option on the
       "changegroup" part in the bundle2).
   
       Changegroups when not exchanging treemanifests consist of 3 logical
       segments:
   
         +---------------------------------+
         |           |          |          |
         | changeset | manifest | filelogs |
         |           |          |          |
         |           |          |          |
         +---------------------------------+
   
       When exchanging treemanifests, there are 4 logical segments:
   
         +-------------------------------------------------+
         |           |          |               |          |
         | changeset |   root   | treemanifests | filelogs |
         |           | manifest |               |          |
         |           |          |               |          |
         +-------------------------------------------------+
   
       The principle building block of each segment is a *chunk*. A *chunk* is a
       framed piece of data:
   
         +---------------------------------------+
         |           |                           |
         |  length   |           data            |
         | (4 bytes) |   (<length - 4> bytes)    |
         |           |                           |
         +---------------------------------------+
   
       All integers are big-endian signed integers. Each chunk starts with a
       32-bit integer indicating the length of the entire chunk (including the
       length field itself).
   
       There is a special case chunk that has a value of 0 for the length
       ("0x00000000"). We call this an *empty chunk*.
   
       Delta Groups
       ============
   
       A *delta group* expresses the content of a revlog as a series of deltas,
       or patches against previous revisions.
   
       Delta groups consist of 0 or more *chunks* followed by the *empty chunk*
       to signal the end of the delta group:
   
         +------------------------------------------------------------------------+
         |                |             |               |             |           |
         | chunk0 length  | chunk0 data | chunk1 length | chunk1 data |    0x0    |
         |   (4 bytes)    |  (various)  |   (4 bytes)   |  (various)  | (4 bytes) |
         |                |             |               |             |           |
         +------------------------------------------------------------------------+
   
       Each *chunk*'s data consists of the following:
   
         +---------------------------------------+
         |                        |              |
         |     delta header       |  delta data  |
         |  (various by version)  |  (various)   |
         |                        |              |
         +---------------------------------------+
   
       The *delta data* is a series of *delta*s that describe a diff from an
       existing entry (either that the recipient already has, or previously
       specified in the bundle/changegroup).
   
       The *delta header* is different between versions "1", "2", and "3" of the
       changegroup format.
   
       Version 1 (headerlen=80):
   
         +------------------------------------------------------+
         |            |             |             |             |
         |    node    |   p1 node   |   p2 node   |  link node  |
         | (20 bytes) |  (20 bytes) |  (20 bytes) |  (20 bytes) |
         |            |             |             |             |
         +------------------------------------------------------+
   
       Version 2 (headerlen=100):
   
         +------------------------------------------------------------------+
         |            |             |             |            |            |
         |    node    |   p1 node   |   p2 node   | base node  | link node  |
         | (20 bytes) |  (20 bytes) |  (20 bytes) | (20 bytes) | (20 bytes) |
         |            |             |             |            |            |
         +------------------------------------------------------------------+
   
       Version 3 (headerlen=102):
   
         +------------------------------------------------------------------------------+
         |            |             |             |            |            |           |
         |    node    |   p1 node   |   p2 node   | base node  | link node  |   flags   |
         | (20 bytes) |  (20 bytes) |  (20 bytes) | (20 bytes) | (20 bytes) | (2 bytes) |
         |            |             |             |            |            |           |
         +------------------------------------------------------------------------------+
   
       The *delta data* consists of "chunklen - 4 - headerlen" bytes, which
       contain a series of *delta*s, densely packed (no separators). These deltas
       describe a diff from an existing entry (either that the recipient already
       has, or previously specified in the bundle/changegroup). The format is
       described more fully in "hg help internals.bdiff", but briefly:
   
         +---------------------------------------------------------------+
         |              |            |            |                      |
         | start offset | end offset | new length |        content       |
         |  (4 bytes)   |  (4 bytes) |  (4 bytes) | (<new length> bytes) |
         |              |            |            |                      |
         +---------------------------------------------------------------+
   
       Please note that the length field in the delta data does *not* include
       itself.
   
       In version 1, the delta is always applied against the previous node from
       the changegroup or the first parent if this is the first entry in the
       changegroup.
   
       In version 2 and up, the delta base node is encoded in the entry in the
       changegroup. This allows the delta to be expressed against any parent,
       which can result in smaller deltas and more efficient encoding of data.
   
       The *flags* field holds bitwise flags affecting the processing of revision
       data. The following flags are defined:
   
       32768
          Censored revision. The revision's fulltext has been replaced by censor
          metadata. May only occur on file revisions.
   
       16384
          Ellipsis revision. Revision hash does not match data (likely due to
          rewritten parents).
   
       8192
          Externally stored. The revision fulltext contains "key:value" "\n"
          delimited metadata defining an object stored elsewhere. Used by the LFS
          extension.
   
       For historical reasons, the integer values are identical to revlog version
       1 per-revision storage flags and correspond to bits being set in this
       2-byte field. Bits were allocated starting from the most-significant bit,
       hence the reverse ordering and allocation of these flags.
   
       Changeset Segment
       =================
   
       The *changeset segment* consists of a single *delta group* holding
       changelog data. The *empty chunk* at the end of the *delta group* denotes
       the boundary to the *manifest segment*.
   
       Manifest Segment
       ================
   
       The *manifest segment* consists of a single *delta group* holding manifest
       data. If treemanifests are in use, it contains only the manifest for the
       root directory of the repository. Otherwise, it contains the entire
       manifest data. The *empty chunk* at the end of the *delta group* denotes
       the boundary to the next segment (either the *treemanifests segment* or
       the *filelogs segment*, depending on version and the request options).
   
       Treemanifests Segment
       ---------------------
   
       The *treemanifests segment* only exists in changegroup version "3", and
       only if the 'treemanifest' param is part of the bundle2 changegroup part
       (it is not possible to use changegroup version 3 outside of bundle2).
       Aside from the filenames in the *treemanifests segment* containing a
       trailing "/" character, it behaves identically to the *filelogs segment*
       (see below). The final sub-segment is followed by an *empty chunk*
       (logically, a sub-segment with filename size 0). This denotes the boundary
       to the *filelogs segment*.
   
       Filelogs Segment
       ================
   
       The *filelogs segment* consists of multiple sub-segments, each
       corresponding to an individual file whose data is being described:
   
         +--------------------------------------------------+
         |          |          |          |     |           |
         | filelog0 | filelog1 | filelog2 | ... |    0x0    |
         |          |          |          |     | (4 bytes) |
         |          |          |          |     |           |
         +--------------------------------------------------+
   
       The final filelog sub-segment is followed by an *empty chunk* (logically,
       a sub-segment with filename size 0). This denotes the end of the segment
       and of the overall changegroup.
   
       Each filelog sub-segment consists of the following:
   
         +------------------------------------------------------+
         |                 |                      |             |
         | filename length |       filename       | delta group |
         |    (4 bytes)    | (<length - 4> bytes) |  (various)  |
         |                 |                      |             |
         +------------------------------------------------------+
   
       That is, a *chunk* consisting of the filename (not terminated or padded)
       followed by N chunks constituting the *delta group* for this file. The
       *empty chunk* at the end of each *delta group* denotes the boundary to the
       next filelog sub-segment.
 
 non-existent subtopics print an error
 
   $ hg help internals.foo
   abort: no such help topic: internals.foo
   (try 'hg help --keyword foo')
   [255]
 
 test advanced, deprecated and experimental options are hidden in command help
   $ hg help debugoptADV
   hg debugoptADV
   
   (no help text available)
   
   options:
   
   (some details hidden, use --verbose to show complete help)
   $ hg help debugoptDEP
   hg debugoptDEP
   
   (no help text available)
   
   options:
   
   (some details hidden, use --verbose to show complete help)
 
   $ hg help debugoptEXP
   hg debugoptEXP
   
   (no help text available)
   
   options:
   
   (some details hidden, use --verbose to show complete help)
 
 test advanced, deprecated and experimental options are shown with -v
   $ hg help -v debugoptADV | grep aopt
     --aopt option is (ADVANCED)
   $ hg help -v debugoptDEP | grep dopt
     --dopt option is (DEPRECATED)
   $ hg help -v debugoptEXP | grep eopt
     --eopt option is (EXPERIMENTAL)
 
 #if gettext
 test deprecated option is hidden with translation with untranslated description
 (use many globy for not failing on changed transaction)
   $ LANGUAGE=sv hg help debugoptDEP
   hg debugoptDEP
   
   (*) (glob)
   
   options:
   
   (some details hidden, use --verbose to show complete help)
 #endif
 
 Test commands that collide with topics (issue4240)
 
   $ hg config -hq
   hg config [-u] [NAME]...
   
   show combined config settings from all hgrc files
   $ hg showconfig -hq
   hg config [-u] [NAME]...
   
   show combined config settings from all hgrc files
 
 Test a help topic
 
   $ hg help dates
   Date Formats
   """"""""""""
   
       Some commands allow the user to specify a date, e.g.:
   
       - backout, commit, import, tag: Specify the commit date.
       - log, revert, update: Select revision(s) by date.
   
       Many date formats are valid. Here are some examples:
   
       - "Wed Dec 6 13:18:29 2006" (local timezone assumed)
       - "Dec 6 13:18 -0600" (year assumed, time offset provided)
       - "Dec 6 13:18 UTC" (UTC and GMT are aliases for +0000)
       - "Dec 6" (midnight)
       - "13:18" (today assumed)
       - "3:39" (3:39AM assumed)
       - "3:39pm" (15:39)
       - "2006-12-06 13:18:29" (ISO 8601 format)
       - "2006-12-6 13:18"
       - "2006-12-6"
       - "12-6"
       - "12/6"
       - "12/6/6" (Dec 6 2006)
       - "today" (midnight)
       - "yesterday" (midnight)
       - "now" - right now
   
       Lastly, there is Mercurial's internal format:
   
       - "1165411109 0" (Wed Dec 6 13:18:29 2006 UTC)
   
       This is the internal representation format for dates. The first number is
       the number of seconds since the epoch (1970-01-01 00:00 UTC). The second
       is the offset of the local timezone, in seconds west of UTC (negative if
       the timezone is east of UTC).
   
       The log command also accepts date ranges:
   
       - "<DATE" - at or before a given date/time
       - ">DATE" - on or after a given date/time
       - "DATE to DATE" - a date range, inclusive
       - "-DAYS" - within a given number of days from today
 
 Test repeated config section name
 
   $ hg help config.host
       "http_proxy.host"
           Host name and (optional) port of the proxy server, for example
           "myproxy:8000".
   
       "smtp.host"
           Host name of mail server, e.g. "mail.example.com".
   
 
 Test section name with dot
 
   $ hg help config.ui.username
       "ui.username"
           The committer of a changeset created when running "commit". Typically
           a person's name and email address, e.g. "Fred Widget
           <[e-mail]>". Environment variables in the username are
           expanded.
   
           (default: "$EMAIL" or "username@hostname". If the username in hgrc is
           empty, e.g. if the system admin set "username =" in the system hgrc,
           it has to be specified manually or in a different hgrc file)
   
 
   $ hg help config.annotate.git
   abort: help section not found: config.annotate.git
   [255]
 
   $ hg help config.update.check
       "commands.update.check"
           Determines what level of checking 'hg update' will perform before
           moving to a destination revision. Valid values are "abort", "none",
           "linear", and "noconflict". "abort" always fails if the working
           directory has uncommitted changes. "none" performs no checking, and
           may result in a merge with uncommitted changes. "linear" allows any
           update as long as it follows a straight line in the revision history,
           and may trigger a merge with uncommitted changes. "noconflict" will
           allow any update which would not trigger a merge with uncommitted
           changes, if any are present. (default: "linear")
   
 
   $ hg help config.commands.update.check
       "commands.update.check"
           Determines what level of checking 'hg update' will perform before
           moving to a destination revision. Valid values are "abort", "none",
           "linear", and "noconflict". "abort" always fails if the working
           directory has uncommitted changes. "none" performs no checking, and
           may result in a merge with uncommitted changes. "linear" allows any
           update as long as it follows a straight line in the revision history,
           and may trigger a merge with uncommitted changes. "noconflict" will
           allow any update which would not trigger a merge with uncommitted
           changes, if any are present. (default: "linear")
   
 
   $ hg help config.ommands.update.check
   abort: help section not found: config.ommands.update.check
   [255]
 
 Unrelated trailing paragraphs shouldn't be included
 
   $ hg help config.extramsg | grep '^$'
   
 
 Test capitalized section name
 
   $ hg help scripting.HGPLAIN > /dev/null
 
 Help subsection:
 
   $ hg help config.charsets |grep "Email example:" > /dev/null
   [1]
 
 Show nested definitions
 ("profiling.type"[break]"ls"[break]"stat"[break])
 
   $ hg help config.type | egrep '^$'|wc -l
   \s*3 (re)
 
   $ hg help config.profiling.type.ls
           "profiling.type.ls"
             Use Python's built-in instrumenting profiler. This profiler works on
             all platforms, but each line number it reports is the first line of
             a function. This restriction makes it difficult to identify the
             expensive parts of a non-trivial function.
   
 
 Separate sections from subsections
 
   $ hg help config.format | egrep '^    ("|-)|^\s*$' | uniq
       "format"
       --------
   
       "usegeneraldelta"
   
       "dotencode"
   
       "usefncache"
   
       "usestore"
   
       "sparse-revlog"
   
       "revlog-compression"
   
       "bookmarks-in-store"
   
       "profiling"
       -----------
   
       "format"
   
       "progress"
       ----------
   
       "format"
   
 
 Last item in help config.*:
 
   $ hg help config.`hg help config|grep '^    "'| \
   >       tail -1|sed 's![ "]*!!g'`| \
   >   grep 'hg help -c config' > /dev/null
   [1]
 
 note to use help -c for general hg help config:
 
   $ hg help config |grep 'hg help -c config' > /dev/null
 
 Test templating help
 
   $ hg help templating | egrep '(desc|diffstat|firstline|nonempty)  '
       desc          String. The text of the changeset description.
       diffstat      String. Statistics of changes with the following format:
       firstline     Any text. Returns the first line of text.
       nonempty      Any text. Returns '(none)' if the string is empty.
 
 Test deprecated items
 
   $ hg help -v templating | grep currentbookmark
       currentbookmark
   $ hg help templating | (grep currentbookmark || true)
 
 Test help hooks
 
   $ cat > helphook1.py <<EOF
   > from mercurial import help
   > 
   > def rewrite(ui, topic, doc):
   >     return doc + b'\nhelphook1\n'
   > 
   > def extsetup(ui):
   >     help.addtopichook(b'revisions', rewrite)
   > EOF
   $ cat > helphook2.py <<EOF
   > from mercurial import help
   > 
   > def rewrite(ui, topic, doc):
   >     return doc + b'\nhelphook2\n'
   > 
   > def extsetup(ui):
   >     help.addtopichook(b'revisions', rewrite)
   > EOF
   $ echo '[extensions]' >> $HGRCPATH
   $ echo "helphook1 = `pwd`/helphook1.py" >> $HGRCPATH
   $ echo "helphook2 = `pwd`/helphook2.py" >> $HGRCPATH
   $ hg help revsets | grep helphook
       helphook1
       helphook2
 
 help -c should only show debug --debug
 
   $ hg help -c --debug|egrep debug|wc -l|egrep '^\s*0\s*$'
   [1]
 
 help -c should only show deprecated for -v
 
   $ hg help -c -v|egrep DEPRECATED|wc -l|egrep '^\s*0\s*$'
   [1]
 
 Test -s / --system
 
   $ hg help config.files -s windows |grep 'etc/mercurial' | \
   > wc -l | sed -e 's/ //g'
   0
   $ hg help config.files --system unix | grep 'USER' | \
   > wc -l | sed -e 's/ //g'
   0
 
 Test -e / -c / -k combinations
 
   $ hg help -c|egrep '^[A-Z].*:|^ debug'
   Commands:
   $ hg help -e|egrep '^[A-Z].*:|^ debug'
   Extensions:
   $ hg help -k|egrep '^[A-Z].*:|^ debug'
   Topics:
   Commands:
   Extensions:
   Extension Commands:
   $ hg help -c schemes
   abort: no such help topic: schemes
   (try 'hg help --keyword schemes')
   [255]
   $ hg help -e schemes |head -1
   schemes extension - extend schemes with shortcuts to repository swarms
   $ hg help -c -k dates |egrep '^(Topics|Extensions|Commands):'
   Commands:
   $ hg help -e -k a |egrep '^(Topics|Extensions|Commands):'
   Extensions:
   $ hg help -e -c -k date |egrep '^(Topics|Extensions|Commands):'
   Extensions:
   Commands:
   $ hg help -c commit > /dev/null
   $ hg help -e -c commit > /dev/null
   $ hg help -e commit
   abort: no such help topic: commit
   (try 'hg help --keyword commit')
   [255]
 
 Test keyword search help
 
   $ cat > prefixedname.py <<EOF
   > '''matched against word "clone"
   > '''
   > EOF
   $ echo '[extensions]' >> $HGRCPATH
   $ echo "dot.dot.prefixedname = `pwd`/prefixedname.py" >> $HGRCPATH
   $ hg help -k clone
   Topics:
   
    config     Configuration Files
    extensions Using Additional Features
    glossary   Glossary
    phases     Working with Phases
    subrepos   Subrepositories
    urls       URL Paths
   
   Commands:
   
    bookmarks create a new bookmark or list existing bookmarks
    clone     make a copy of an existing repository
    paths     show aliases for remote repositories
    pull      pull changes from the specified source
    update    update working directory (or switch revisions)
   
   Extensions:
   
    clonebundles advertise pre-generated bundles to seed clones
    narrow       create clones which fetch history data for subset of files
                 (EXPERIMENTAL)
    prefixedname matched against word "clone"
    relink       recreates hardlinks between repository clones
   
   Extension Commands:
   
    qclone clone main and patch repository at same time
 
 Test unfound topic
 
   $ hg help nonexistingtopicthatwillneverexisteverever
   abort: no such help topic: nonexistingtopicthatwillneverexisteverever
   (try 'hg help --keyword nonexistingtopicthatwillneverexisteverever')
   [255]
 
 Test unfound keyword
 
   $ hg help --keyword nonexistingwordthatwillneverexisteverever
   abort: no matches
   (try 'hg help' for a list of topics)
   [255]
 
 Test omit indicating for help
 
   $ cat > addverboseitems.py <<EOF
   > r'''extension to test omit indicating.
   > 
   > This paragraph is never omitted (for extension)
   > 
   > .. container:: verbose
   > 
   >   This paragraph is omitted,
   >   if :hg:\`help\` is invoked without \`\`-v\`\` (for extension)
   > 
   > This paragraph is never omitted, too (for extension)
   > '''
   > from __future__ import absolute_import
   > from mercurial import commands, help
   > testtopic = br"""This paragraph is never omitted (for topic).
   > 
   > .. container:: verbose
   > 
   >   This paragraph is omitted,
   >   if :hg:\`help\` is invoked without \`\`-v\`\` (for topic)
   > 
   > This paragraph is never omitted, too (for topic)
   > """
   > def extsetup(ui):
   >     help.helptable.append(([b"topic-containing-verbose"],
   >                            b"This is the topic to test omit indicating.",
   >                            lambda ui: testtopic))
   > EOF
   $ echo '[extensions]' >> $HGRCPATH
   $ echo "addverboseitems = `pwd`/addverboseitems.py" >> $HGRCPATH
   $ hg help addverboseitems
   addverboseitems extension - extension to test omit indicating.
   
   This paragraph is never omitted (for extension)
   
   This paragraph is never omitted, too (for extension)
   
   (some details hidden, use --verbose to show complete help)
   
   no commands defined
   $ hg help -v addverboseitems
   addverboseitems extension - extension to test omit indicating.
   
   This paragraph is never omitted (for extension)
   
   This paragraph is omitted, if 'hg help' is invoked without "-v" (for
   extension)
   
   This paragraph is never omitted, too (for extension)
   
   no commands defined
   $ hg help topic-containing-verbose
   This is the topic to test omit indicating.
   """"""""""""""""""""""""""""""""""""""""""
   
       This paragraph is never omitted (for topic).
   
       This paragraph is never omitted, too (for topic)
   
   (some details hidden, use --verbose to show complete help)
   $ hg help -v topic-containing-verbose
   This is the topic to test omit indicating.
   """"""""""""""""""""""""""""""""""""""""""
   
       This paragraph is never omitted (for topic).
   
       This paragraph is omitted, if 'hg help' is invoked without "-v" (for
       topic)
   
       This paragraph is never omitted, too (for topic)
 
 Test section lookup
 
   $ hg help revset.merge
       "merge()"
         Changeset is a merge changeset.
   
   $ hg help glossary.dag
       DAG
           The repository of changesets of a distributed version control system
           (DVCS) can be described as a directed acyclic graph (DAG), consisting
           of nodes and edges, where nodes correspond to changesets and edges
           imply a parent -> child relation. This graph can be visualized by
           graphical tools such as 'hg log --graph'. In Mercurial, the DAG is
           limited by the requirement for children to have at most two parents.
   
 
   $ hg help hgrc.paths
       "paths"
       -------
   
       Assigns symbolic names and behavior to repositories.
   
       Options are symbolic names defining the URL or directory that is the
       location of the repository. Example:
   
         [paths]
         my_server = https://example.com/my_repo
         local_path = /home/me/repo
   
       These symbolic names can be used from the command line. To pull from
       "my_server": 'hg pull my_server'. To push to "local_path": 'hg push
       local_path'.
   
       Options containing colons (":") denote sub-options that can influence
       behavior for that specific path. Example:
   
         [paths]
         my_server = https://example.com/my_path
         my_server:pushurl = ssh://example.com/my_path
   
       The following sub-options can be defined:
   
       "pushurl"
          The URL to use for push operations. If not defined, the location
          defined by the path's main entry is used.
   
       "pushrev"
          A revset defining which revisions to push by default.
   
          When 'hg push' is executed without a "-r" argument, the revset defined
          by this sub-option is evaluated to determine what to push.
   
          For example, a value of "." will push the working directory's revision
          by default.
   
          Revsets specifying bookmarks will not result in the bookmark being
          pushed.
   
       The following special named paths exist:
   
       "default"
          The URL or directory to use when no source or remote is specified.
   
          'hg clone' will automatically define this path to the location the
          repository was cloned from.
   
       "default-push"
          (deprecated) The URL or directory for the default 'hg push' location.
          "default:pushurl" should be used instead.
   
   $ hg help glossary.mcguffin
   abort: help section not found: glossary.mcguffin
   [255]
 
   $ hg help glossary.mc.guffin
   abort: help section not found: glossary.mc.guffin
   [255]
 
   $ hg help template.files
       files         List of strings. All files modified, added, or removed by
                     this changeset.
       files(pattern)
                     All files of the current changeset matching the pattern. See
                     'hg help patterns'.
 
 Test section lookup by translated message
 
 str.lower() instead of encoding.lower(str) on translated message might
 make message meaningless, because some encoding uses 0x41(A) - 0x5a(Z)
 as the second or later byte of multi-byte character.
 
 For example, "\x8bL\x98^" (translation of "record" in ja_JP.cp932)
 contains 0x4c (L). str.lower() replaces 0x4c(L) by 0x6c(l) and this
 replacement makes message meaningless.
 
 This tests that section lookup by translated string isn't broken by
 such str.lower().
 
   $ "$PYTHON" <<EOF
   > def escape(s):
   >     return b''.join(b'\\u%x' % ord(uc) for uc in s.decode('cp932'))
   > # translation of "record" in ja_JP.cp932
   > upper = b"\x8bL\x98^"
   > # str.lower()-ed section name should be treated as different one
   > lower = b"\x8bl\x98^"
   > with open('ambiguous.py', 'wb') as fp:
   >     fp.write(b"""# ambiguous section names in ja_JP.cp932
   > u'''summary of extension
   > 
   > %s
   > ----
   > 
   > Upper name should show only this message
   > 
   > %s
   > ----
   > 
   > Lower name should show only this message
   > 
   > subsequent section
   > ------------------
   > 
   > This should be hidden at 'hg help ambiguous' with section name.
   > '''
   > """ % (escape(upper), escape(lower)))
   > EOF
 
   $ cat >> $HGRCPATH <<EOF
   > [extensions]
   > ambiguous = ./ambiguous.py
   > EOF
 
   $ "$PYTHON" <<EOF | sh
   > from mercurial.utils import procutil
   > upper = b"\x8bL\x98^"
   > procutil.stdout.write(b"hg --encoding cp932 help -e ambiguous.%s\n" % upper)
   > EOF
   \x8bL\x98^ (esc)
   ----
   
   Upper name should show only this message
   
 
   $ "$PYTHON" <<EOF | sh
   > from mercurial.utils import procutil
   > lower = b"\x8bl\x98^"
   > procutil.stdout.write(b"hg --encoding cp932 help -e ambiguous.%s\n" % lower)
   > EOF
   \x8bl\x98^ (esc)
   ----
   
   Lower name should show only this message
   
 
   $ cat >> $HGRCPATH <<EOF
   > [extensions]
   > ambiguous = !
   > EOF
 
 Show help content of disabled extensions
 
   $ cat >> $HGRCPATH <<EOF
   > [extensions]
   > ambiguous = !./ambiguous.py
   > EOF
   $ hg help -e ambiguous
   ambiguous extension - (no help text available)
   
   (use 'hg help extensions' for information on enabling extensions)
 
 Test dynamic list of merge tools only shows up once
   $ hg help merge-tools
   Merge Tools
   """""""""""
   
       To merge files Mercurial uses merge tools.
   
       A merge tool combines two different versions of a file into a merged file.
       Merge tools are given the two files and the greatest common ancestor of
       the two file versions, so they can determine the changes made on both
       branches.
   
       Merge tools are used both for 'hg resolve', 'hg merge', 'hg update', 'hg
       backout' and in several extensions.
   
       Usually, the merge tool tries to automatically reconcile the files by
       combining all non-overlapping changes that occurred separately in the two
       different evolutions of the same initial base file. Furthermore, some
       interactive merge programs make it easier to manually resolve conflicting
       merges, either in a graphical way, or by inserting some conflict markers.
       Mercurial does not include any interactive merge programs but relies on
       external tools for that.
   
       Available merge tools
       =====================
   
       External merge tools and their properties are configured in the merge-
       tools configuration section - see hgrc(5) - but they can often just be
       named by their executable.
   
       A merge tool is generally usable if its executable can be found on the
       system and if it can handle the merge. The executable is found if it is an
       absolute or relative executable path or the name of an application in the
       executable search path. The tool is assumed to be able to handle the merge
       if it can handle symlinks if the file is a symlink, if it can handle
       binary files if the file is binary, and if a GUI is available if the tool
       requires a GUI.
   
       There are some internal merge tools which can be used. The internal merge
       tools are:
   
       ":dump"
         Creates three versions of the files to merge, containing the contents of
         local, other and base. These files can then be used to perform a merge
         manually. If the file to be merged is named "a.txt", these files will
         accordingly be named "a.txt.local", "a.txt.other" and "a.txt.base" and
         they will be placed in the same directory as "a.txt".
   
         This implies premerge. Therefore, files aren't dumped, if premerge runs
         successfully. Use :forcedump to forcibly write files out.
   
         (actual capabilities: binary, symlink)
   
       ":fail"
         Rather than attempting to merge files that were modified on both
         branches, it marks them as unresolved. The resolve command must be used
         to resolve these conflicts.
   
         (actual capabilities: binary, symlink)
   
       ":forcedump"
         Creates three versions of the files as same as :dump, but omits
         premerge.
   
         (actual capabilities: binary, symlink)
   
       ":local"
         Uses the local 'p1()' version of files as the merged version.
   
         (actual capabilities: binary, symlink)
   
       ":merge"
         Uses the internal non-interactive simple merge algorithm for merging
         files. It will fail if there are any conflicts and leave markers in the
         partially merged file. Markers will have two sections, one for each side
         of merge.
   
       ":merge-local"
         Like :merge, but resolve all conflicts non-interactively in favor of the
         local 'p1()' changes.
   
       ":merge-other"
         Like :merge, but resolve all conflicts non-interactively in favor of the
         other 'p2()' changes.
   
       ":merge3"
         Uses the internal non-interactive simple merge algorithm for merging
         files. It will fail if there are any conflicts and leave markers in the
         partially merged file. Marker will have three sections, one from each
         side of the merge and one for the base content.
   
+      ":mergediff"
+        Uses the internal non-interactive simple merge algorithm for merging
+        files. It will fail if there are any conflicts and leave markers in the
+        partially merged file. The marker will have two sections, one with the
+        content from one side of the merge, and one with a diff from the base
+        content to the content on the other side. (experimental)
+  
       ":other"
         Uses the other 'p2()' version of files as the merged version.
   
         (actual capabilities: binary, symlink)
   
       ":prompt"
         Asks the user which of the local 'p1()' or the other 'p2()' version to
         keep as the merged version.
   
         (actual capabilities: binary, symlink)
   
       ":tagmerge"
         Uses the internal tag merge algorithm (experimental).
   
       ":union"
         Uses the internal non-interactive simple merge algorithm for merging
         files. It will use both left and right sides for conflict regions. No
         markers are inserted.
   
       Internal tools are always available and do not require a GUI but will by
       default not handle symlinks or binary files. See next section for detail
       about "actual capabilities" described above.
   
       Choosing a merge tool
       =====================
   
       Mercurial uses these rules when deciding which merge tool to use:
   
       1. If a tool has been specified with the --tool option to merge or
          resolve, it is used.  If it is the name of a tool in the merge-tools
          configuration, its configuration is used. Otherwise the specified tool
          must be executable by the shell.
       2. If the "HGMERGE" environment variable is present, its value is used and
          must be executable by the shell.
       3. If the filename of the file to be merged matches any of the patterns in
          the merge-patterns configuration section, the first usable merge tool
          corresponding to a matching pattern is used.
       4. If ui.merge is set it will be considered next. If the value is not the
          name of a configured tool, the specified value is used and must be
          executable by the shell. Otherwise the named tool is used if it is
          usable.
       5. If any usable merge tools are present in the merge-tools configuration
          section, the one with the highest priority is used.
       6. If a program named "hgmerge" can be found on the system, it is used -
          but it will by default not be used for symlinks and binary files.
       7. If the file to be merged is not binary and is not a symlink, then
          internal ":merge" is used.
       8. Otherwise, ":prompt" is used.
   
       For historical reason, Mercurial treats merge tools as below while
       examining rules above.
   
       step specified via  binary symlink
       ----------------------------------
       1.   --tool         o/o    o/o
       2.   HGMERGE        o/o    o/o
       3.   merge-patterns o/o(*) x/?(*)
       4.   ui.merge       x/?(*) x/?(*)
   
       Each capability column indicates Mercurial behavior for internal/external
       merge tools at examining each rule.
   
       - "o": "assume that a tool has capability"
       - "x": "assume that a tool does not have capability"
       - "?": "check actual capability of a tool"
   
       If "merge.strict-capability-check" configuration is true, Mercurial checks
       capabilities of merge tools strictly in (*) cases above (= each capability
       column becomes "?/?"). It is false by default for backward compatibility.
   
       Note:
          After selecting a merge program, Mercurial will by default attempt to
          merge the files using a simple merge algorithm first. Only if it
          doesn't succeed because of conflicting changes will Mercurial actually
          execute the merge program. Whether to use the simple merge algorithm
          first can be controlled by the premerge setting of the merge tool.
          Premerge is enabled by default unless the file is binary or a symlink.
   
       See the merge-tools and ui sections of hgrc(5) for details on the
       configuration of merge tools.
 
 Compression engines listed in `hg help bundlespec`
 
   $ hg help bundlespec | grep gzip
           "v1" bundles can only use the "gzip", "bzip2", and "none" compression
         An algorithm that produces smaller bundles than "gzip".
         This engine will likely produce smaller bundles than "gzip" but will be
       "gzip"
         better compression than "gzip". It also frequently yields better (?)
 
 Test usage of section marks in help documents
 
   $ cd "$TESTDIR"/../doc
   $ "$PYTHON" check-seclevel.py
   $ cd $TESTTMP
 
 #if serve
 
 Test the help pages in hgweb.
 
 Dish up an empty repo; serve it cold.
 
   $ hg init "$TESTTMP/test"
   $ hg serve -R "$TESTTMP/test" -n test -p $HGPORT -d --pid-file=hg.pid
   $ cat hg.pid >> $DAEMON_PIDS
 
   $ get-with-headers.py $LOCALIP:$HGPORT "help"
   200 Script output follows
   
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
   <head>
   <link rel="icon" href="/static/hgicon.png" type="image/png" />
   <meta name="robots" content="index, nofollow" />
   <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
   <script type="text/javascript" src="/static/mercurial.js"></script>
   
   <title>Help: Index</title>
   </head>
   <body>
   
   <div class="container">
   <div class="menu">
   <div class="logo">
   <a href="https://mercurial-scm.org/">
   <img src="/static/hglogo.png" alt="mercurial" /></a>
   </div>
   <ul>
   <li><a href="/shortlog">log</a></li>
   <li><a href="/graph">graph</a></li>
   <li><a href="/tags">tags</a></li>
   <li><a href="/bookmarks">bookmarks</a></li>
   <li><a href="/branches">branches</a></li>
   </ul>
   <ul>
   <li class="active">help</li>
   </ul>
   </div>
   
   <div class="main">
   <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
   
   <form class="search" action="/log">
   
   <p><input name="rev" id="search1" type="text" size="30" value="" /></p>
   <div id="hint">Find changesets by keywords (author, files, the commit message), revision
   number or hash, or <a href="/help/revsets">revset expression</a>.</div>
   </form>
   <table class="bigtable">
   <tr><td colspan="2"><h2><a name="topics" href="#topics">Topics</a></h2></td></tr>
   
   <tr><td>
   <a href="/help/bundlespec">
   bundlespec
   </a>
   </td><td>
   Bundle File Formats
   </td></tr>
   <tr><td>
   <a href="/help/color">
   color
   </a>
   </td><td>
   Colorizing Outputs
   </td></tr>
   <tr><td>
   <a href="/help/config">
   config
   </a>
   </td><td>
   Configuration Files
   </td></tr>
   <tr><td>
   <a href="/help/dates">
   dates
   </a>
   </td><td>
   Date Formats
   </td></tr>
   <tr><td>
   <a href="/help/deprecated">
   deprecated
   </a>
   </td><td>
   Deprecated Features
   </td></tr>
   <tr><td>
   <a href="/help/diffs">
   diffs
   </a>
   </td><td>
   Diff Formats
   </td></tr>
   <tr><td>
   <a href="/help/environment">
   environment
   </a>
   </td><td>
   Environment Variables
   </td></tr>
   <tr><td>
   <a href="/help/extensions">
   extensions
   </a>
   </td><td>
   Using Additional Features
   </td></tr>
   <tr><td>
   <a href="/help/filesets">
   filesets
   </a>
   </td><td>
   Specifying File Sets
   </td></tr>
   <tr><td>
   <a href="/help/flags">
   flags
   </a>
   </td><td>
   Command-line flags
   </td></tr>
   <tr><td>
   <a href="/help/glossary">
   glossary
   </a>
   </td><td>
   Glossary
   </td></tr>
   <tr><td>
   <a href="/help/hgignore">
   hgignore
   </a>
   </td><td>
   Syntax for Mercurial Ignore Files
   </td></tr>
   <tr><td>
   <a href="/help/hgweb">
   hgweb
   </a>
   </td><td>
   Configuring hgweb
   </td></tr>
   <tr><td>
   <a href="/help/internals">
   internals
   </a>
   </td><td>
   Technical implementation topics
   </td></tr>
   <tr><td>
   <a href="/help/merge-tools">
   merge-tools
   </a>
   </td><td>
   Merge Tools
   </td></tr>
   <tr><td>
   <a href="/help/pager">
   pager
   </a>
   </td><td>
   Pager Support
   </td></tr>
   <tr><td>
   <a href="/help/patterns">
   patterns
   </a>
   </td><td>
   File Name Patterns
   </td></tr>
   <tr><td>
   <a href="/help/phases">
   phases
   </a>
   </td><td>
   Working with Phases
   </td></tr>
   <tr><td>
   <a href="/help/revisions">
   revisions
   </a>
   </td><td>
   Specifying Revisions
   </td></tr>
   <tr><td>
   <a href="/help/scripting">
   scripting
   </a>
   </td><td>
   Using Mercurial from scripts and automation
   </td></tr>
   <tr><td>
   <a href="/help/subrepos">
   subrepos
   </a>
   </td><td>
   Subrepositories
   </td></tr>
   <tr><td>
   <a href="/help/templating">
   templating
   </a>
   </td><td>
   Template Usage
   </td></tr>
   <tr><td>
   <a href="/help/urls">
   urls
   </a>
   </td><td>
   URL Paths
   </td></tr>
   <tr><td>
   <a href="/help/topic-containing-verbose">
   topic-containing-verbose
   </a>
   </td><td>
   This is the topic to test omit indicating.
   </td></tr>
   
   
   <tr><td colspan="2"><h2><a name="main" href="#main">Main Commands</a></h2></td></tr>
   
   <tr><td>
   <a href="/help/abort">
   abort
   </a>
   </td><td>
   abort an unfinished operation (EXPERIMENTAL)
   </td></tr>
   <tr><td>
   <a href="/help/add">
   add
   </a>
   </td><td>
   add the specified files on the next commit
   </td></tr>
   <tr><td>
   <a href="/help/annotate">
   annotate
   </a>
   </td><td>
   show changeset information by line for each file
   </td></tr>
   <tr><td>
   <a href="/help/clone">
   clone
   </a>
   </td><td>
   make a copy of an existing repository
   </td></tr>
   <tr><td>
   <a href="/help/commit">
   commit
   </a>
   </td><td>
   commit the specified files or all outstanding changes
   </td></tr>
   <tr><td>
   <a href="/help/continue">
   continue
   </a>
   </td><td>
   resumes an interrupted operation (EXPERIMENTAL)
   </td></tr>
   <tr><td>
   <a href="/help/diff">
   diff
   </a>
   </td><td>
   diff repository (or selected files)
   </td></tr>
   <tr><td>
   <a href="/help/export">
   export
   </a>
   </td><td>
   dump the header and diffs for one or more changesets
   </td></tr>
   <tr><td>
   <a href="/help/forget">
   forget
   </a>
   </td><td>
   forget the specified files on the next commit
   </td></tr>
   <tr><td>
   <a href="/help/init">
   init
   </a>
   </td><td>
   create a new repository in the given directory
   </td></tr>
   <tr><td>
   <a href="/help/log">
   log
   </a>
   </td><td>
   show revision history of entire repository or files
   </td></tr>
   <tr><td>
   <a href="/help/merge">
   merge
   </a>
   </td><td>
   merge another revision into working directory
   </td></tr>
   <tr><td>
   <a href="/help/pull">
   pull
   </a>
   </td><td>
   pull changes from the specified source
   </td></tr>
   <tr><td>
   <a href="/help/push">
   push
   </a>
   </td><td>
   push changes to the specified destination
   </td></tr>
   <tr><td>
   <a href="/help/remove">
   remove
   </a>
   </td><td>
   remove the specified files on the next commit
   </td></tr>
   <tr><td>
   <a href="/help/serve">
   serve
   </a>
   </td><td>
   start stand-alone webserver
   </td></tr>
   <tr><td>
   <a href="/help/status">
   status
   </a>
   </td><td>
   show changed files in the working directory
   </td></tr>
   <tr><td>
   <a href="/help/summary">
   summary
   </a>
   </td><td>
   summarize working directory state
   </td></tr>
   <tr><td>
   <a href="/help/update">
   update
   </a>
   </td><td>
   update working directory (or switch revisions)
   </td></tr>
   
   
   
   <tr><td colspan="2"><h2><a name="other" href="#other">Other Commands</a></h2></td></tr>
   
   <tr><td>
   <a href="/help/addremove">
   addremove
   </a>
   </td><td>
   add all new files, delete all missing files
   </td></tr>
   <tr><td>
   <a href="/help/archive">
   archive
   </a>
   </td><td>
   create an unversioned archive of a repository revision
   </td></tr>
   <tr><td>
   <a href="/help/backout">
   backout
   </a>
   </td><td>
   reverse effect of earlier changeset
   </td></tr>
   <tr><td>
   <a href="/help/bisect">
   bisect
   </a>
   </td><td>
   subdivision search of changesets
   </td></tr>
   <tr><td>
   <a href="/help/bookmarks">
   bookmarks
   </a>
   </td><td>
   create a new bookmark or list existing bookmarks
   </td></tr>
   <tr><td>
   <a href="/help/branch">
   branch
   </a>
   </td><td>
   set or show the current branch name
   </td></tr>
   <tr><td>
   <a href="/help/branches">
   branches
   </a>
   </td><td>
   list repository named branches
   </td></tr>
   <tr><td>
   <a href="/help/bundle">
   bundle
   </a>
   </td><td>
   create a bundle file
   </td></tr>
   <tr><td>
   <a href="/help/cat">
   cat
   </a>
   </td><td>
   output the current or given revision of files
   </td></tr>
   <tr><td>
   <a href="/help/config">
   config
   </a>
   </td><td>
   show combined config settings from all hgrc files
   </td></tr>
   <tr><td>
   <a href="/help/copy">
   copy
   </a>
   </td><td>
   mark files as copied for the next commit
   </td></tr>
   <tr><td>
   <a href="/help/files">
   files
   </a>
   </td><td>
   list tracked files
   </td></tr>
   <tr><td>
   <a href="/help/graft">
   graft
   </a>
   </td><td>
   copy changes from other branches onto the current branch
   </td></tr>
   <tr><td>
   <a href="/help/grep">
   grep
   </a>
   </td><td>
   search for a pattern in specified files
   </td></tr>
   <tr><td>
   <a href="/help/hashelp">
   hashelp
   </a>
   </td><td>
   Extension command's help
   </td></tr>
   <tr><td>
   <a href="/help/heads">
   heads
   </a>
   </td><td>
   show branch heads
   </td></tr>
   <tr><td>
   <a href="/help/help">
   help
   </a>
   </td><td>
   show help for a given topic or a help overview
   </td></tr>
   <tr><td>
   <a href="/help/hgalias">
   hgalias
   </a>
   </td><td>
   My doc
   </td></tr>
   <tr><td>
   <a href="/help/hgaliasnodoc">
   hgaliasnodoc
   </a>
   </td><td>
   summarize working directory state
   </td></tr>
   <tr><td>
   <a href="/help/identify">
   identify
   </a>
   </td><td>
   identify the working directory or specified revision
   </td></tr>
   <tr><td>
   <a href="/help/import">
   import
   </a>
   </td><td>
   import an ordered set of patches
   </td></tr>
   <tr><td>
   <a href="/help/incoming">
   incoming
   </a>
   </td><td>
   show new changesets found in source
   </td></tr>
   <tr><td>
   <a href="/help/manifest">
   manifest
   </a>
   </td><td>
   output the current or given revision of the project manifest
   </td></tr>
   <tr><td>
   <a href="/help/nohelp">
   nohelp
   </a>
   </td><td>
   (no help text available)
   </td></tr>
   <tr><td>
   <a href="/help/outgoing">
   outgoing
   </a>
   </td><td>
   show changesets not found in the destination
   </td></tr>
   <tr><td>
   <a href="/help/paths">
   paths
   </a>
   </td><td>
   show aliases for remote repositories
   </td></tr>
   <tr><td>
   <a href="/help/phase">
   phase
   </a>
   </td><td>
   set or show the current phase name
   </td></tr>
   <tr><td>
   <a href="/help/recover">
   recover
   </a>
   </td><td>
   roll back an interrupted transaction
   </td></tr>
   <tr><td>
   <a href="/help/rename">
   rename
   </a>
   </td><td>
   rename files; equivalent of copy + remove
   </td></tr>
   <tr><td>
   <a href="/help/resolve">
   resolve
   </a>
   </td><td>
   redo merges or set/view the merge status of files
   </td></tr>
   <tr><td>
   <a href="/help/revert">
   revert
   </a>
   </td><td>
   restore files to their checkout state
   </td></tr>
   <tr><td>
   <a href="/help/root">
   root
   </a>
   </td><td>
   print the root (top) of the current working directory
   </td></tr>
   <tr><td>
   <a href="/help/shellalias">
   shellalias
   </a>
   </td><td>
   (no help text available)
   </td></tr>
   <tr><td>
   <a href="/help/shelve">
   shelve
   </a>
   </td><td>
   save and set aside changes from the working directory
   </td></tr>
   <tr><td>
   <a href="/help/tag">
   tag
   </a>
   </td><td>
   add one or more tags for the current or given revision
   </td></tr>
   <tr><td>
   <a href="/help/tags">
   tags
   </a>
   </td><td>
   list repository tags
   </td></tr>
   <tr><td>
   <a href="/help/unbundle">
   unbundle
   </a>
   </td><td>
   apply one or more bundle files
   </td></tr>
   <tr><td>
   <a href="/help/unshelve">
   unshelve
   </a>
   </td><td>
   restore a shelved change to the working directory
   </td></tr>
   <tr><td>
   <a href="/help/verify">
   verify
   </a>
   </td><td>
   verify the integrity of the repository
   </td></tr>
   <tr><td>
   <a href="/help/version">
   version
   </a>
   </td><td>
   output version and copyright information
   </td></tr>
   
   
   </table>
   </div>
   </div>
   
   
   
   </body>
   </html>
   
 
   $ get-with-headers.py $LOCALIP:$HGPORT "help/add"
   200 Script output follows
   
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
   <head>
   <link rel="icon" href="/static/hgicon.png" type="image/png" />
   <meta name="robots" content="index, nofollow" />
   <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
   <script type="text/javascript" src="/static/mercurial.js"></script>
   
   <title>Help: add</title>
   </head>
   <body>
   
   <div class="container">
   <div class="menu">
   <div class="logo">
   <a href="https://mercurial-scm.org/">
   <img src="/static/hglogo.png" alt="mercurial" /></a>
   </div>
   <ul>
   <li><a href="/shortlog">log</a></li>
   <li><a href="/graph">graph</a></li>
   <li><a href="/tags">tags</a></li>
   <li><a href="/bookmarks">bookmarks</a></li>
   <li><a href="/branches">branches</a></li>
   </ul>
   <ul>
    <li class="active"><a href="/help">help</a></li>
   </ul>
   </div>
   
   <div class="main">
   <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
   <h3>Help: add</h3>
   
   <form class="search" action="/log">
   
   <p><input name="rev" id="search1" type="text" size="30" value="" /></p>
   <div id="hint">Find changesets by keywords (author, files, the commit message), revision
   number or hash, or <a href="/help/revsets">revset expression</a>.</div>
   </form>
   <div id="doc">
   <p>
   hg add [OPTION]... [FILE]...
   </p>
   <p>
   add the specified files on the next commit
   </p>
   <p>
   Schedule files to be version controlled and added to the
   repository.
   </p>
   <p>
   The files will be added to the repository at the next commit. To
   undo an add before that, see 'hg forget'.
   </p>
   <p>
   If no names are given, add all files to the repository (except
   files matching &quot;.hgignore&quot;).
   </p>
   <p>
   Examples:
   </p>
   <ul>
    <li> New (unknown) files are added   automatically by 'hg add':
   <pre>
   \$ ls (re)
   foo.c
   \$ hg status (re)
   ? foo.c
   \$ hg add (re)
   adding foo.c
   \$ hg status (re)
   A foo.c
   </pre>
    <li> Specific files to be added can be specified:
   <pre>
   \$ ls (re)
   bar.c  foo.c
   \$ hg status (re)
   ? bar.c
   ? foo.c
   \$ hg add bar.c (re)
   \$ hg status (re)
   A bar.c
   ? foo.c
   </pre>
   </ul>
   <p>
   Returns 0 if all files are successfully added.
   </p>
   <p>
   options ([+] can be repeated):
   </p>
   <table>
   <tr><td>-I</td>
   <td>--include PATTERN [+]</td>
   <td>include names matching the given patterns</td></tr>
   <tr><td>-X</td>
   <td>--exclude PATTERN [+]</td>
   <td>exclude names matching the given patterns</td></tr>
   <tr><td>-S</td>
   <td>--subrepos</td>
   <td>recurse into subrepositories</td></tr>
   <tr><td>-n</td>
   <td>--dry-run</td>
   <td>do not perform actions, just print output</td></tr>
   </table>
   <p>
   global options ([+] can be repeated):
   </p>
   <table>
   <tr><td>-R</td>
   <td>--repository REPO</td>
   <td>repository root directory or name of overlay bundle file</td></tr>
   <tr><td></td>
   <td>--cwd DIR</td>
   <td>change working directory</td></tr>
   <tr><td>-y</td>
   <td>--noninteractive</td>
   <td>do not prompt, automatically pick the first choice for all prompts</td></tr>
   <tr><td>-q</td>
   <td>--quiet</td>
   <td>suppress output</td></tr>
   <tr><td>-v</td>
   <td>--verbose</td>
   <td>enable additional output</td></tr>
   <tr><td></td>
   <td>--color TYPE</td>
   <td>when to colorize (boolean, always, auto, never, or debug)</td></tr>
   <tr><td></td>
   <td>--config CONFIG [+]</td>
   <td>set/override config option (use 'section.name=value')</td></tr>
   <tr><td></td>
   <td>--debug</td>
   <td>enable debugging output</td></tr>
   <tr><td></td>
   <td>--debugger</td>
   <td>start debugger</td></tr>
   <tr><td></td>
   <td>--encoding ENCODE</td>
   <td>set the charset encoding (default: ascii)</td></tr>
   <tr><td></td>
   <td>--encodingmode MODE</td>
   <td>set the charset encoding mode (default: strict)</td></tr>
   <tr><td></td>
   <td>--traceback</td>
   <td>always print a traceback on exception</td></tr>
   <tr><td></td>
   <td>--time</td>
   <td>time how long the command takes</td></tr>
   <tr><td></td>
   <td>--profile</td>
   <td>print command execution profile</td></tr>
   <tr><td></td>
   <td>--version</td>
   <td>output version information and exit</td></tr>
   <tr><td>-h</td>
   <td>--help</td>
   <td>display help and exit</td></tr>
   <tr><td></td>
   <td>--hidden</td>
   <td>consider hidden changesets</td></tr>
   <tr><td></td>
   <td>--pager TYPE</td>
   <td>when to paginate (boolean, always, auto, or never) (default: auto)</td></tr>
   </table>
   
   </div>
   </div>
   </div>
   
   
   
   </body>
   </html>
   
 
   $ get-with-headers.py $LOCALIP:$HGPORT "help/remove"
   200 Script output follows
   
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
   <head>
   <link rel="icon" href="/static/hgicon.png" type="image/png" />
   <meta name="robots" content="index, nofollow" />
   <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
   <script type="text/javascript" src="/static/mercurial.js"></script>
   
   <title>Help: remove</title>
   </head>
   <body>
   
   <div class="container">
   <div class="menu">
   <div class="logo">
   <a href="https://mercurial-scm.org/">
   <img src="/static/hglogo.png" alt="mercurial" /></a>
   </div>
   <ul>
   <li><a href="/shortlog">log</a></li>
   <li><a href="/graph">graph</a></li>
   <li><a href="/tags">tags</a></li>
   <li><a href="/bookmarks">bookmarks</a></li>
   <li><a href="/branches">branches</a></li>
   </ul>
   <ul>
    <li class="active"><a href="/help">help</a></li>
   </ul>
   </div>
   
   <div class="main">
   <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
   <h3>Help: remove</h3>
   
   <form class="search" action="/log">
   
   <p><input name="rev" id="search1" type="text" size="30" value="" /></p>
   <div id="hint">Find changesets by keywords (author, files, the commit message), revision
   number or hash, or <a href="/help/revsets">revset expression</a>.</div>
   </form>
   <div id="doc">
   <p>
   hg remove [OPTION]... FILE...
   </p>
   <p>
   aliases: rm
   </p>
   <p>
   remove the specified files on the next commit
   </p>
   <p>
   Schedule the indicated files for removal from the current branch.
   </p>
   <p>
   This command schedules the files to be removed at the next commit.
   To undo a remove before that, see 'hg revert'. To undo added
   files, see 'hg forget'.
   </p>
   <p>
   -A/--after can be used to remove only files that have already
   been deleted, -f/--force can be used to force deletion, and -Af
   can be used to remove files from the next revision without
   deleting them from the working directory.
   </p>
   <p>
   The following table details the behavior of remove for different
   file states (columns) and option combinations (rows). The file
   states are Added [A], Clean [C], Modified [M] and Missing [!]
   (as reported by 'hg status'). The actions are Warn, Remove
   (from branch) and Delete (from disk):
   </p>
   <table>
   <tr><td>opt/state</td>
   <td>A</td>
   <td>C</td>
   <td>M</td>
   <td>!</td></tr>
   <tr><td>none</td>
   <td>W</td>
   <td>RD</td>
   <td>W</td>
   <td>R</td></tr>
   <tr><td>-f</td>
   <td>R</td>
   <td>RD</td>
   <td>RD</td>
   <td>R</td></tr>
   <tr><td>-A</td>
   <td>W</td>
   <td>W</td>
   <td>W</td>
   <td>R</td></tr>
   <tr><td>-Af</td>
   <td>R</td>
   <td>R</td>
   <td>R</td>
   <td>R</td></tr>
   </table>
   <p>
   <b>Note:</b> 
   </p>
   <p>
   'hg remove' never deletes files in Added [A] state from the
   working directory, not even if &quot;--force&quot; is specified.
   </p>
   <p>
   Returns 0 on success, 1 if any warnings encountered.
   </p>
   <p>
   options ([+] can be repeated):
   </p>
   <table>
   <tr><td>-A</td>
   <td>--after</td>
   <td>record delete for missing files</td></tr>
   <tr><td>-f</td>
   <td>--force</td>
   <td>forget added files, delete modified files</td></tr>
   <tr><td>-S</td>
   <td>--subrepos</td>
   <td>recurse into subrepositories</td></tr>
   <tr><td>-I</td>
   <td>--include PATTERN [+]</td>
   <td>include names matching the given patterns</td></tr>
   <tr><td>-X</td>
   <td>--exclude PATTERN [+]</td>
   <td>exclude names matching the given patterns</td></tr>
   <tr><td>-n</td>
   <td>--dry-run</td>
   <td>do not perform actions, just print output</td></tr>
   </table>
   <p>
   global options ([+] can be repeated):
   </p>
   <table>
   <tr><td>-R</td>
   <td>--repository REPO</td>
   <td>repository root directory or name of overlay bundle file</td></tr>
   <tr><td></td>
   <td>--cwd DIR</td>
   <td>change working directory</td></tr>
   <tr><td>-y</td>
   <td>--noninteractive</td>
   <td>do not prompt, automatically pick the first choice for all prompts</td></tr>
   <tr><td>-q</td>
   <td>--quiet</td>
   <td>suppress output</td></tr>
   <tr><td>-v</td>
   <td>--verbose</td>
   <td>enable additional output</td></tr>
   <tr><td></td>
   <td>--color TYPE</td>
   <td>when to colorize (boolean, always, auto, never, or debug)</td></tr>
   <tr><td></td>
   <td>--config CONFIG [+]</td>
   <td>set/override config option (use 'section.name=value')</td></tr>
   <tr><td></td>
   <td>--debug</td>
   <td>enable debugging output</td></tr>
   <tr><td></td>
   <td>--debugger</td>
   <td>start debugger</td></tr>
   <tr><td></td>
   <td>--encoding ENCODE</td>
   <td>set the charset encoding (default: ascii)</td></tr>
   <tr><td></td>
   <td>--encodingmode MODE</td>
   <td>set the charset encoding mode (default: strict)</td></tr>
   <tr><td></td>
   <td>--traceback</td>
   <td>always print a traceback on exception</td></tr>
   <tr><td></td>
   <td>--time</td>
   <td>time how long the command takes</td></tr>
   <tr><td></td>
   <td>--profile</td>
   <td>print command execution profile</td></tr>
   <tr><td></td>
   <td>--version</td>
   <td>output version information and exit</td></tr>
   <tr><td>-h</td>
   <td>--help</td>
   <td>display help and exit</td></tr>
   <tr><td></td>
   <td>--hidden</td>
   <td>consider hidden changesets</td></tr>
   <tr><td></td>
   <td>--pager TYPE</td>
   <td>when to paginate (boolean, always, auto, or never) (default: auto)</td></tr>
   </table>
   
   </div>
   </div>
   </div>
   
   
   
   </body>
   </html>
   
 
   $ get-with-headers.py $LOCALIP:$HGPORT "help/dates"
   200 Script output follows
   
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
   <head>
   <link rel="icon" href="/static/hgicon.png" type="image/png" />
   <meta name="robots" content="index, nofollow" />
   <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
   <script type="text/javascript" src="/static/mercurial.js"></script>
   
   <title>Help: dates</title>
   </head>
   <body>
   
   <div class="container">
   <div class="menu">
   <div class="logo">
   <a href="https://mercurial-scm.org/">
   <img src="/static/hglogo.png" alt="mercurial" /></a>
   </div>
   <ul>
   <li><a href="/shortlog">log</a></li>
   <li><a href="/graph">graph</a></li>
   <li><a href="/tags">tags</a></li>
   <li><a href="/bookmarks">bookmarks</a></li>
   <li><a href="/branches">branches</a></li>
   </ul>
   <ul>
    <li class="active"><a href="/help">help</a></li>
   </ul>
   </div>
   
   <div class="main">
   <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
   <h3>Help: dates</h3>
   
   <form class="search" action="/log">
   
   <p><input name="rev" id="search1" type="text" size="30" value="" /></p>
   <div id="hint">Find changesets by keywords (author, files, the commit message), revision
   number or hash, or <a href="/help/revsets">revset expression</a>.</div>
   </form>
   <div id="doc">
   <h1>Date Formats</h1>
   <p>
   Some commands allow the user to specify a date, e.g.:
   </p>
   <ul>
    <li> backout, commit, import, tag: Specify the commit date.
    <li> log, revert, update: Select revision(s) by date.
   </ul>
   <p>
   Many date formats are valid. Here are some examples:
   </p>
   <ul>
    <li> &quot;Wed Dec 6 13:18:29 2006&quot; (local timezone assumed)
    <li> &quot;Dec 6 13:18 -0600&quot; (year assumed, time offset provided)
    <li> &quot;Dec 6 13:18 UTC&quot; (UTC and GMT are aliases for +0000)
    <li> &quot;Dec 6&quot; (midnight)
    <li> &quot;13:18&quot; (today assumed)
    <li> &quot;3:39&quot; (3:39AM assumed)
    <li> &quot;3:39pm&quot; (15:39)
    <li> &quot;2006-12-06 13:18:29&quot; (ISO 8601 format)
    <li> &quot;2006-12-6 13:18&quot;
    <li> &quot;2006-12-6&quot;
    <li> &quot;12-6&quot;
    <li> &quot;12/6&quot;
    <li> &quot;12/6/6&quot; (Dec 6 2006)
    <li> &quot;today&quot; (midnight)
    <li> &quot;yesterday&quot; (midnight)
    <li> &quot;now&quot; - right now
   </ul>
   <p>
   Lastly, there is Mercurial's internal format:
   </p>
   <ul>
    <li> &quot;1165411109 0&quot; (Wed Dec 6 13:18:29 2006 UTC)
   </ul>
   <p>
   This is the internal representation format for dates. The first number
   is the number of seconds since the epoch (1970-01-01 00:00 UTC). The
   second is the offset of the local timezone, in seconds west of UTC
   (negative if the timezone is east of UTC).
   </p>
   <p>
   The log command also accepts date ranges:
   </p>
   <ul>
    <li> &quot;&lt;DATE&quot; - at or before a given date/time
    <li> &quot;&gt;DATE&quot; - on or after a given date/time
    <li> &quot;DATE to DATE&quot; - a date range, inclusive
    <li> &quot;-DAYS&quot; - within a given number of days from today
   </ul>
   
   </div>
   </div>
   </div>
   
   
   
   </body>
   </html>
   
 
   $ get-with-headers.py $LOCALIP:$HGPORT "help/pager"
   200 Script output follows
   
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
   <head>
   <link rel="icon" href="/static/hgicon.png" type="image/png" />
   <meta name="robots" content="index, nofollow" />
   <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
   <script type="text/javascript" src="/static/mercurial.js"></script>
   
   <title>Help: pager</title>
   </head>
   <body>
   
   <div class="container">
   <div class="menu">
   <div class="logo">
   <a href="https://mercurial-scm.org/">
   <img src="/static/hglogo.png" alt="mercurial" /></a>
   </div>
   <ul>
   <li><a href="/shortlog">log</a></li>
   <li><a href="/graph">graph</a></li>
   <li><a href="/tags">tags</a></li>
   <li><a href="/bookmarks">bookmarks</a></li>
   <li><a href="/branches">branches</a></li>
   </ul>
   <ul>
    <li class="active"><a href="/help">help</a></li>
   </ul>
   </div>
   
   <div class="main">
   <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
   <h3>Help: pager</h3>
   
   <form class="search" action="/log">
   
   <p><input name="rev" id="search1" type="text" size="30" value="" /></p>
   <div id="hint">Find changesets by keywords (author, files, the commit message), revision
   number or hash, or <a href="/help/revsets">revset expression</a>.</div>
   </form>
   <div id="doc">
   <h1>Pager Support</h1>
   <p>
   Some Mercurial commands can produce a lot of output, and Mercurial will
   attempt to use a pager to make those commands more pleasant.
   </p>
   <p>
   To set the pager that should be used, set the application variable:
   </p>
   <pre>
   [pager]
   pager = less -FRX
   </pre>
   <p>
   If no pager is set in the user or repository configuration, Mercurial uses the
   environment variable $PAGER. If $PAGER is not set, pager.pager from the default
   or system configuration is used. If none of these are set, a default pager will
   be used, typically 'less' on Unix and 'more' on Windows.
   </p>
   <p>
   You can disable the pager for certain commands by adding them to the
   pager.ignore list:
   </p>
   <pre>
   [pager]
   ignore = version, help, update
   </pre>
   <p>
   To ignore global commands like 'hg version' or 'hg help', you have
   to specify them in your user configuration file.
   </p>
   <p>
   To control whether the pager is used at all for an individual command,
   you can use --pager=&lt;value&gt;:
   </p>
   <ul>
    <li> use as needed: 'auto'.
    <li> require the pager: 'yes' or 'on'.
    <li> suppress the pager: 'no' or 'off' (any unrecognized value   will also work).
   </ul>
   <p>
   To globally turn off all attempts to use a pager, set:
   </p>
   <pre>
   [ui]
   paginate = never
   </pre>
   <p>
   which will prevent the pager from running.
   </p>
   
   </div>
   </div>
   </div>
   
   
   
   </body>
   </html>
   
 
 Sub-topic indexes rendered properly
 
   $ get-with-headers.py $LOCALIP:$HGPORT "help/internals"
   200 Script output follows
   
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
   <head>
   <link rel="icon" href="/static/hgicon.png" type="image/png" />
   <meta name="robots" content="index, nofollow" />
   <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
   <script type="text/javascript" src="/static/mercurial.js"></script>
   
   <title>Help: internals</title>
   </head>
   <body>
   
   <div class="container">
   <div class="menu">
   <div class="logo">
   <a href="https://mercurial-scm.org/">
   <img src="/static/hglogo.png" alt="mercurial" /></a>
   </div>
   <ul>
   <li><a href="/shortlog">log</a></li>
   <li><a href="/graph">graph</a></li>
   <li><a href="/tags">tags</a></li>
   <li><a href="/bookmarks">bookmarks</a></li>
   <li><a href="/branches">branches</a></li>
   </ul>
   <ul>
   <li><a href="/help">help</a></li>
   </ul>
   </div>
   
   <div class="main">
   <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
   
   <form class="search" action="/log">
   
   <p><input name="rev" id="search1" type="text" size="30" value="" /></p>
   <div id="hint">Find changesets by keywords (author, files, the commit message), revision
   number or hash, or <a href="/help/revsets">revset expression</a>.</div>
   </form>
   <table class="bigtable">
   <tr><td colspan="2"><h2><a name="topics" href="#topics">Topics</a></h2></td></tr>
   
   <tr><td>
   <a href="/help/internals.bid-merge">
   bid-merge
   </a>
   </td><td>
   Bid Merge Algorithm
   </td></tr>
   <tr><td>
   <a href="/help/internals.bundle2">
   bundle2
   </a>
   </td><td>
   Bundle2
   </td></tr>
   <tr><td>
   <a href="/help/internals.bundles">
   bundles
   </a>
   </td><td>
   Bundles
   </td></tr>
   <tr><td>
   <a href="/help/internals.cbor">
   cbor
   </a>
   </td><td>
   CBOR
   </td></tr>
   <tr><td>
   <a href="/help/internals.censor">
   censor
   </a>
   </td><td>
   Censor
   </td></tr>
   <tr><td>
   <a href="/help/internals.changegroups">
   changegroups
   </a>
   </td><td>
   Changegroups
   </td></tr>
   <tr><td>
   <a href="/help/internals.config">
   config
   </a>
   </td><td>
   Config Registrar
   </td></tr>
   <tr><td>
   <a href="/help/internals.extensions">
   extensions
   </a>
   </td><td>
   Extension API
   </td></tr>
   <tr><td>
   <a href="/help/internals.mergestate">
   mergestate
   </a>
   </td><td>
   Mergestate
   </td></tr>
   <tr><td>
   <a href="/help/internals.requirements">
   requirements
   </a>
   </td><td>
   Repository Requirements
   </td></tr>
   <tr><td>
   <a href="/help/internals.revlogs">
   revlogs
   </a>
   </td><td>
   Revision Logs
   </td></tr>
   <tr><td>
   <a href="/help/internals.wireprotocol">
   wireprotocol
   </a>
   </td><td>
   Wire Protocol
   </td></tr>
   <tr><td>
   <a href="/help/internals.wireprotocolrpc">
   wireprotocolrpc
   </a>
   </td><td>
   Wire Protocol RPC
   </td></tr>
   <tr><td>
   <a href="/help/internals.wireprotocolv2">
   wireprotocolv2
   </a>
   </td><td>
   Wire Protocol Version 2
   </td></tr>
   
   
   
   
   
   </table>
   </div>
   </div>
   
   
   
   </body>
   </html>
   
 
 Sub-topic topics rendered properly
 
   $ get-with-headers.py $LOCALIP:$HGPORT "help/internals.changegroups"
   200 Script output follows
   
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
   <head>
   <link rel="icon" href="/static/hgicon.png" type="image/png" />
   <meta name="robots" content="index, nofollow" />
   <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
   <script type="text/javascript" src="/static/mercurial.js"></script>
   
   <title>Help: internals.changegroups</title>
   </head>
   <body>
   
   <div class="container">
   <div class="menu">
   <div class="logo">
   <a href="https://mercurial-scm.org/">
   <img src="/static/hglogo.png" alt="mercurial" /></a>
   </div>
   <ul>
   <li><a href="/shortlog">log</a></li>
   <li><a href="/graph">graph</a></li>
   <li><a href="/tags">tags</a></li>
   <li><a href="/bookmarks">bookmarks</a></li>
   <li><a href="/branches">branches</a></li>
   </ul>
   <ul>
    <li class="active"><a href="/help">help</a></li>
   </ul>
   </div>
   
   <div class="main">
   <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
   <h3>Help: internals.changegroups</h3>
   
   <form class="search" action="/log">
   
   <p><input name="rev" id="search1" type="text" size="30" value="" /></p>
   <div id="hint">Find changesets by keywords (author, files, the commit message), revision
   number or hash, or <a href="/help/revsets">revset expression</a>.</div>
   </form>
   <div id="doc">
   <h1>Changegroups</h1>
   <p>
   Changegroups are representations of repository revlog data, specifically
   the changelog data, root/flat manifest data, treemanifest data, and
   filelogs.
   </p>
   <p>
   There are 3 versions of changegroups: &quot;1&quot;, &quot;2&quot;, and &quot;3&quot;. From a
   high-level, versions &quot;1&quot; and &quot;2&quot; are almost exactly the same, with the
   only difference being an additional item in the *delta header*. Version
   &quot;3&quot; adds support for storage flags in the *delta header* and optionally
   exchanging treemanifests (enabled by setting an option on the
   &quot;changegroup&quot; part in the bundle2).
   </p>
   <p>
   Changegroups when not exchanging treemanifests consist of 3 logical
   segments:
   </p>
   <pre>
   +---------------------------------+
   |           |          |          |
   | changeset | manifest | filelogs |
   |           |          |          |
   |           |          |          |
   +---------------------------------+
   </pre>
   <p>
   When exchanging treemanifests, there are 4 logical segments:
   </p>
   <pre>
   +-------------------------------------------------+
   |           |          |               |          |
   | changeset |   root   | treemanifests | filelogs |
   |           | manifest |               |          |
   |           |          |               |          |
   +-------------------------------------------------+
   </pre>
   <p>
   The principle building block of each segment is a *chunk*. A *chunk*
   is a framed piece of data:
   </p>
   <pre>
   +---------------------------------------+
   |           |                           |
   |  length   |           data            |
   | (4 bytes) |   (&lt;length - 4&gt; bytes)    |
   |           |                           |
   +---------------------------------------+
   </pre>
   <p>
   All integers are big-endian signed integers. Each chunk starts with a 32-bit
   integer indicating the length of the entire chunk (including the length field
   itself).
   </p>
   <p>
   There is a special case chunk that has a value of 0 for the length
   (&quot;0x00000000&quot;). We call this an *empty chunk*.
   </p>
   <h2>Delta Groups</h2>
   <p>
   A *delta group* expresses the content of a revlog as a series of deltas,
   or patches against previous revisions.
   </p>
   <p>
   Delta groups consist of 0 or more *chunks* followed by the *empty chunk*
   to signal the end of the delta group:
   </p>
   <pre>
   +------------------------------------------------------------------------+
   |                |             |               |             |           |
   | chunk0 length  | chunk0 data | chunk1 length | chunk1 data |    0x0    |
   |   (4 bytes)    |  (various)  |   (4 bytes)   |  (various)  | (4 bytes) |
   |                |             |               |             |           |
   +------------------------------------------------------------------------+
   </pre>
   <p>
   Each *chunk*'s data consists of the following:
   </p>
   <pre>
   +---------------------------------------+
   |                        |              |
   |     delta header       |  delta data  |
   |  (various by version)  |  (various)   |
   |                        |              |
   +---------------------------------------+
   </pre>
   <p>
   The *delta data* is a series of *delta*s that describe a diff from an existing
   entry (either that the recipient already has, or previously specified in the
   bundle/changegroup).
   </p>
   <p>
   The *delta header* is different between versions &quot;1&quot;, &quot;2&quot;, and
   &quot;3&quot; of the changegroup format.
   </p>
   <p>
   Version 1 (headerlen=80):
   </p>
   <pre>
   +------------------------------------------------------+
   |            |             |             |             |
   |    node    |   p1 node   |   p2 node   |  link node  |
   | (20 bytes) |  (20 bytes) |  (20 bytes) |  (20 bytes) |
   |            |             |             |             |
   +------------------------------------------------------+
   </pre>
   <p>
   Version 2 (headerlen=100):
   </p>
   <pre>
   +------------------------------------------------------------------+
   |            |             |             |            |            |
   |    node    |   p1 node   |   p2 node   | base node  | link node  |
   | (20 bytes) |  (20 bytes) |  (20 bytes) | (20 bytes) | (20 bytes) |
   |            |             |             |            |            |
   +------------------------------------------------------------------+
   </pre>
   <p>
   Version 3 (headerlen=102):
   </p>
   <pre>
   +------------------------------------------------------------------------------+
   |            |             |             |            |            |           |
   |    node    |   p1 node   |   p2 node   | base node  | link node  |   flags   |
   | (20 bytes) |  (20 bytes) |  (20 bytes) | (20 bytes) | (20 bytes) | (2 bytes) |
   |            |             |             |            |            |           |
   +------------------------------------------------------------------------------+
   </pre>
   <p>
   The *delta data* consists of &quot;chunklen - 4 - headerlen&quot; bytes, which contain a
   series of *delta*s, densely packed (no separators). These deltas describe a diff
   from an existing entry (either that the recipient already has, or previously
   specified in the bundle/changegroup). The format is described more fully in
   &quot;hg help internals.bdiff&quot;, but briefly:
   </p>
   <pre>
   +---------------------------------------------------------------+
   |              |            |            |                      |
   | start offset | end offset | new length |        content       |
   |  (4 bytes)   |  (4 bytes) |  (4 bytes) | (&lt;new length&gt; bytes) |
   |              |            |            |                      |
   +---------------------------------------------------------------+
   </pre>
   <p>
   Please note that the length field in the delta data does *not* include itself.
   </p>
   <p>
   In version 1, the delta is always applied against the previous node from
   the changegroup or the first parent if this is the first entry in the
   changegroup.
   </p>
   <p>
   In version 2 and up, the delta base node is encoded in the entry in the
   changegroup. This allows the delta to be expressed against any parent,
   which can result in smaller deltas and more efficient encoding of data.
   </p>
   <p>
   The *flags* field holds bitwise flags affecting the processing of revision
   data. The following flags are defined:
   </p>
   <dl>
    <dt>32768
    <dd>Censored revision. The revision's fulltext has been replaced by censor metadata. May only occur on file revisions.
    <dt>16384
    <dd>Ellipsis revision. Revision hash does not match data (likely due to rewritten parents).
    <dt>8192
    <dd>Externally stored. The revision fulltext contains &quot;key:value&quot; &quot;\n&quot; delimited metadata defining an object stored elsewhere. Used by the LFS extension.
   </dl>
   <p>
   For historical reasons, the integer values are identical to revlog version 1
   per-revision storage flags and correspond to bits being set in this 2-byte
   field. Bits were allocated starting from the most-significant bit, hence the
   reverse ordering and allocation of these flags.
   </p>
   <h2>Changeset Segment</h2>
   <p>
   The *changeset segment* consists of a single *delta group* holding
   changelog data. The *empty chunk* at the end of the *delta group* denotes
   the boundary to the *manifest segment*.
   </p>
   <h2>Manifest Segment</h2>
   <p>
   The *manifest segment* consists of a single *delta group* holding manifest
   data. If treemanifests are in use, it contains only the manifest for the
   root directory of the repository. Otherwise, it contains the entire
   manifest data. The *empty chunk* at the end of the *delta group* denotes
   the boundary to the next segment (either the *treemanifests segment* or the
   *filelogs segment*, depending on version and the request options).
   </p>
   <h3>Treemanifests Segment</h3>
   <p>
   The *treemanifests segment* only exists in changegroup version &quot;3&quot;, and
   only if the 'treemanifest' param is part of the bundle2 changegroup part
   (it is not possible to use changegroup version 3 outside of bundle2).
   Aside from the filenames in the *treemanifests segment* containing a
   trailing &quot;/&quot; character, it behaves identically to the *filelogs segment*
   (see below). The final sub-segment is followed by an *empty chunk* (logically,
   a sub-segment with filename size 0). This denotes the boundary to the
   *filelogs segment*.
   </p>
   <h2>Filelogs Segment</h2>
   <p>
   The *filelogs segment* consists of multiple sub-segments, each
   corresponding to an individual file whose data is being described:
   </p>
   <pre>
   +--------------------------------------------------+
   |          |          |          |     |           |
   | filelog0 | filelog1 | filelog2 | ... |    0x0    |
   |          |          |          |     | (4 bytes) |
   |          |          |          |     |           |
   +--------------------------------------------------+
   </pre>
   <p>
   The final filelog sub-segment is followed by an *empty chunk* (logically,
   a sub-segment with filename size 0). This denotes the end of the segment
   and of the overall changegroup.
   </p>
   <p>
   Each filelog sub-segment consists of the following:
   </p>
   <pre>
   +------------------------------------------------------+
   |                 |                      |             |
   | filename length |       filename       | delta group |
   |    (4 bytes)    | (&lt;length - 4&gt; bytes) |  (various)  |
   |                 |                      |             |
   +------------------------------------------------------+
   </pre>
   <p>
   That is, a *chunk* consisting of the filename (not terminated or padded)
   followed by N chunks constituting the *delta group* for this file. The
   *empty chunk* at the end of each *delta group* denotes the boundary to the
   next filelog sub-segment.
   </p>
   
   </div>
   </div>
   </div>
   
   
   
   </body>
   </html>
   
 
   $ get-with-headers.py 127.0.0.1:$HGPORT "help/unknowntopic"
   404 Not Found
   
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
   <head>
   <link rel="icon" href="/static/hgicon.png" type="image/png" />
   <meta name="robots" content="index, nofollow" />
   <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
   <script type="text/javascript" src="/static/mercurial.js"></script>
   
   <title>test: error</title>
   </head>
   <body>
   
   <div class="container">
   <div class="menu">
   <div class="logo">
   <a href="https://mercurial-scm.org/">
   <img src="/static/hglogo.png" width=75 height=90 border=0 alt="mercurial" /></a>
   </div>
   <ul>
   <li><a href="/shortlog">log</a></li>
   <li><a href="/graph">graph</a></li>
   <li><a href="/tags">tags</a></li>
   <li><a href="/bookmarks">bookmarks</a></li>
   <li><a href="/branches">branches</a></li>
   </ul>
   <ul>
   <li><a href="/help">help</a></li>
   </ul>
   </div>
   
   <div class="main">
   
   <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
   <h3>error</h3>
   
   
   <form class="search" action="/log">
   
   <p><input name="rev" id="search1" type="text" size="30" value="" /></p>
   <div id="hint">Find changesets by keywords (author, files, the commit message), revision
   number or hash, or <a href="/help/revsets">revset expression</a>.</div>
   </form>
   
   <div class="description">
   <p>
   An error occurred while processing your request:
   </p>
   <p>
   Not Found
   </p>
   </div>
   </div>
   </div>
   
   
   
   </body>
   </html>
   
   [1]
 
   $ killdaemons.py
 
 #endif