filemerge: create detail of internal merge tools from documentation string

this patch introduces 'internaltoolsmarker' which creates detail of
each internal merge tools from documentation string for 'hg help merge-tools'.

Makefile

@@ -1,116 +1,118
 # If you want to change PREFIX, do not just edit it below. The changed
 # value wont get passed on to recursive make calls. You should instead
 # override the variable on the command like:
 #
 # % make PREFIX=/opt/ install
 
 PREFIX=/usr/local
 export PREFIX
 PYTHON=python
 PURE=
 PYFILES:=$(shell find mercurial hgext doc -name '*.py')
 DOCFILES=mercurial/help/*.txt
 
 help:
 	@echo 'Commonly used make targets:'
 	@echo '  all          - build program and documentation'
 	@echo '  install      - install program and man pages to PREFIX ($(PREFIX))'
 	@echo '  install-home - install with setup.py install --home=HOME ($(HOME))'
 	@echo '  local        - build for inplace usage'
 	@echo '  tests        - run all tests in the automatic test suite'
 	@echo '  test-foo     - run only specified tests (e.g. test-merge1.t)'
 	@echo '  dist         - run all tests and create a source tarball in dist/'
 	@echo '  clean        - remove files created by other targets'
 	@echo '                 (except installed files or dist source tarball)'
 	@echo '  update-pot   - update i18n/hg.pot'
 	@echo
 	@echo 'Example for a system-wide installation under /usr/local:'
 	@echo '  make all && su -c "make install" && hg version'
 	@echo
 	@echo 'Example for a local installation (usable in this directory):'
 	@echo '  make local && ./hg version'
 
 all: build doc
 
 local:
 	$(PYTHON) setup.py $(PURE) build_py -c -d . build_ext -i build_mo
 	$(PYTHON) hg version
 
 build:
 	$(PYTHON) setup.py $(PURE) build
 
 doc:
 	$(MAKE) -C doc
 
 clean:
 	-$(PYTHON) setup.py clean --all # ignore errors from this command
 	find . \( -name '*.py[cdo]' -o -name '*.so' \) -exec rm -f '{}' ';'
 	rm -f $(addprefix mercurial/,$(notdir $(wildcard mercurial/pure/*.py)))
 	rm -f MANIFEST MANIFEST.in tests/*.err
 	rm -rf build mercurial/locale
 	$(MAKE) -C doc clean
 
 install: install-bin install-doc
 
 install-bin: build
 	$(PYTHON) setup.py $(PURE) install --root="$(DESTDIR)/" --prefix="$(PREFIX)" --force
 
 install-doc: doc
 	cd doc && $(MAKE) $(MFLAGS) install
 
 install-home: install-home-bin install-home-doc
 
 install-home-bin: build
 	$(PYTHON) setup.py $(PURE) install --home="$(HOME)" --force
 
 install-home-doc: doc
 	cd doc && $(MAKE) $(MFLAGS) PREFIX="$(HOME)" install
 
 MANIFEST-doc:
 	$(MAKE) -C doc MANIFEST
 
 MANIFEST.in: MANIFEST-doc
 	hg manifest | sed -e 's/^/include /' > MANIFEST.in
 	echo include mercurial/__version__.py >> MANIFEST.in
 	sed -e 's/^/include /' < doc/MANIFEST >> MANIFEST.in
 
 dist:	tests dist-notests
 
 dist-notests:	doc MANIFEST.in
 	TAR_OPTIONS="--owner=root --group=root --mode=u+w,go-w,a+rX-s" $(PYTHON) setup.py -q sdist
 
 check: tests
 
 tests:
 	cd tests && $(PYTHON) run-tests.py $(TESTFLAGS)
 
 test-%:
 	cd tests && $(PYTHON) run-tests.py $(TESTFLAGS) $@
 
 update-pot: i18n/hg.pot
 
 i18n/hg.pot: $(PYFILES) $(DOCFILES)
 	$(PYTHON) i18n/hggettext mercurial/commands.py \
-	  hgext/*.py hgext/*/__init__.py mercurial/fileset.py mercurial/revset.py \
+	  hgext/*.py hgext/*/__init__.py \
+	  mercurial/fileset.py mercurial/revset.py \
 	  mercurial/templatefilters.py mercurial/templatekw.py \
+	  mercurial/filemerge.py \
 	  $(DOCFILES) > i18n/hg.pot
         # All strings marked for translation in Mercurial contain
         # ASCII characters only. But some files contain string
         # literals like this '\037\213'. xgettext thinks it has to
         # parse them even though they are not marked for translation.
         # Extracting with an explicit encoding of ISO-8859-1 will make
         # xgettext "parse" and ignore them.
 	echo $(PYFILES) | xargs \
 	  xgettext --package-name "Mercurial" \
 	  --msgid-bugs-address "<[e-mail]>" \
 	  --copyright-holder "Matt Mackall <[e-mail]> and others" \
 	  --from-code ISO-8859-1 --join --sort-by-file --add-comments=i18n: \
 	  -d hg -p i18n -o hg.pot
 	$(PYTHON) i18n/posplit i18n/hg.pot
 
 %.po: i18n/hg.pot
 	msgmerge --no-location --update $@ $^
 
 .PHONY: help all local build doc clean install install-bin install-doc \
 	install-home install-home-bin install-home-doc dist dist-notests tests \
 	update-pot

mercurial/filemerge.py

@@ -1,342 +1,367
 # 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 node import short
 from i18n import _
 import util, simplemerge, match, error
 import os, tempfile, re, filecmp
 
 def _toolstr(ui, tool, part, default=""):
     return ui.config("merge-tools", tool + "." + part, default)
 
 def _toolbool(ui, tool, part, default=False):
     return ui.configbool("merge-tools", tool + "." + part, default)
 
 def _toollist(ui, tool, part, default=[]):
     return ui.configlist("merge-tools", tool + "." + part, default)
 
-_internal = {}
+internals = {}
 
 def internaltool(name, trymerge, onfailure=None):
     '''return a decorator for populating internal merge tool table'''
     def decorator(func):
-        _internal[name] = func
+        internals[name] = func
         func.trymerge = trymerge
         func.onfailure = onfailure
         return func
     return decorator
 
 def _findtool(ui, tool):
-    if tool in _internal:
+    if tool in internals:
         return tool
     for kn in ("regkey", "regkeyalt"):
         k = _toolstr(ui, tool, kn)
         if not k:
             continue
         p = util.lookupreg(k, _toolstr(ui, tool, "regname"))
         if p:
             p = util.findexe(p + _toolstr(ui, tool, "regappend"))
             if p:
                 return p
     exe = _toolstr(ui, tool, "executable", tool)
     return util.findexe(util.expandpath(exe))
 
 def _picktool(repo, ui, path, binary, symlink):
     def check(tool, pat, symlink, binary):
         tmsg = tool
         if pat:
             tmsg += " specified for " + pat
         if not _findtool(ui, tool):
             if pat: # explicitly requested tool deserves a warning
                 ui.warn(_("couldn't find merge tool %s\n") % tmsg)
             else: # configured but non-existing tools are more silent
                 ui.note(_("couldn't find merge tool %s\n") % tmsg)
         elif symlink and not _toolbool(ui, tool, "symlink"):
             ui.warn(_("tool %s can't handle symlinks\n") % tmsg)
         elif binary and not _toolbool(ui, tool, "binary"):
             ui.warn(_("tool %s can't handle binary\n") % tmsg)
         elif not util.gui() and _toolbool(ui, tool, "gui"):
             ui.warn(_("tool %s requires a GUI\n") % tmsg)
         else:
             return True
         return False
 
     # forcemerge comes from command line arguments, highest priority
     force = ui.config('ui', 'forcemerge')
     if force:
         toolpath = _findtool(ui, force)
         if toolpath:
             return (force, '"' + toolpath + '"')
         else:
             # mimic HGMERGE if given tool not found
             return (force, force)
 
     # HGMERGE takes next precedence
     hgmerge = os.environ.get("HGMERGE")
     if hgmerge:
         return (hgmerge, hgmerge)
 
     # then patterns
     for pat, tool in ui.configitems("merge-patterns"):
         mf = match.match(repo.root, '', [pat])
         if mf(path) and check(tool, pat, symlink, False):
             toolpath = _findtool(ui, tool)
             return (tool, '"' + toolpath + '"')
 
     # then merge tools
     tools = {}
     for k, v in ui.configitems("merge-tools"):
         t = k.split('.')[0]
         if t not in tools:
             tools[t] = int(_toolstr(ui, t, "priority", "0"))
     names = tools.keys()
     tools = sorted([(-p, t) for t, p in tools.items()])
     uimerge = ui.config("ui", "merge")
     if uimerge:
         if uimerge not in names:
             return (uimerge, uimerge)
         tools.insert(0, (None, uimerge)) # highest priority
     tools.append((None, "hgmerge")) # the old default, if found
     for p, t in tools:
         if check(t, None, symlink, binary):
             toolpath = _findtool(ui, t)
             return (t, '"' + toolpath + '"')
     # internal merge as last resort
     return (not (symlink or binary) and "internal:merge" or None, None)
 
 def _eoltype(data):
     "Guess the EOL type of a file"
     if '\0' in data: # binary
         return None
     if '\r\n' in data: # Windows
         return '\r\n'
     if '\r' in data: # Old Mac
         return '\r'
     if '\n' in data: # UNIX
         return '\n'
     return None # unknown
 
 def _matcheol(file, origfile):
     "Convert EOL markers in a file to match origfile"
     tostyle = _eoltype(util.readfile(origfile))
     if tostyle:
         data = util.readfile(file)
         style = _eoltype(data)
         if style:
             newdata = data.replace(style, tostyle)
             if newdata != data:
                 util.writefile(file, newdata)
 
 @internaltool('internal:prompt', False)
 def _iprompt(repo, mynode, orig, fcd, fco, fca, toolconf):
+    """``internal:prompt``
+    Asks the user which of the local or the other version to keep as
+    the merged version."""
     ui = repo.ui
     fd = fcd.path()
 
     if ui.promptchoice(_(" no tool found to merge %s\n"
                          "keep (l)ocal or take (o)ther?") % fd,
                        (_("&Local"), _("&Other")), 0):
         return _iother(repo, mynode, orig, fcd, fco, fca, toolconf)
     else:
         return _ilocal(repo, mynode, orig, fcd, fco, fca, toolconf)
 
 @internaltool('internal:local', False)
 def _ilocal(repo, mynode, orig, fcd, fco, fca, toolconf):
+    """``internal:local``
+    Uses the local version of files as the merged version."""
     return 0
 
 @internaltool('internal:other', False)
 def _iother(repo, mynode, orig, fcd, fco, fca, toolconf):
+    """``internal:other``
+    Uses the other version of files as the merged version."""
     repo.wwrite(fcd.path(), fco.data(), fco.flags())
     return 0
 
 @internaltool('internal:fail', False)
 def _ifail(repo, mynode, orig, fcd, fco, fca, toolconf):
+    """``internal: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."""
     return 1
 
 def _premerge(repo, toolconf, files):
     tool, toolpath, binary, symlink = toolconf
     a, b, c, back = files
 
     ui = repo.ui
 
     # do we attempt to simplemerge first?
     try:
         premerge = _toolbool(ui, tool, "premerge", not (binary or symlink))
     except error.ConfigError:
         premerge = _toolstr(ui, tool, "premerge").lower()
         valid = 'keep'.split()
         if premerge not in valid:
             _valid = ', '.join(["'" + v + "'" for v in valid])
             raise error.ConfigError(_("%s.premerge not valid "
                                       "('%s' is neither boolean nor %s)") %
                                     (tool, premerge, _valid))
 
     if premerge:
         r = simplemerge.simplemerge(ui, a, b, c, quiet=True)
         if not r:
             ui.debug(" premerge successful\n")
             return 0
         if premerge != 'keep':
             util.copyfile(back, a) # restore from backup and try again
     return 1 # continue merging
 
 @internaltool('internal:merge', True,
               _("merging %s incomplete! "
                 "(edit conflicts, then use 'hg resolve --mark')\n"))
 def _imerge(repo, mynode, orig, fcd, fco, fca, toolconf, files):
+    """``internal: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."""
     r = _premerge(repo, toolconf, files)
     if r:
         a, b, c, back = files
 
         ui = repo.ui
 
         r = simplemerge.simplemerge(ui, a, b, c, label=['local', 'other'])
         return True, r
     return False, 0
 
 @internaltool('internal:dump', True)
 def _idump(repo, mynode, orig, fcd, fco, fca, toolconf, files):
+    """``internal: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``."""
     r = _premerge(repo, toolconf, files)
     if r:
         a, b, c, back = files
 
         fd = fcd.path()
 
         util.copyfile(a, a + ".local")
         repo.wwrite(fd + ".other", fco.data(), fco.flags())
         repo.wwrite(fd + ".base", fca.data(), fca.flags())
     return False, r
 
 def _xmerge(repo, mynode, orig, fcd, fco, fca, toolconf, files):
     r = _premerge(repo, toolconf, files)
     if r:
         tool, toolpath, binary, symlink = toolconf
         a, b, c, back = files
         out = ""
         env = dict(HG_FILE=fcd.path(),
                    HG_MY_NODE=short(mynode),
                    HG_OTHER_NODE=str(fco.changectx()),
                    HG_BASE_NODE=str(fca.changectx()),
                    HG_MY_ISLINK='l' in fcd.flags(),
                    HG_OTHER_ISLINK='l' in fco.flags(),
                    HG_BASE_ISLINK='l' in fca.flags())
 
         ui = repo.ui
 
         args = _toolstr(ui, tool, "args", '$local $base $other')
         if "$output" in args:
             out, a = a, back # read input from backup, write to original
         replace = dict(local=a, base=b, other=c, output=out)
         args = util.interpolate(r'\$', replace, args,
                                 lambda s: '"%s"' % util.localpath(s))
         r = util.system(toolpath + ' ' + args, cwd=repo.root, environ=env,
                         out=ui.fout)
         return True, r
     return False, 0
 
 def filemerge(repo, mynode, orig, fcd, fco, fca):
     """perform a 3-way merge in the working directory
 
     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
     """
 
     def temp(prefix, ctx):
         pre = "%s~%s." % (os.path.basename(ctx.path()), prefix)
         (fd, name) = tempfile.mkstemp(prefix=pre)
         data = repo.wwritedata(ctx.path(), ctx.data())
         f = os.fdopen(fd, "wb")
         f.write(data)
         f.close()
         return name
 
     if not fco.cmp(fcd): # files identical?
         return None
 
     ui = repo.ui
     fd = fcd.path()
     binary = fcd.isbinary() or fco.isbinary() or fca.isbinary()
     symlink = 'l' in fcd.flags() + fco.flags()
     tool, toolpath = _picktool(repo, ui, fd, binary, symlink)
     ui.debug("picked tool '%s' for %s (binary %s symlink %s)\n" %
                (tool, fd, binary, symlink))
 
-    if tool in _internal:
-        func = _internal[tool]
+    if tool in internals:
+        func = internals[tool]
         trymerge = func.trymerge
         onfailure = func.onfailure
     else:
         func = _xmerge
         trymerge = True
         onfailure = _("merging %s failed!\n")
 
     toolconf = tool, toolpath, binary, symlink
 
     if not trymerge:
         return func(repo, mynode, orig, fcd, fco, fca, toolconf)
 
     a = repo.wjoin(fd)
     b = temp("base", fca)
     c = temp("other", fco)
     back = a + ".orig"
     util.copyfile(a, back)
 
     if orig != fco.path():
         ui.status(_("merging %s and %s to %s\n") % (orig, fco.path(), fd))
     else:
         ui.status(_("merging %s\n") % fd)
 
     ui.debug("my %s other %s ancestor %s\n" % (fcd, fco, fca))
 
     needcheck, r = func(repo, mynode, orig, fcd, fco, fca, toolconf,
                         (a, b, c, back))
     if not needcheck:
         if r:
             if onfailure:
                 ui.warn(onfailure % fd)
         else:
             os.unlink(back)
 
         os.unlink(b)
         os.unlink(c)
         return r
 
     if not r and (_toolbool(ui, tool, "checkconflicts") or
                   'conflicts' in _toollist(ui, tool, "check")):
         if re.search("^(<<<<<<< .*|=======|>>>>>>> .*)$", fcd.data(),
                      re.MULTILINE):
             r = 1
 
     checked = False
     if 'prompt' in _toollist(ui, tool, "check"):
         checked = True
         if ui.promptchoice(_("was merge of '%s' successful (yn)?") % fd,
                            (_("&Yes"), _("&No")), 1):
             r = 1
 
     if not r and not checked and (_toolbool(ui, tool, "checkchanged") or
                                   'changed' in _toollist(ui, tool, "check")):
         if filecmp.cmp(a, back):
             if ui.promptchoice(_(" output file %s appears unchanged\n"
                                  "was merge successful (yn)?") % fd,
                                (_("&Yes"), _("&No")), 1):
                 r = 1
 
     if _toolbool(ui, tool, "fixeol"):
         _matcheol(a, back)
 
     if r:
         if onfailure:
             ui.warn(onfailure % fd)
     else:
         os.unlink(back)
 
     os.unlink(b)
     os.unlink(c)
     return r
+
+# tell hggettext to extract docstrings from these functions:
+i18nfunctions = internals.values()

mercurial/help.py

@@ -1,110 +1,111
 # help.py - help data for mercurial
 #
 # Copyright 2006 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 i18n import gettext, _
 import sys, os
-import extensions, revset, fileset, templatekw, templatefilters
+import extensions, revset, fileset, templatekw, templatefilters, filemerge
 import util
 
 def listexts(header, exts, indent=1):
     '''return a text listing of the given extensions'''
     if not exts:
         return ''
     maxlength = max(len(e) for e in exts)
     result = '\n%s\n\n' % header
     for name, desc in sorted(exts.iteritems()):
         result += '%s%-*s %s\n' % (' ' * indent, maxlength + 2,
                                    ':%s:' % name, desc)
     return result
 
 def extshelp():
     doc = loaddoc('extensions')()
     doc += listexts(_('enabled extensions:'), extensions.enabled())
     doc += listexts(_('disabled extensions:'), extensions.disabled())
     return doc
 
 def loaddoc(topic):
     """Return a delayed loader for help/topic.txt."""
 
     def loader():
         if util.mainfrozen():
             module = sys.executable
         else:
             module = __file__
         base = os.path.dirname(module)
 
         for dir in ('.', '..'):
             docdir = os.path.join(base, dir, 'help')
             if os.path.isdir(docdir):
                 break
 
         path = os.path.join(docdir, topic + ".txt")
         doc = gettext(util.readfile(path))
         for rewriter in helphooks.get(topic, []):
             doc = rewriter(topic, doc)
         return doc
 
     return loader
 
 helptable = sorted([
     (["config", "hgrc"], _("Configuration Files"), loaddoc('config')),
     (["dates"], _("Date Formats"), loaddoc('dates')),
     (["patterns"], _("File Name Patterns"), loaddoc('patterns')),
     (['environment', 'env'], _('Environment Variables'),
      loaddoc('environment')),
     (['revs', 'revisions'], _('Specifying Single Revisions'),
      loaddoc('revisions')),
     (['mrevs', 'multirevs'], _('Specifying Multiple Revisions'),
      loaddoc('multirevs')),
     (['revset', 'revsets'], _("Specifying Revision Sets"), loaddoc('revsets')),
     (['fileset', 'filesets'], _("Specifying File Sets"), loaddoc('filesets')),
     (['diffs'], _('Diff Formats'), loaddoc('diffs')),
     (['merge-tools'], _('Merge Tools'), loaddoc('merge-tools')),
     (['templating', 'templates'], _('Template Usage'),
      loaddoc('templates')),
     (['urls'], _('URL Paths'), loaddoc('urls')),
     (["extensions"], _("Using additional features"), extshelp),
    (["subrepo", "subrepos"], _("Subrepositories"), loaddoc('subrepos')),
    (["hgweb"], _("Configuring hgweb"), loaddoc('hgweb')),
    (["glossary"], _("Glossary"), loaddoc('glossary')),
    (["hgignore", "ignore"], _("syntax for Mercurial ignore files"),
     loaddoc('hgignore')),
    (["phases"], _("Working with Phases"), loaddoc('phases')),
 ])
 
 # Map topics to lists of callable taking the current topic help and
 # returning the updated version
 helphooks = {}
 
 def addtopichook(topic, rewriter):
     helphooks.setdefault(topic, []).append(rewriter)
 
 def makeitemsdoc(topic, doc, marker, items):
     """Extract docstring from the items key to function mapping, build a
     .single documentation block and use it to overwrite the marker in doc
     """
     entries = []
     for name in sorted(items):
         text = (items[name].__doc__ or '').rstrip()
         if not text:
             continue
         text = gettext(text)
         lines = text.splitlines()
         lines[1:] = [('  ' + l.strip()) for l in lines[1:]]
         entries.append('\n'.join(lines))
     entries = '\n\n'.join(entries)
     return doc.replace(marker, entries)
 
 def addtopicsymbols(topic, marker, symbols):
     def add(topic, doc):
         return makeitemsdoc(topic, doc, marker, symbols)
     addtopichook(topic, add)
 
 addtopicsymbols('filesets', '.. predicatesmarker', fileset.symbols)
+addtopicsymbols('merge-tools', '.. internaltoolsmarker', filemerge.internals)
 addtopicsymbols('revsets', '.. predicatesmarker', revset.symbols)
 addtopicsymbols('templates', '.. keywordsmarker', templatekw.keywords)
 addtopicsymbols('templates', '.. filtersmarker', templatefilters.filters)

mercurial/help/merge-tools.txt

@@ -1,110 +1,84
 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:
 
-``internal: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.
-
-``internal: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.
-
-``internal:local``
-   Uses the local version of files as the merged version.
-
-``internal:other``
-   Uses the other version of files as the merged version.
-
-``internal:prompt``
-   Asks the user which of the local or the other version to keep as
-   the merged version.
-
-``internal: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``.
+.. internaltoolsmarker
 
 Internal tools are always available and do not require a GUI but will by default
 not handle symlinks or binary files.
 
 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. Here, binary capabilities of the
    merge tool are not considered.
 
 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. The merge of the file fails and must be resolved before commit.
 
 .. 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 Mercurial will 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.