copies: properly match result during changeset centric copy tracing

By filtering "during" the iteration we were excluding rename information that
were not in the matched set but that file served as base information for the
matched set.

We now do all copy tracing matching at the end of the process to ensure we raise
proper result.

If we were aggregating information top down instead of bottom up we could do
filtering during processing. However, we don't.

Differential Revision: https://phab.mercurial-scm.org/D9585

mercurial/copies.py

@@ -1,1221 +1,1217 b''
 # coding: utf8
 # copies.py - copy detection for Mercurial
 #
 # Copyright 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 collections
 import os
 
 from .i18n import _
 from .node import (
     nullid,
     nullrev,
 )
 
 from . import (
     match as matchmod,
     pathutil,
     policy,
     pycompat,
     util,
 )
 
 
 from .utils import stringutil
 
 from .revlogutils import (
     flagutil,
     sidedata as sidedatamod,
 )
 
 rustmod = policy.importrust("copy_tracing")
 
 
 def _filter(src, dst, t):
     """filters out invalid copies after chaining"""
 
     # When _chain()'ing copies in 'a' (from 'src' via some other commit 'mid')
     # with copies in 'b' (from 'mid' to 'dst'), we can get the different cases
     # in the following table (not including trivial cases). For example, case 2
     # is where a file existed in 'src' and remained under that name in 'mid' and
     # then was renamed between 'mid' and 'dst'.
     #
     # case src mid dst result
     #   1   x   y   -    -
     #   2   x   y   y   x->y
     #   3   x   y   x    -
     #   4   x   y   z   x->z
     #   5   -   x   y    -
     #   6   x   x   y   x->y
     #
     # _chain() takes care of chaining the copies in 'a' and 'b', but it
     # cannot tell the difference between cases 1 and 2, between 3 and 4, or
     # between 5 and 6, so it includes all cases in its result.
     # Cases 1, 3, and 5 are then removed by _filter().
 
     for k, v in list(t.items()):
         # remove copies from files that didn't exist
         if v not in src:
             del t[k]
         # remove criss-crossed copies
         elif k in src and v in dst:
             del t[k]
         # remove copies to files that were then removed
         elif k not in dst:
             del t[k]
 
 
 def _chain(prefix, suffix):
     """chain two sets of copies 'prefix' and 'suffix'"""
     result = prefix.copy()
     for key, value in pycompat.iteritems(suffix):
         result[key] = prefix.get(value, value)
     return result
 
 
 def _tracefile(fctx, am, basemf):
     """return file context that is the ancestor of fctx present in ancestor
     manifest am
 
     Note: we used to try and stop after a given limit, however checking if that
     limit is reached turned out to be very expensive. we are better off
     disabling that feature."""
 
     for f in fctx.ancestors():
         path = f.path()
         if am.get(path, None) == f.filenode():
             return path
         if basemf and basemf.get(path, None) == f.filenode():
             return path
 
 
 def _dirstatecopies(repo, match=None):
     ds = repo.dirstate
     c = ds.copies().copy()
     for k in list(c):
         if ds[k] not in b'anm' or (match and not match(k)):
             del c[k]
     return c
 
 
 def _computeforwardmissing(a, b, match=None):
     """Computes which files are in b but not a.
     This is its own function so extensions can easily wrap this call to see what
     files _forwardcopies is about to process.
     """
     ma = a.manifest()
     mb = b.manifest()
     return mb.filesnotin(ma, match=match)
 
 
 def usechangesetcentricalgo(repo):
     """Checks if we should use changeset-centric copy algorithms"""
     if repo.filecopiesmode == b'changeset-sidedata':
         return True
     readfrom = repo.ui.config(b'experimental', b'copies.read-from')
     changesetsource = (b'changeset-only', b'compatibility')
     return readfrom in changesetsource
 
 
 def _committedforwardcopies(a, b, base, match):
     """Like _forwardcopies(), but b.rev() cannot be None (working copy)"""
     # files might have to be traced back to the fctx parent of the last
     # one-side-only changeset, but not further back than that
     repo = a._repo
 
     if usechangesetcentricalgo(repo):
         return _changesetforwardcopies(a, b, match)
 
     debug = repo.ui.debugflag and repo.ui.configbool(b'devel', b'debug.copies')
     dbg = repo.ui.debug
     if debug:
         dbg(b'debug.copies:    looking into rename from %s to %s\n' % (a, b))
     am = a.manifest()
     basemf = None if base is None else base.manifest()
 
     # find where new files came from
     # we currently don't try to find where old files went, too expensive
     # this means we can miss a case like 'hg rm b; hg cp a b'
     cm = {}
 
     # Computing the forward missing is quite expensive on large manifests, since
     # it compares the entire manifests. We can optimize it in the common use
     # case of computing what copies are in a commit versus its parent (like
     # during a rebase or histedit). Note, we exclude merge commits from this
     # optimization, since the ctx.files() for a merge commit is not correct for
     # this comparison.
     forwardmissingmatch = match
     if b.p1() == a and b.p2().node() == nullid:
         filesmatcher = matchmod.exact(b.files())
         forwardmissingmatch = matchmod.intersectmatchers(match, filesmatcher)
     missing = _computeforwardmissing(a, b, match=forwardmissingmatch)
 
     ancestrycontext = a._repo.changelog.ancestors([b.rev()], inclusive=True)
 
     if debug:
         dbg(b'debug.copies:      missing files to search: %d\n' % len(missing))
 
     for f in sorted(missing):
         if debug:
             dbg(b'debug.copies:        tracing file: %s\n' % f)
         fctx = b[f]
         fctx._ancestrycontext = ancestrycontext
 
         if debug:
             start = util.timer()
         opath = _tracefile(fctx, am, basemf)
         if opath:
             if debug:
                 dbg(b'debug.copies:          rename of: %s\n' % opath)
             cm[f] = opath
         if debug:
             dbg(
                 b'debug.copies:          time: %f seconds\n'
                 % (util.timer() - start)
             )
     return cm
 
 
 def _revinfo_getter(repo, match):
     """returns a function that returns the following data given a <rev>"
 
     * p1: revision number of first parent
     * p2: revision number of first parent
     * changes: a ChangingFiles object
     """
     cl = repo.changelog
     parents = cl.parentrevs
     flags = cl.flags
 
     HASCOPIESINFO = flagutil.REVIDX_HASCOPIESINFO
 
     changelogrevision = cl.changelogrevision
 
-    alwaysmatch = match.always()
-
-    if rustmod is not None and alwaysmatch:
+    if rustmod is not None:
 
         def revinfo(rev):
             p1, p2 = parents(rev)
             if flags(rev) & HASCOPIESINFO:
                 raw = changelogrevision(rev)._sidedata.get(sidedatamod.SD_FILES)
             else:
                 raw = None
             return (p1, p2, raw)
 
     else:
 
         def revinfo(rev):
             p1, p2 = parents(rev)
             if flags(rev) & HASCOPIESINFO:
                 changes = changelogrevision(rev).changes
             else:
                 changes = None
             return (p1, p2, changes)
 
     return revinfo
 
 
 def cached_is_ancestor(is_ancestor):
     """return a cached version of is_ancestor"""
     cache = {}
 
     def _is_ancestor(anc, desc):
         if anc > desc:
             return False
         elif anc == desc:
             return True
         key = (anc, desc)
         ret = cache.get(key)
         if ret is None:
             ret = cache[key] = is_ancestor(anc, desc)
         return ret
 
     return _is_ancestor
 
 
 def _changesetforwardcopies(a, b, match):
     if a.rev() in (nullrev, b.rev()):
         return {}
 
     repo = a.repo().unfiltered()
     children = {}
 
     cl = repo.changelog
     isancestor = cl.isancestorrev
 
     # To track rename from "A" to B, we need to gather all parent → children
     # edges that are contains in `::B` but not in `::A`.
     #
     #
     # To do so, we need to gather all revisions exclusive¹ to "B" (ie¹: `::b -
     # ::a`) and also all the "roots point", ie the parents of the exclusive set
     # that belong to ::a. These are exactly all the revisions needed to express
     # the parent → children we need to combine.
     #
     # [1] actually, we need to gather all the edges within `(::a)::b`, ie:
     # excluding paths that leads to roots that are not ancestors of `a`. We
     # keep this out of the explanation because it is hard enough without this special case..
 
     parents = cl._uncheckedparentrevs
     graph_roots = (nullrev, nullrev)
 
     ancestors = cl.ancestors([a.rev()], inclusive=True)
     revs = cl.findmissingrevs(common=[a.rev()], heads=[b.rev()])
     roots = set()
     has_graph_roots = False
 
     # iterate over `only(B, A)`
     for r in revs:
         ps = parents(r)
         if ps == graph_roots:
             has_graph_roots = True
         else:
             p1, p2 = ps
 
             # find all the "root points" (see larger comment above)
             if p1 != nullrev and p1 in ancestors:
                 roots.add(p1)
             if p2 != nullrev and p2 in ancestors:
                 roots.add(p2)
     if not roots:
         # no common revision to track copies from
         return {}
     if has_graph_roots:
         # this deal with the special case mentionned in the [1] footnotes. We
         # must filter out revisions that leads to non-common graphroots.
         roots = list(roots)
         m = min(roots)
         h = [b.rev()]
         roots_to_head = cl.reachableroots(m, h, roots, includepath=True)
         roots_to_head = set(roots_to_head)
         revs = [r for r in revs if r in roots_to_head]
 
     if repo.filecopiesmode == b'changeset-sidedata':
         # When using side-data, we will process the edges "from" the children.
         # We iterate over the childre, gathering previous collected data for
         # the parents. Do know when the parents data is no longer necessary, we
         # keep a counter of how many children each revision has.
         #
         # An interresting property of `children_count` is that it only contains
         # revision that will be relevant for a edge of the graph. So if a
         # children has parent not in `children_count`, that edges should not be
         # processed.
         children_count = dict((r, 0) for r in roots)
         for r in revs:
             for p in cl.parentrevs(r):
                 if p == nullrev:
                     continue
                 children_count[r] = 0
                 if p in children_count:
                     children_count[p] += 1
         revinfo = _revinfo_getter(repo, match)
         return _combine_changeset_copies(
             revs, children_count, b.rev(), revinfo, match, isancestor
         )
     else:
         # When not using side-data, we will process the edges "from" the parent.
         # so we need a full mapping of the parent -> children relation.
         children = dict((r, []) for r in roots)
         for r in revs:
             for p in cl.parentrevs(r):
                 if p == nullrev:
                     continue
                 children[r] = []
                 if p in children:
                     children[p].append(r)
         x = revs.pop()
         assert x == b.rev()
         revs.extend(roots)
         revs.sort()
 
         revinfo = _revinfo_getter_extra(repo)
         return _combine_changeset_copies_extra(
             revs, children, b.rev(), revinfo, match, isancestor
         )
 
 
 def _combine_changeset_copies(
     revs, children_count, targetrev, revinfo, match, isancestor
 ):
     """combine the copies information for each item of iterrevs
 
     revs: sorted iterable of revision to visit
     children_count: a {parent: <number-of-relevant-children>} mapping.
     targetrev: the final copies destination revision (not in iterrevs)
     revinfo(rev): a function that return (p1, p2, p1copies, p2copies, removed)
     match: a matcher
 
     It returns the aggregated copies information for `targetrev`.
     """
 
     alwaysmatch = match.always()
 
-    if rustmod is not None and alwaysmatch:
+    if rustmod is not None:
         final_copies = rustmod.combine_changeset_copies(
             list(revs), children_count, targetrev, revinfo, isancestor
         )
     else:
         isancestor = cached_is_ancestor(isancestor)
 
         all_copies = {}
         # iterate over all the "children" side of copy tracing "edge"
         for current_rev in revs:
             p1, p2, changes = revinfo(current_rev)
             current_copies = None
             # iterate over all parents to chain the existing data with the
             # data from the parent → child edge.
             for parent, parent_rev in ((1, p1), (2, p2)):
                 if parent_rev == nullrev:
                     continue
                 remaining_children = children_count.get(parent_rev)
                 if remaining_children is None:
                     continue
                 remaining_children -= 1
                 children_count[parent_rev] = remaining_children
                 if remaining_children:
                     copies = all_copies.get(parent_rev, None)
                 else:
                     copies = all_copies.pop(parent_rev, None)
 
                 if copies is None:
                     # this is a root
                     copies = {}
 
                 newcopies = copies
                 # chain the data in the edge with the existing data
                 if changes is not None:
                     childcopies = {}
                     if parent == 1:
                         childcopies = changes.copied_from_p1
                     elif parent == 2:
                         childcopies = changes.copied_from_p2
 
-                    if not alwaysmatch:
-                        childcopies = {
-                            dst: src
-                            for dst, src in childcopies.items()
-                            if match(dst)
-                        }
                     if childcopies:
                         newcopies = copies.copy()
                         for dest, source in pycompat.iteritems(childcopies):
                             prev = copies.get(source)
                             if prev is not None and prev[1] is not None:
                                 source = prev[1]
                             newcopies[dest] = (current_rev, source)
                         assert newcopies is not copies
                     if changes.removed:
                         if newcopies is copies:
                             newcopies = copies.copy()
                         for f in changes.removed:
                             if f in newcopies:
                                 if newcopies is copies:
                                     # copy on write to avoid affecting potential other
                                     # branches.  when there are no other branches, this
                                     # could be avoided.
                                     newcopies = copies.copy()
                                 newcopies[f] = (current_rev, None)
                 # check potential need to combine the data from another parent (for
                 # that child). See comment below for details.
                 if current_copies is None:
                     current_copies = newcopies
                 elif current_copies is newcopies:
                     # nothing to merge:
                     pass
                 else:
                     # we are the second parent to work on c, we need to merge our
                     # work with the other.
                     #
                     # In case of conflict, parent 1 take precedence over parent 2.
                     # This is an arbitrary choice made anew when implementing
                     # changeset based copies. It was made without regards with
                     # potential filelog related behavior.
                     assert parent == 2
                     current_copies = _merge_copies_dict(
                         newcopies, current_copies, isancestor, changes
                     )
             all_copies[current_rev] = current_copies
 
         # filter out internal details and return a {dest: source mapping}
         final_copies = {}
         for dest, (tt, source) in all_copies[targetrev].items():
             if source is not None:
                 final_copies[dest] = source
+    if not alwaysmatch:
+        for filename in list(final_copies.keys()):
+            if not match(filename):
+                del final_copies[filename]
     return final_copies
 
 
 def _merge_copies_dict(minor, major, isancestor, changes):
     """merge two copies-mapping together, minor and major
 
     In case of conflict, value from "major" will be picked.
 
     - `isancestors(low_rev, high_rev)`: callable return True if `low_rev` is an
                                         ancestors of `high_rev`,
 
     - `ismerged(path)`: callable return True if `path` have been merged in the
                         current revision,
 
     return the resulting dict (in practice, the "minor" object, updated)
     """
     for dest, value in major.items():
         other = minor.get(dest)
         if other is None:
             minor[dest] = value
         else:
             new_tt = value[0]
             other_tt = other[0]
             if value[1] == other[1]:
                 continue
             # content from "major" wins, unless it is older
             # than the branch point or there is a merge
             if new_tt == other_tt:
                 minor[dest] = value
             elif (
                 changes is not None
                 and value[1] is None
                 and dest in changes.salvaged
             ):
                 pass
             elif (
                 changes is not None
                 and other[1] is None
                 and dest in changes.salvaged
             ):
                 minor[dest] = value
             elif changes is not None and dest in changes.merged:
                 minor[dest] = value
             elif not isancestor(new_tt, other_tt):
                 if value[1] is not None:
                     minor[dest] = value
                 elif isancestor(other_tt, new_tt):
                     minor[dest] = value
     return minor
 
 
 def _revinfo_getter_extra(repo):
     """return a function that return multiple data given a <rev>"i
 
     * p1: revision number of first parent
     * p2: revision number of first parent
     * p1copies: mapping of copies from p1
     * p2copies: mapping of copies from p2
     * removed: a list of removed files
     * ismerged: a callback to know if file was merged in that revision
     """
     cl = repo.changelog
     parents = cl.parentrevs
 
     def get_ismerged(rev):
         ctx = repo[rev]
 
         def ismerged(path):
             if path not in ctx.files():
                 return False
             fctx = ctx[path]
             parents = fctx._filelog.parents(fctx._filenode)
             nb_parents = 0
             for n in parents:
                 if n != nullid:
                     nb_parents += 1
             return nb_parents >= 2
 
         return ismerged
 
     def revinfo(rev):
         p1, p2 = parents(rev)
         ctx = repo[rev]
         p1copies, p2copies = ctx._copies
         removed = ctx.filesremoved()
         return p1, p2, p1copies, p2copies, removed, get_ismerged(rev)
 
     return revinfo
 
 
 def _combine_changeset_copies_extra(
     revs, children, targetrev, revinfo, match, isancestor
 ):
     """version of `_combine_changeset_copies` that works with the Google
     specific "extra" based storage for copy information"""
     all_copies = {}
     alwaysmatch = match.always()
     for r in revs:
         copies = all_copies.pop(r, None)
         if copies is None:
             # this is a root
             copies = {}
         for i, c in enumerate(children[r]):
             p1, p2, p1copies, p2copies, removed, ismerged = revinfo(c)
             if r == p1:
                 parent = 1
                 childcopies = p1copies
             else:
                 assert r == p2
                 parent = 2
                 childcopies = p2copies
             if not alwaysmatch:
                 childcopies = {
                     dst: src for dst, src in childcopies.items() if match(dst)
                 }
             newcopies = copies
             if childcopies:
                 newcopies = copies.copy()
                 for dest, source in pycompat.iteritems(childcopies):
                     prev = copies.get(source)
                     if prev is not None and prev[1] is not None:
                         source = prev[1]
                     newcopies[dest] = (c, source)
                 assert newcopies is not copies
             for f in removed:
                 if f in newcopies:
                     if newcopies is copies:
                         # copy on write to avoid affecting potential other
                         # branches.  when there are no other branches, this
                         # could be avoided.
                         newcopies = copies.copy()
                     newcopies[f] = (c, None)
             othercopies = all_copies.get(c)
             if othercopies is None:
                 all_copies[c] = newcopies
             else:
                 # we are the second parent to work on c, we need to merge our
                 # work with the other.
                 #
                 # In case of conflict, parent 1 take precedence over parent 2.
                 # This is an arbitrary choice made anew when implementing
                 # changeset based copies. It was made without regards with
                 # potential filelog related behavior.
                 if parent == 1:
                     _merge_copies_dict_extra(
                         othercopies, newcopies, isancestor, ismerged
                     )
                 else:
                     _merge_copies_dict_extra(
                         newcopies, othercopies, isancestor, ismerged
                     )
                     all_copies[c] = newcopies
 
     final_copies = {}
     for dest, (tt, source) in all_copies[targetrev].items():
         if source is not None:
             final_copies[dest] = source
     return final_copies
 
 
 def _merge_copies_dict_extra(minor, major, isancestor, ismerged):
     """version of `_merge_copies_dict` that works with the Google
     specific "extra" based storage for copy information"""
     for dest, value in major.items():
         other = minor.get(dest)
         if other is None:
             minor[dest] = value
         else:
             new_tt = value[0]
             other_tt = other[0]
             if value[1] == other[1]:
                 continue
             # content from "major" wins, unless it is older
             # than the branch point or there is a merge
             if (
                 new_tt == other_tt
                 or not isancestor(new_tt, other_tt)
                 or ismerged(dest)
             ):
                 minor[dest] = value
 
 
 def _forwardcopies(a, b, base=None, match=None):
     """find {dst@b: src@a} copy mapping where a is an ancestor of b"""
 
     if base is None:
         base = a
     match = a.repo().narrowmatch(match)
     # check for working copy
     if b.rev() is None:
         cm = _committedforwardcopies(a, b.p1(), base, match)
         # combine copies from dirstate if necessary
         copies = _chain(cm, _dirstatecopies(b._repo, match))
     else:
         copies = _committedforwardcopies(a, b, base, match)
     return copies
 
 
 def _backwardrenames(a, b, match):
     if a._repo.ui.config(b'experimental', b'copytrace') == b'off':
         return {}
 
     # Even though we're not taking copies into account, 1:n rename situations
     # can still exist (e.g. hg cp a b; hg mv a c). In those cases we
     # arbitrarily pick one of the renames.
     # We don't want to pass in "match" here, since that would filter
     # the destination by it. Since we're reversing the copies, we want
     # to filter the source instead.
     f = _forwardcopies(b, a)
     r = {}
     for k, v in sorted(pycompat.iteritems(f)):
         if match and not match(v):
             continue
         # remove copies
         if v in a:
             continue
         r[v] = k
     return r
 
 
 def pathcopies(x, y, match=None):
     """find {dst@y: src@x} copy mapping for directed compare"""
     repo = x._repo
     debug = repo.ui.debugflag and repo.ui.configbool(b'devel', b'debug.copies')
     if debug:
         repo.ui.debug(
             b'debug.copies: searching copies from %s to %s\n' % (x, y)
         )
     if x == y or not x or not y:
         return {}
     if y.rev() is None and x == y.p1():
         if debug:
             repo.ui.debug(b'debug.copies: search mode: dirstate\n')
         # short-circuit to avoid issues with merge states
         return _dirstatecopies(repo, match)
     a = y.ancestor(x)
     if a == x:
         if debug:
             repo.ui.debug(b'debug.copies: search mode: forward\n')
         copies = _forwardcopies(x, y, match=match)
     elif a == y:
         if debug:
             repo.ui.debug(b'debug.copies: search mode: backward\n')
         copies = _backwardrenames(x, y, match=match)
     else:
         if debug:
             repo.ui.debug(b'debug.copies: search mode: combined\n')
         base = None
         if a.rev() != nullrev:
             base = x
         copies = _chain(
             _backwardrenames(x, a, match=match),
             _forwardcopies(a, y, base, match=match),
         )
     _filter(x, y, copies)
     return copies
 
 
 def mergecopies(repo, c1, c2, base):
     """
     Finds moves and copies between context c1 and c2 that are relevant for
     merging. 'base' will be used as the merge base.
 
     Copytracing is used in commands like rebase, merge, unshelve, etc to merge
     files that were moved/ copied in one merge parent and modified in another.
     For example:
 
     o          ---> 4 another commit
     |
     |   o      ---> 3 commit that modifies a.txt
     |  /
     o /        ---> 2 commit that moves a.txt to b.txt
     |/
     o          ---> 1 merge base
 
     If we try to rebase revision 3 on revision 4, since there is no a.txt in
     revision 4, and if user have copytrace disabled, we prints the following
     message:
 
     ```other changed <file> which local deleted```
 
     Returns a tuple where:
 
     "branch_copies" an instance of branch_copies.
 
     "diverge" is a mapping of source name -> list of destination names
     for divergent renames.
 
     This function calls different copytracing algorithms based on config.
     """
     # avoid silly behavior for update from empty dir
     if not c1 or not c2 or c1 == c2:
         return branch_copies(), branch_copies(), {}
 
     narrowmatch = c1.repo().narrowmatch()
 
     # avoid silly behavior for parent -> working dir
     if c2.node() is None and c1.node() == repo.dirstate.p1():
         return (
             branch_copies(_dirstatecopies(repo, narrowmatch)),
             branch_copies(),
             {},
         )
 
     copytracing = repo.ui.config(b'experimental', b'copytrace')
     if stringutil.parsebool(copytracing) is False:
         # stringutil.parsebool() returns None when it is unable to parse the
         # value, so we should rely on making sure copytracing is on such cases
         return branch_copies(), branch_copies(), {}
 
     if usechangesetcentricalgo(repo):
         # The heuristics don't make sense when we need changeset-centric algos
         return _fullcopytracing(repo, c1, c2, base)
 
     # Copy trace disabling is explicitly below the node == p1 logic above
     # because the logic above is required for a simple copy to be kept across a
     # rebase.
     if copytracing == b'heuristics':
         # Do full copytracing if only non-public revisions are involved as
         # that will be fast enough and will also cover the copies which could
         # be missed by heuristics
         if _isfullcopytraceable(repo, c1, base):
             return _fullcopytracing(repo, c1, c2, base)
         return _heuristicscopytracing(repo, c1, c2, base)
     else:
         return _fullcopytracing(repo, c1, c2, base)
 
 
 def _isfullcopytraceable(repo, c1, base):
     """Checks that if base, source and destination are all no-public branches,
     if yes let's use the full copytrace algorithm for increased capabilities
     since it will be fast enough.
 
     `experimental.copytrace.sourcecommitlimit` can be used to set a limit for
     number of changesets from c1 to base such that if number of changesets are
     more than the limit, full copytracing algorithm won't be used.
     """
     if c1.rev() is None:
         c1 = c1.p1()
     if c1.mutable() and base.mutable():
         sourcecommitlimit = repo.ui.configint(
             b'experimental', b'copytrace.sourcecommitlimit'
         )
         commits = len(repo.revs(b'%d::%d', base.rev(), c1.rev()))
         return commits < sourcecommitlimit
     return False
 
 
 def _checksinglesidecopies(
     src, dsts1, m1, m2, mb, c2, base, copy, renamedelete
 ):
     if src not in m2:
         # deleted on side 2
         if src not in m1:
             # renamed on side 1, deleted on side 2
             renamedelete[src] = dsts1
     elif src not in mb:
         # Work around the "short-circuit to avoid issues with merge states"
         # thing in pathcopies(): pathcopies(x, y) can return a copy where the
         # destination doesn't exist in y.
         pass
     elif mb[src] != m2[src] and not _related(c2[src], base[src]):
         return
     elif mb[src] != m2[src] or mb.flags(src) != m2.flags(src):
         # modified on side 2
         for dst in dsts1:
             copy[dst] = src
 
 
 class branch_copies(object):
     """Information about copies made on one side of a merge/graft.
 
     "copy" is a mapping from destination name -> source name,
     where source is in c1 and destination is in c2 or vice-versa.
 
     "movewithdir" is a mapping from source name -> destination name,
     where the file at source present in one context but not the other
     needs to be moved to destination by the merge process, because the
     other context moved the directory it is in.
 
     "renamedelete" is a mapping of source name -> list of destination
     names for files deleted in c1 that were renamed in c2 or vice-versa.
 
     "dirmove" is a mapping of detected source dir -> destination dir renames.
     This is needed for handling changes to new files previously grafted into
     renamed directories.
     """
 
     def __init__(
         self, copy=None, renamedelete=None, dirmove=None, movewithdir=None
     ):
         self.copy = {} if copy is None else copy
         self.renamedelete = {} if renamedelete is None else renamedelete
         self.dirmove = {} if dirmove is None else dirmove
         self.movewithdir = {} if movewithdir is None else movewithdir
 
     def __repr__(self):
         return '<branch_copies\n  copy=%r\n  renamedelete=%r\n  dirmove=%r\n  movewithdir=%r\n>' % (
             self.copy,
             self.renamedelete,
             self.dirmove,
             self.movewithdir,
         )
 
 
 def _fullcopytracing(repo, c1, c2, base):
     """The full copytracing algorithm which finds all the new files that were
     added from merge base up to the top commit and for each file it checks if
     this file was copied from another file.
 
     This is pretty slow when a lot of changesets are involved but will track all
     the copies.
     """
     m1 = c1.manifest()
     m2 = c2.manifest()
     mb = base.manifest()
 
     copies1 = pathcopies(base, c1)
     copies2 = pathcopies(base, c2)
 
     if not (copies1 or copies2):
         return branch_copies(), branch_copies(), {}
 
     inversecopies1 = {}
     inversecopies2 = {}
     for dst, src in copies1.items():
         inversecopies1.setdefault(src, []).append(dst)
     for dst, src in copies2.items():
         inversecopies2.setdefault(src, []).append(dst)
 
     copy1 = {}
     copy2 = {}
     diverge = {}
     renamedelete1 = {}
     renamedelete2 = {}
     allsources = set(inversecopies1) | set(inversecopies2)
     for src in allsources:
         dsts1 = inversecopies1.get(src)
         dsts2 = inversecopies2.get(src)
         if dsts1 and dsts2:
             # copied/renamed on both sides
             if src not in m1 and src not in m2:
                 # renamed on both sides
                 dsts1 = set(dsts1)
                 dsts2 = set(dsts2)
                 # If there's some overlap in the rename destinations, we
                 # consider it not divergent. For example, if side 1 copies 'a'
                 # to 'b' and 'c' and deletes 'a', and side 2 copies 'a' to 'c'
                 # and 'd' and deletes 'a'.
                 if dsts1 & dsts2:
                     for dst in dsts1 & dsts2:
                         copy1[dst] = src
                         copy2[dst] = src
                 else:
                     diverge[src] = sorted(dsts1 | dsts2)
             elif src in m1 and src in m2:
                 # copied on both sides
                 dsts1 = set(dsts1)
                 dsts2 = set(dsts2)
                 for dst in dsts1 & dsts2:
                     copy1[dst] = src
                     copy2[dst] = src
             # TODO: Handle cases where it was renamed on one side and copied
             # on the other side
         elif dsts1:
             # copied/renamed only on side 1
             _checksinglesidecopies(
                 src, dsts1, m1, m2, mb, c2, base, copy1, renamedelete1
             )
         elif dsts2:
             # copied/renamed only on side 2
             _checksinglesidecopies(
                 src, dsts2, m2, m1, mb, c1, base, copy2, renamedelete2
             )
 
     # find interesting file sets from manifests
     cache = []
 
     def _get_addedfiles(idx):
         if not cache:
             addedinm1 = m1.filesnotin(mb, repo.narrowmatch())
             addedinm2 = m2.filesnotin(mb, repo.narrowmatch())
             u1 = sorted(addedinm1 - addedinm2)
             u2 = sorted(addedinm2 - addedinm1)
             cache.extend((u1, u2))
         return cache[idx]
 
     u1fn = lambda: _get_addedfiles(0)
     u2fn = lambda: _get_addedfiles(1)
     if repo.ui.debugflag:
         u1 = u1fn()
         u2 = u2fn()
 
         header = b"  unmatched files in %s"
         if u1:
             repo.ui.debug(
                 b"%s:\n   %s\n" % (header % b'local', b"\n   ".join(u1))
             )
         if u2:
             repo.ui.debug(
                 b"%s:\n   %s\n" % (header % b'other', b"\n   ".join(u2))
             )
 
         renamedeleteset = set()
         divergeset = set()
         for dsts in diverge.values():
             divergeset.update(dsts)
         for dsts in renamedelete1.values():
             renamedeleteset.update(dsts)
         for dsts in renamedelete2.values():
             renamedeleteset.update(dsts)
 
         repo.ui.debug(
             b"  all copies found (* = to merge, ! = divergent, "
             b"% = renamed and deleted):\n"
         )
         for side, copies in ((b"local", copies1), (b"remote", copies2)):
             if not copies:
                 continue
             repo.ui.debug(b"   on %s side:\n" % side)
             for f in sorted(copies):
                 note = b""
                 if f in copy1 or f in copy2:
                     note += b"*"
                 if f in divergeset:
                     note += b"!"
                 if f in renamedeleteset:
                     note += b"%"
                 repo.ui.debug(
                     b"    src: '%s' -> dst: '%s' %s\n" % (copies[f], f, note)
                 )
         del renamedeleteset
         del divergeset
 
     repo.ui.debug(b"  checking for directory renames\n")
 
     dirmove1, movewithdir2 = _dir_renames(repo, c1, copy1, copies1, u2fn)
     dirmove2, movewithdir1 = _dir_renames(repo, c2, copy2, copies2, u1fn)
 
     branch_copies1 = branch_copies(copy1, renamedelete1, dirmove1, movewithdir1)
     branch_copies2 = branch_copies(copy2, renamedelete2, dirmove2, movewithdir2)
 
     return branch_copies1, branch_copies2, diverge
 
 
 def _dir_renames(repo, ctx, copy, fullcopy, addedfilesfn):
     """Finds moved directories and files that should move with them.
 
     ctx: the context for one of the sides
     copy: files copied on the same side (as ctx)
     fullcopy: files copied on the same side (as ctx), including those that
               merge.manifestmerge() won't care about
     addedfilesfn: function returning added files on the other side (compared to
                   ctx)
     """
     # generate a directory move map
     invalid = set()
     dirmove = {}
 
     # examine each file copy for a potential directory move, which is
     # when all the files in a directory are moved to a new directory
     for dst, src in pycompat.iteritems(fullcopy):
         dsrc, ddst = pathutil.dirname(src), pathutil.dirname(dst)
         if dsrc in invalid:
             # already seen to be uninteresting
             continue
         elif ctx.hasdir(dsrc) and ctx.hasdir(ddst):
             # directory wasn't entirely moved locally
             invalid.add(dsrc)
         elif dsrc in dirmove and dirmove[dsrc] != ddst:
             # files from the same directory moved to two different places
             invalid.add(dsrc)
         else:
             # looks good so far
             dirmove[dsrc] = ddst
 
     for i in invalid:
         if i in dirmove:
             del dirmove[i]
     del invalid
 
     if not dirmove:
         return {}, {}
 
     dirmove = {k + b"/": v + b"/" for k, v in pycompat.iteritems(dirmove)}
 
     for d in dirmove:
         repo.ui.debug(
             b"   discovered dir src: '%s' -> dst: '%s'\n" % (d, dirmove[d])
         )
 
     movewithdir = {}
     # check unaccounted nonoverlapping files against directory moves
     for f in addedfilesfn():
         if f not in fullcopy:
             for d in dirmove:
                 if f.startswith(d):
                     # new file added in a directory that was moved, move it
                     df = dirmove[d] + f[len(d) :]
                     if df not in copy:
                         movewithdir[f] = df
                         repo.ui.debug(
                             b"   pending file src: '%s' -> dst: '%s'\n"
                             % (f, df)
                         )
                     break
 
     return dirmove, movewithdir
 
 
 def _heuristicscopytracing(repo, c1, c2, base):
     """Fast copytracing using filename heuristics
 
     Assumes that moves or renames are of following two types:
 
     1) Inside a directory only (same directory name but different filenames)
     2) Move from one directory to another
                     (same filenames but different directory names)
 
     Works only when there are no merge commits in the "source branch".
     Source branch is commits from base up to c2 not including base.
 
     If merge is involved it fallbacks to _fullcopytracing().
 
     Can be used by setting the following config:
 
         [experimental]
         copytrace = heuristics
 
     In some cases the copy/move candidates found by heuristics can be very large
     in number and that will make the algorithm slow. The number of possible
     candidates to check can be limited by using the config
     `experimental.copytrace.movecandidateslimit` which defaults to 100.
     """
 
     if c1.rev() is None:
         c1 = c1.p1()
     if c2.rev() is None:
         c2 = c2.p1()
 
     changedfiles = set()
     m1 = c1.manifest()
     if not repo.revs(b'%d::%d', base.rev(), c2.rev()):
         # If base is not in c2 branch, we switch to fullcopytracing
         repo.ui.debug(
             b"switching to full copytracing as base is not "
             b"an ancestor of c2\n"
         )
         return _fullcopytracing(repo, c1, c2, base)
 
     ctx = c2
     while ctx != base:
         if len(ctx.parents()) == 2:
             # To keep things simple let's not handle merges
             repo.ui.debug(b"switching to full copytracing because of merges\n")
             return _fullcopytracing(repo, c1, c2, base)
         changedfiles.update(ctx.files())
         ctx = ctx.p1()
 
     copies2 = {}
     cp = _forwardcopies(base, c2)
     for dst, src in pycompat.iteritems(cp):
         if src in m1:
             copies2[dst] = src
 
     # file is missing if it isn't present in the destination, but is present in
     # the base and present in the source.
     # Presence in the base is important to exclude added files, presence in the
     # source is important to exclude removed files.
     filt = lambda f: f not in m1 and f in base and f in c2
     missingfiles = [f for f in changedfiles if filt(f)]
 
     copies1 = {}
     if missingfiles:
         basenametofilename = collections.defaultdict(list)
         dirnametofilename = collections.defaultdict(list)
 
         for f in m1.filesnotin(base.manifest()):
             basename = os.path.basename(f)
             dirname = os.path.dirname(f)
             basenametofilename[basename].append(f)
             dirnametofilename[dirname].append(f)
 
         for f in missingfiles:
             basename = os.path.basename(f)
             dirname = os.path.dirname(f)
             samebasename = basenametofilename[basename]
             samedirname = dirnametofilename[dirname]
             movecandidates = samebasename + samedirname
             # f is guaranteed to be present in c2, that's why
             # c2.filectx(f) won't fail
             f2 = c2.filectx(f)
             # we can have a lot of candidates which can slow down the heuristics
             # config value to limit the number of candidates moves to check
             maxcandidates = repo.ui.configint(
                 b'experimental', b'copytrace.movecandidateslimit'
             )
 
             if len(movecandidates) > maxcandidates:
                 repo.ui.status(
                     _(
                         b"skipping copytracing for '%s', more "
                         b"candidates than the limit: %d\n"
                     )
                     % (f, len(movecandidates))
                 )
                 continue
 
             for candidate in movecandidates:
                 f1 = c1.filectx(candidate)
                 if _related(f1, f2):
                     # if there are a few related copies then we'll merge
                     # changes into all of them. This matches the behaviour
                     # of upstream copytracing
                     copies1[candidate] = f
 
     return branch_copies(copies1), branch_copies(copies2), {}
 
 
 def _related(f1, f2):
     """return True if f1 and f2 filectx have a common ancestor
 
     Walk back to common ancestor to see if the two files originate
     from the same file. Since workingfilectx's rev() is None it messes
     up the integer comparison logic, hence the pre-step check for
     None (f1 and f2 can only be workingfilectx's initially).
     """
 
     if f1 == f2:
         return True  # a match
 
     g1, g2 = f1.ancestors(), f2.ancestors()
     try:
         f1r, f2r = f1.linkrev(), f2.linkrev()
 
         if f1r is None:
             f1 = next(g1)
         if f2r is None:
             f2 = next(g2)
 
         while True:
             f1r, f2r = f1.linkrev(), f2.linkrev()
             if f1r > f2r:
                 f1 = next(g1)
             elif f2r > f1r:
                 f2 = next(g2)
             else:  # f1 and f2 point to files in the same linkrev
                 return f1 == f2  # true if they point to the same file
     except StopIteration:
         return False
 
 
 def graftcopies(wctx, ctx, base):
     """reproduce copies between base and ctx in the wctx
 
     Unlike mergecopies(), this function will only consider copies between base
     and ctx; it will ignore copies between base and wctx. Also unlike
     mergecopies(), this function will apply copies to the working copy (instead
     of just returning information about the copies). That makes it cheaper
     (especially in the common case of base==ctx.p1()) and useful also when
     experimental.copytrace=off.
 
     merge.update() will have already marked most copies, but it will only
     mark copies if it thinks the source files are related (see
     merge._related()). It will also not mark copies if the file wasn't modified
     on the local side. This function adds the copies that were "missed"
     by merge.update().
     """
     new_copies = pathcopies(base, ctx)
     _filter(wctx.p1(), wctx, new_copies)
     for dst, src in pycompat.iteritems(new_copies):
         wctx[dst].markcopied(src)

tests/test-copies-chain-merge.t

@@ -1,1672 +1,1685 b''
 #testcases filelog compatibility changeset sidedata upgraded
 
 =====================================================
 Test Copy tracing for chain of copies involving merge
 =====================================================
 
 This test files covers copies/rename case for a chains of commit where merges
 are involved. It cheks we do not have unwanted update of behavior and that the
 different options to retrieve copies behave correctly.
 
 
 Setup
 =====
 
 use git diff to see rename
 
   $ cat << EOF >> $HGRCPATH
   > [diff]
   > git=yes
   > [command-templates]
   > log={rev} {desc}\n
   > EOF
 
 #if compatibility
   $ cat >> $HGRCPATH << EOF
   > [experimental]
   > copies.read-from = compatibility
   > EOF
 #endif
 
 #if changeset
   $ cat >> $HGRCPATH << EOF
   > [experimental]
   > copies.read-from = changeset-only
   > copies.write-to = changeset-only
   > EOF
 #endif
 
 #if sidedata
   $ cat >> $HGRCPATH << EOF
   > [format]
   > exp-use-side-data = yes
   > exp-use-copies-side-data-changeset = yes
   > EOF
 #endif
 
 
   $ hg init repo-chain
   $ cd repo-chain
 
 Add some linear rename initialy
 
   $ echo a > a
   $ echo b > b
   $ echo h > h
   $ hg ci -Am 'i-0 initial commit: a b h'
   adding a
   adding b
   adding h
   $ hg mv a c
   $ hg ci -Am 'i-1: a -move-> c'
   $ hg mv c d
   $ hg ci -Am 'i-2: c -move-> d'
   $ hg log -G
   @  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 And having another branch with renames on the other side
 
   $ hg mv d e
   $ hg ci -Am 'a-1: d -move-> e'
   $ hg mv e f
   $ hg ci -Am 'a-2: e -move-> f'
   $ hg log -G --rev '::.'
   @  4 a-2: e -move-> f
   |
   o  3 a-1: d -move-> e
   |
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 Have a branching with nothing on one side
 
   $ hg up 'desc("i-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ echo foo > b
   $ hg ci -m 'b-1: b update'
   created new head
   $ hg log -G --rev '::.'
   @  5 b-1: b update
   |
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 Create a branch that delete a file previous renamed
 
   $ hg up 'desc("i-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg rm d
   $ hg ci -m 'c-1 delete d'
   created new head
   $ hg log -G --rev '::.'
   @  6 c-1 delete d
   |
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 Create a branch that delete a file previous renamed and recreate it
 
   $ hg up 'desc("i-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg rm d
   $ hg ci -m 'd-1 delete d'
   created new head
   $ echo bar > d
   $ hg add d
   $ hg ci -m 'd-2 re-add d'
   $ hg log -G --rev '::.'
   @  8 d-2 re-add d
   |
   o  7 d-1 delete d
   |
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 Having another branch renaming a different file to the same filename as another
 
   $ hg up 'desc("i-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg mv b g
   $ hg ci -m 'e-1 b -move-> g'
   created new head
   $ hg mv g f
   $ hg ci -m 'e-2 g -move-> f'
   $ hg log -G --rev '::.'
   @  10 e-2 g -move-> f
   |
   o  9 e-1 b -move-> g
   |
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 Setup all merge
 ===============
 
 This is done beforehand to validate that the upgrade process creates valid copy
 information.
 
 merging with unrelated change does not interfere with the renames
 ---------------------------------------------------------------
 
 - rename on one side
 - unrelated change on the other side
 
   $ hg up 'desc("b-1")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("a-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mBAm-0 simple merge - one way'
   $ hg up 'desc("a-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mABm-0 simple merge - the other way'
   created new head
   $ hg log -G --rev '::(desc("mABm")+desc("mBAm"))'
   @    12 mABm-0 simple merge - the other way
   |\
   +---o  11 mBAm-0 simple merge - one way
   | |/
   | o  5 b-1: b update
   | |
   o |  4 a-2: e -move-> f
   | |
   o |  3 a-1: d -move-> e
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 
 merging with the side having a delete
 -------------------------------------
 
 case summary:
 - one with change to an unrelated file
 - one deleting the change
 and recreate an unrelated file after the merge
 
   $ hg up 'desc("b-1")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("c-1")'
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mBCm-0 simple merge - one way'
   $ echo bar > d
   $ hg add d
   $ hg ci -m 'mBCm-1 re-add d'
   $ hg up 'desc("c-1")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mCBm-0 simple merge - the other way'
   created new head
   $ echo bar > d
   $ hg add d
   $ hg ci -m 'mCBm-1 re-add d'
   $ hg log -G --rev '::(desc("mCBm")+desc("mBCm"))'
   @  16 mCBm-1 re-add d
   |
   o    15 mCBm-0 simple merge - the other way
   |\
   | | o  14 mBCm-1 re-add d
   | | |
   +---o  13 mBCm-0 simple merge - one way
   | |/
   | o  6 c-1 delete d
   | |
   o |  5 b-1: b update
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 Comparing with a merge re-adding the file afterward
 ---------------------------------------------------
 
 Merge:
 - one with change to an unrelated file
 - one deleting and recreating the change
 
   $ hg up 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("d-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mBDm-0 simple merge - one way'
   $ hg up 'desc("d-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mDBm-0 simple merge - the other way'
   created new head
   $ hg log -G --rev '::(desc("mDBm")+desc("mBDm"))'
   @    18 mDBm-0 simple merge - the other way
   |\
   +---o  17 mBDm-0 simple merge - one way
   | |/
   | o  8 d-2 re-add d
   | |
   | o  7 d-1 delete d
   | |
   o |  5 b-1: b update
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 
 Comparing with a merge with colliding rename
 --------------------------------------------
 
 - the "e-" branch renaming b to f (through 'g')
 - the "a-" branch renaming d to f (through e)
 
   $ hg up 'desc("a-2")'
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("e-2")' --tool :union
   merging f
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mAEm-0 simple merge - one way'
   $ hg up 'desc("e-2")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("a-2")' --tool :union
   merging f
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mEAm-0 simple merge - the other way'
   created new head
   $ hg log -G --rev '::(desc("mAEm")+desc("mEAm"))'
   @    20 mEAm-0 simple merge - the other way
   |\
   +---o  19 mAEm-0 simple merge - one way
   | |/
   | o  10 e-2 g -move-> f
   | |
   | o  9 e-1 b -move-> g
   | |
   o |  4 a-2: e -move-> f
   | |
   o |  3 a-1: d -move-> e
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 
 Merge:
 - one with change to an unrelated file (b)
 - one overwriting a file (d) with a rename (from h to i to d)
 
   $ hg up 'desc("i-2")'
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg mv h i
   $ hg commit -m "f-1: rename h -> i"
   created new head
   $ hg mv --force i d
   $ hg commit -m "f-2: rename i -> d"
   $ hg debugindex d
      rev linkrev nodeid       p1           p2
        0       2 169be882533b 000000000000 000000000000 (no-changeset !)
        0       2 b789fdd96dc2 000000000000 000000000000 (changeset !)
        1       8 b004912a8510 000000000000 000000000000
        2      22 4a067cf8965d 000000000000 000000000000 (no-changeset !)
        2      22 fe6f8b4f507f 000000000000 000000000000 (changeset !)
   $ hg up 'desc("b-1")'
   3 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("f-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mBFm-0 simple merge - one way'
   $ hg up 'desc("f-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mFBm-0 simple merge - the other way'
   created new head
   $ hg log -G --rev '::(desc("mBFm")+desc("mFBm"))'
   @    24 mFBm-0 simple merge - the other way
   |\
   +---o  23 mBFm-0 simple merge - one way
   | |/
   | o  22 f-2: rename i -> d
   | |
   | o  21 f-1: rename h -> i
   | |
   o |  5 b-1: b update
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 
 Merge:
 - one with change to a file
 - one deleting and recreating the file
 
 Unlike in the 'BD/DB' cases, an actual merge happened here. So we should
 consider history and rename on both branch of the merge.
 
   $ hg up 'desc("i-2")'
   3 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ echo "some update" >> d
   $ hg commit -m "g-1: update d"
   created new head
   $ hg up 'desc("d-2")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("g-1")' --tool :union
   merging d
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mDGm-0 simple merge - one way'
   $ hg up 'desc("g-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("d-2")' --tool :union
   merging d
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mGDm-0 simple merge - the other way'
   created new head
   $ hg log -G --rev '::(desc("mDGm")+desc("mGDm"))'
   @    27 mGDm-0 simple merge - the other way
   |\
   +---o  26 mDGm-0 simple merge - one way
   | |/
   | o  25 g-1: update d
   | |
   o |  8 d-2 re-add d
   | |
   o |  7 d-1 delete d
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 
 Merge:
 - one with change to a file (d)
 - one overwriting that file with a rename (from h to i, to d)
 
 This case is similar to BF/FB, but an actual merge happens, so both side of the
 history are relevant.
 
 Note:
 | In this case, the merge get conflicting information since on one side we have
 | "a -> c -> d". and one the other one we have "h -> i -> d".
 |
 | The current code arbitrarily pick one side
 
   $ hg up 'desc("f-2")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("g-1")' --tool :union
   merging d
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mFGm-0 simple merge - one way'
   created new head
   $ hg up 'desc("g-1")'
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("f-2")' --tool :union
   merging d
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m 'mGFm-0 simple merge - the other way'
   created new head
   $ hg log -G --rev '::(desc("mGFm")+desc("mFGm"))'
   @    29 mGFm-0 simple merge - the other way
   |\
   +---o  28 mFGm-0 simple merge - one way
   | |/
   | o  25 g-1: update d
   | |
   o |  22 f-2: rename i -> d
   | |
   o |  21 f-1: rename h -> i
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 
 Comparing with merging with a deletion (and keeping the file)
 -------------------------------------------------------------
 
 Merge:
 - one removing a file (d)
 - one updating that file
 - the merge keep the modified version of the file (canceling the delete)
 
 In this case, the file keep on living after the merge. So we should not drop its
 copy tracing chain.
 
   $ hg up 'desc("c-1")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("g-1")'
   file 'd' was deleted in local [working copy] but was modified in other [merge rev].
   You can use (c)hanged version, leave (d)eleted, or leave (u)nresolved.
   What do you want to do? u
   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 resolve -t :other d
   (no more unresolved files)
   $ hg ci -m "mCGm-0"
   created new head
 
   $ hg up 'desc("g-1")'
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("c-1")'
   file 'd' was deleted in other [merge rev] but was modified in local [working copy].
   You can use (c)hanged version, (d)elete, or leave (u)nresolved.
   What do you want to do? u
   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 resolve -t :local d
   (no more unresolved files)
   $ hg ci -m "mGCm-0"
   created new head
 
   $ hg log -G --rev '::(desc("mCGm")+desc("mGCm"))'
   @    31 mGCm-0
   |\
   +---o  30 mCGm-0
   | |/
   | o  25 g-1: update d
   | |
   o |  6 c-1 delete d
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 
 
 Comparing with merge restoring an untouched deleted file
 --------------------------------------------------------
 
 Merge:
 - one removing a file (d)
 - one leaving the file untouched
 - the merge actively restore the file to the same content.
 
 In this case, the file keep on living after the merge. So we should not drop its
 copy tracing chain.
 
   $ hg up 'desc("c-1")'
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg merge 'desc("b-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg revert --rev 'desc("b-1")' d
   $ hg ci -m "mCB-revert-m-0"
   created new head
 
   $ hg up 'desc("b-1")'
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("c-1")'
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg revert --rev 'desc("b-1")' d
   $ hg ci -m "mBC-revert-m-0"
   created new head
 
   $ hg log -G --rev '::(desc("mCB-revert-m")+desc("mBC-revert-m"))'
   @    33 mBC-revert-m-0
   |\
   +---o  32 mCB-revert-m-0
   | |/
   | o  6 c-1 delete d
   | |
   o |  5 b-1: b update
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 
   $ hg up null --quiet
 
 Merging a branch where a rename was deleted with a branch where the same file was renamed
 ------------------------------------------------------------------------------------------
 
 Create a "conflicting" merge where `d` get removed on one branch before its
 rename information actually conflict with the other branch.
 
 (the copy information from the branch that was not deleted should win).
 
   $ hg up 'desc("i-0")'
   3 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg mv b d
   $ hg ci -m "h-1: b -(move)-> d"
   created new head
 
   $ hg up 'desc("c-1")'
   1 files updated, 0 files merged, 2 files removed, 0 files unresolved
   $ hg merge 'desc("h-1")'
   1 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mCH-delete-before-conflict-m-0"
 
   $ hg up 'desc("h-1")'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg merge 'desc("c-1")'
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg ci -m "mHC-delete-before-conflict-m-0"
   created new head
   $ hg log -G --rev '::(desc("mCH-delete-before-conflict-m")+desc("mHC-delete-before-conflict-m"))'
   @    36 mHC-delete-before-conflict-m-0
   |\
   +---o  35 mCH-delete-before-conflict-m-0
   | |/
   | o  34 h-1: b -(move)-> d
   | |
   o |  6 c-1 delete d
   | |
   o |  2 i-2: c -move-> d
   | |
   o |  1 i-1: a -move-> c
   |/
   o  0 i-0 initial commit: a b h
   
 
 
 Test that sidedata computations during upgrades are correct
 ===========================================================
 
 We upgrade a repository that is not using sidedata (the filelog case) and
  check that the same side data have been generated as if they were computed at
  commit time.
 
 
 #if upgraded
   $ cat >> $HGRCPATH << EOF
   > [format]
   > exp-use-side-data = yes
   > exp-use-copies-side-data-changeset = yes
   > EOF
   $ hg debugformat -v
   format-variant     repo config default
   fncache:            yes    yes     yes
   dotencode:          yes    yes     yes
   generaldelta:       yes    yes     yes
   exp-sharesafe:       no     no      no
   sparserevlog:       yes    yes     yes
   sidedata:            no    yes      no
   persistent-nodemap:  no     no      no
   copies-sdc:          no    yes      no
   plain-cl-delta:     yes    yes     yes
   compression:        * (glob)
   compression-level:  default default default
   $ hg debugupgraderepo --run --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: * (glob)
      added: exp-copies-sidedata-changeset, exp-sidedata-flag
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
 #endif
 
 
 #if no-compatibility no-filelog no-changeset
 
   $ for rev in `hg log --rev 'all()' -T '{rev}\n'`; do
   >     echo "##### revision $rev #####"
   >     hg debugsidedata -c -v -- $rev
   >     hg debugchangedfiles $rev
   > done
   ##### revision 0 #####
   1 sidedata entries
    entry-0014 size 34
     '\x00\x00\x00\x03\x04\x00\x00\x00\x01\x00\x00\x00\x00\x04\x00\x00\x00\x02\x00\x00\x00\x00\x04\x00\x00\x00\x03\x00\x00\x00\x00abh'
   added      : a, ;
   added      : b, ;
   added      : h, ;
   ##### revision 1 #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00ac'
   removed    : a, ;
   added    p1: c, a;
   ##### revision 2 #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00cd'
   removed    : c, ;
   added    p1: d, c;
   ##### revision 3 #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00de'
   removed    : d, ;
   added    p1: e, d;
   ##### revision 4 #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00ef'
   removed    : e, ;
   added    p1: f, e;
   ##### revision 5 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x14\x00\x00\x00\x01\x00\x00\x00\x00b'
   touched    : b, ;
   ##### revision 6 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x0c\x00\x00\x00\x01\x00\x00\x00\x00d'
   removed    : d, ;
   ##### revision 7 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x0c\x00\x00\x00\x01\x00\x00\x00\x00d'
   removed    : d, ;
   ##### revision 8 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x04\x00\x00\x00\x01\x00\x00\x00\x00d'
   added      : d, ;
   ##### revision 9 #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00bg'
   removed    : b, ;
   added    p1: g, b;
   ##### revision 10 #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x06\x00\x00\x00\x01\x00\x00\x00\x01\x0c\x00\x00\x00\x02\x00\x00\x00\x00fg'
   added    p1: f, g;
   removed    : g, ;
   ##### revision 11 #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision 12 #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision 13 #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision 14 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x04\x00\x00\x00\x01\x00\x00\x00\x00d'
   added      : d, ;
   ##### revision 15 #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision 16 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x04\x00\x00\x00\x01\x00\x00\x00\x00d'
   added      : d, ;
   ##### revision 17 #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision 18 #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision 19 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00f'
   merged     : f, ;
   ##### revision 20 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00f'
   merged     : f, ;
   ##### revision 21 #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00hi'
   removed    : h, ;
   added    p1: i, h;
   ##### revision 22 #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x16\x00\x00\x00\x01\x00\x00\x00\x01\x0c\x00\x00\x00\x02\x00\x00\x00\x00di'
   touched  p1: d, i;
   removed    : i, ;
   ##### revision 23 #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision 24 #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision 25 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x14\x00\x00\x00\x01\x00\x00\x00\x00d'
   touched    : d, ;
   ##### revision 26 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00d'
   merged     : d, ;
   ##### revision 27 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00d'
   merged     : d, ;
   ##### revision 28 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00d'
   merged     : d, ;
   ##### revision 29 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x08\x00\x00\x00\x01\x00\x00\x00\x00d'
   merged     : d, ;
   ##### revision 30 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x10\x00\x00\x00\x01\x00\x00\x00\x00d'
   salvaged   : d, ;
   ##### revision 31 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x10\x00\x00\x00\x01\x00\x00\x00\x00d'
   salvaged   : d, ;
   ##### revision 32 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x10\x00\x00\x00\x01\x00\x00\x00\x00d'
   salvaged   : d, ;
   ##### revision 33 #####
   1 sidedata entries
    entry-0014 size 14
     '\x00\x00\x00\x01\x10\x00\x00\x00\x01\x00\x00\x00\x00d'
   salvaged   : d, ;
   ##### revision 34 #####
   1 sidedata entries
    entry-0014 size 24
     '\x00\x00\x00\x02\x0c\x00\x00\x00\x01\x00\x00\x00\x00\x06\x00\x00\x00\x02\x00\x00\x00\x00bd'
   removed    : b, ;
   added    p1: d, b;
   ##### revision 35 #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
   ##### revision 36 #####
   1 sidedata entries
    entry-0014 size 4
     '\x00\x00\x00\x00'
 
 #endif
 
 
 Test copy information chaining
 ==============================
 
+Check that matching only affect the destination and not intermediate path
+-------------------------------------------------------------------------
+
+The two status call should give the same value for f
+
+  $ hg status --copies --rev 'desc("i-0")' --rev 'desc("a-2")'
+  A f
+    a
+  R a
+  $ hg status --copies --rev 'desc("i-0")' --rev 'desc("a-2")' f
+  A f
+    a (no-changeset no-compatibility !)
+
 merging with unrelated change does not interfere with the renames
 ---------------------------------------------------------------
 
 - rename on one side
 - unrelated change on the other side
 
   $ hg log -G --rev '::(desc("mABm")+desc("mBAm"))'
   o    12 mABm-0 simple merge - the other way
   |\
   +---o  11 mBAm-0 simple merge - one way
   | |/
   | o  5 b-1: b update
   | |
   o |  4 a-2: e -move-> f
   | |
   o |  3 a-1: d -move-> e
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mABm")'
   A f
     d
   R d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBAm")'
   A f
     d
   R d
   $ hg status --copies --rev 'desc("a-2")' --rev 'desc("mABm")'
   M b
   $ hg status --copies --rev 'desc("a-2")' --rev 'desc("mBAm")'
   M b
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mABm")'
   M b
   A f
     d
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mBAm")'
   M b
   A f
     d
   R d
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mABm")'
   M b
   A f
     a
   R a
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBAm")'
   M b
   A f
     a
   R a
 
 merging with the side having a delete
 -------------------------------------
 
 case summary:
 - one with change to an unrelated file
 - one deleting the change
 and recreate an unrelated file after the merge
 
   $ hg log -G --rev '::(desc("mCBm")+desc("mBCm"))'
   o  16 mCBm-1 re-add d
   |
   o    15 mCBm-0 simple merge - the other way
   |\
   | | o  14 mBCm-1 re-add d
   | | |
   +---o  13 mBCm-0 simple merge - one way
   | |/
   | o  6 c-1 delete d
   | |
   o |  5 b-1: b update
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 - comparing from the merge
 
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBCm-0")'
   R d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mCBm-0")'
   R d
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mBCm-0")'
   M b
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mCBm-0")'
   M b
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mBCm-0")'
   M b
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mCBm-0")'
   M b
   R d
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBCm-0")'
   M b
   R a
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCBm-0")'
   M b
   R a
 
 - comparing with the merge children re-adding the file
 
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBCm-1")'
   M d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mCBm-1")'
   M d
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mBCm-1")'
   M b
   A d
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mCBm-1")'
   M b
   A d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mBCm-1")'
   M b
   M d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mCBm-1")'
   M b
   M d
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBCm-1")'
   M b
   A d
   R a
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCBm-1")'
   M b
   A d
   R a
 
 Comparing with a merge re-adding the file afterward
 ---------------------------------------------------
 
 Merge:
 - one with change to an unrelated file
 - one deleting and recreating the change
 
   $ hg log -G --rev '::(desc("mDBm")+desc("mBDm"))'
   o    18 mDBm-0 simple merge - the other way
   |\
   +---o  17 mBDm-0 simple merge - one way
   | |/
   | o  8 d-2 re-add d
   | |
   | o  7 d-1 delete d
   | |
   o |  5 b-1: b update
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBDm-0")'
   M d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mDBm-0")'
   M d
   $ hg status --copies --rev 'desc("d-2")' --rev 'desc("mBDm-0")'
   M b
   $ hg status --copies --rev 'desc("d-2")' --rev 'desc("mDBm-0")'
   M b
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mBDm-0")'
   M b
   M d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mDBm-0")'
   M b
   M d
 
 The bugs makes recorded copy is different depending of where we started the merge from since
 
   $ hg manifest --debug --rev 'desc("mBDm-0")' | grep '644   d'
   b004912a8510032a0350a74daa2803dadfb00e12 644   d
   $ hg manifest --debug --rev 'desc("mDBm-0")' | grep '644   d'
   b004912a8510032a0350a74daa2803dadfb00e12 644   d
 
   $ hg manifest --debug --rev 'desc("d-2")' | grep '644   d'
   b004912a8510032a0350a74daa2803dadfb00e12 644   d
   $ hg manifest --debug --rev 'desc("b-1")' | grep '644   d'
   169be882533bc917905d46c0c951aa9a1e288dcf 644   d (no-changeset !)
   b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3 644   d (changeset !)
   $ hg debugindex d | head -n 4
      rev linkrev nodeid       p1           p2
        0       2 169be882533b 000000000000 000000000000 (no-changeset !)
        0       2 b789fdd96dc2 000000000000 000000000000 (changeset !)
        1       8 b004912a8510 000000000000 000000000000
        2      22 4a067cf8965d 000000000000 000000000000 (no-changeset !)
        2      22 fe6f8b4f507f 000000000000 000000000000 (changeset !)
 
 Log output should not include a merge commit as it did not happen
 
   $ hg log -Gfr 'desc("mBDm-0")' d
   o  8 d-2 re-add d
   |
   ~
 
   $ hg log -Gfr 'desc("mDBm-0")' d
   o  8 d-2 re-add d
   |
   ~
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBDm-0")'
   M b
   A d
   R a
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mDBm-0")'
   M b
   A d
   R a
 
 
 Comparing with a merge with colliding rename
 --------------------------------------------
 
 - the "e-" branch renaming b to f (through 'g')
 - the "a-" branch renaming d to f (through e)
 
   $ hg log -G --rev '::(desc("mAEm")+desc("mEAm"))'
   o    20 mEAm-0 simple merge - the other way
   |\
   +---o  19 mAEm-0 simple merge - one way
   | |/
   | o  10 e-2 g -move-> f
   | |
   | o  9 e-1 b -move-> g
   | |
   o |  4 a-2: e -move-> f
   | |
   o |  3 a-1: d -move-> e
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 #if no-changeset
   $ hg manifest --debug --rev 'desc("mAEm-0")' | grep '644   f'
   c39c6083dad048d5138618a46f123e2f397f4f18 644   f
   $ hg manifest --debug --rev 'desc("mEAm-0")' | grep '644   f'
   a9a8bc3860c9d8fa5f2f7e6ea8d40498322737fd 644   f
   $ hg manifest --debug --rev 'desc("a-2")' | grep '644   f'
   263ea25e220aaeb7b9bac551c702037849aa75e8 644   f
   $ hg manifest --debug --rev 'desc("e-2")' | grep '644   f'
   71b9b7e73d973572ade6dd765477fcee6890e8b1 644   f
   $ hg debugindex f
      rev linkrev nodeid       p1           p2
        0       4 263ea25e220a 000000000000 000000000000
        1      10 71b9b7e73d97 000000000000 000000000000
        2      19 c39c6083dad0 263ea25e220a 71b9b7e73d97
        3      20 a9a8bc3860c9 71b9b7e73d97 263ea25e220a
 #else
   $ hg manifest --debug --rev 'desc("mAEm-0")' | grep '644   f'
   498e8799f49f9da1ca06bb2d6d4accf165c5b572 644   f
   $ hg manifest --debug --rev 'desc("mEAm-0")' | grep '644   f'
   c5b506a7118667a38a9c9348a1f63b679e382f57 644   f
   $ hg manifest --debug --rev 'desc("a-2")' | grep '644   f'
   b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3 644   f
   $ hg manifest --debug --rev 'desc("e-2")' | grep '644   f'
   1e88685f5ddec574a34c70af492f95b6debc8741 644   f
   $ hg debugindex f
      rev linkrev nodeid       p1           p2
        0       4 b789fdd96dc2 000000000000 000000000000
        1      10 1e88685f5dde 000000000000 000000000000
        2      19 498e8799f49f b789fdd96dc2 1e88685f5dde
        3      20 c5b506a71186 1e88685f5dde b789fdd96dc2
 #endif
 
 # Here the filelog based implementation is not looking at the rename
 # information (because the file exist on both side). However the changelog
 # based on works fine. We have different output.
 
   $ hg status --copies --rev 'desc("a-2")' --rev 'desc("mAEm-0")'
   M f
     b (no-filelog !)
   R b
   $ hg status --copies --rev 'desc("a-2")' --rev 'desc("mEAm-0")'
   M f
     b (no-filelog !)
   R b
   $ hg status --copies --rev 'desc("e-2")' --rev 'desc("mAEm-0")'
   M f
     d (no-filelog !)
   R d
   $ hg status --copies --rev 'desc("e-2")' --rev 'desc("mEAm-0")'
   M f
     d (no-filelog !)
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("a-2")'
   A f
     d
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("e-2")'
   A f
     b
   R b
 
 # From here, we run status against revision where both source file exists.
 #
 # The filelog based implementation picks an arbitrary side based on revision
 # numbers. So the same side "wins" whatever the parents order is. This is
 # sub-optimal because depending on revision numbers means the result can be
 # different from one repository to the next.
 #
 # The changeset based algorithm use the parent order to break tie on conflicting
 # information and will have a different order depending on who is p1 and p2.
 # That order is stable accross repositories. (data from p1 prevails)
 
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mAEm-0")'
   A f
     d
   R b
   R d
   $ hg status --copies --rev 'desc("i-2")' --rev 'desc("mEAm-0")'
   A f
     d (filelog !)
     b (no-filelog !)
   R b
   R d
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mAEm-0")'
   A f
     a
   R a
   R b
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mEAm-0")'
   A f
     a (filelog !)
     b (no-filelog !)
   R a
   R b
 
 
 Note:
 | In this case, one of the merge wrongly record a merge while there is none.
 | This lead to bad copy tracing information to be dug up.
 
 
 Merge:
 - one with change to an unrelated file (b)
 - one overwriting a file (d) with a rename (from h to i to d)
 
   $ hg log -G --rev '::(desc("mBFm")+desc("mFBm"))'
   o    24 mFBm-0 simple merge - the other way
   |\
   +---o  23 mBFm-0 simple merge - one way
   | |/
   | o  22 f-2: rename i -> d
   | |
   | o  21 f-1: rename h -> i
   | |
   o |  5 b-1: b update
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBFm-0")'
   M b
   A d
     h
   R a
   R h
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mFBm-0")'
   M b
   A d
     h
   R a
   R h
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBFm-0")'
   M d
     h (no-filelog !)
   R h
   $ hg status --copies --rev 'desc("f-2")' --rev 'desc("mBFm-0")'
   M b
   $ hg status --copies --rev 'desc("f-1")' --rev 'desc("mBFm-0")'
   M b
   M d
     i (no-filelog !)
   R i
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mFBm-0")'
   M d
     h (no-filelog !)
   R h
   $ hg status --copies --rev 'desc("f-2")' --rev 'desc("mFBm-0")'
   M b
   $ hg status --copies --rev 'desc("f-1")' --rev 'desc("mFBm-0")'
   M b
   M d
     i (no-filelog !)
   R i
 
 #if no-changeset
   $ hg log -Gfr 'desc("mBFm-0")' d
   o  22 f-2: rename i -> d
   |
   o  21 f-1: rename h -> i
   :
   o  0 i-0 initial commit: a b h
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mBFm-0")' d
   o  22 f-2: rename i -> d
   |
   ~
 #endif
 
 #if no-changeset
   $ hg log -Gfr 'desc("mFBm-0")' d
   o  22 f-2: rename i -> d
   |
   o  21 f-1: rename h -> i
   :
   o  0 i-0 initial commit: a b h
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mFBm-0")' d
   o  22 f-2: rename i -> d
   |
   ~
 #endif
 
 
 Merge:
 - one with change to a file
 - one deleting and recreating the file
 
 Unlike in the 'BD/DB' cases, an actual merge happened here. So we should
 consider history and rename on both branch of the merge.
 
   $ hg log -G --rev '::(desc("mDGm")+desc("mGDm"))'
   o    27 mGDm-0 simple merge - the other way
   |\
   +---o  26 mDGm-0 simple merge - one way
   | |/
   | o  25 g-1: update d
   | |
   o |  8 d-2 re-add d
   | |
   o |  7 d-1 delete d
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 One side of the merge have a long history with rename. The other side of the
 merge point to a new file with a smaller history. Each side is "valid".
 
 (and again the filelog based algorithm only explore one, with a pick based on
 revision numbers)
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mDGm-0")'
   A d
     a (filelog !)
   R a
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mGDm-0")'
   A d
     a
   R a
   $ hg status --copies --rev 'desc("d-2")' --rev 'desc("mDGm-0")'
   M d
   $ hg status --copies --rev 'desc("d-2")' --rev 'desc("mGDm-0")'
   M d
   $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mDGm-0")'
   M d
   $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mGDm-0")'
   M d
 
 #if no-changeset
   $ hg log -Gfr 'desc("mDGm-0")' d
   o    26 mDGm-0 simple merge - one way
   |\
   | o  25 g-1: update d
   | |
   o |  8 d-2 re-add d
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mDGm-0")' d
   o    26 mDGm-0 simple merge - one way
   |\
   | o  25 g-1: update d
   | |
   o |  8 d-2 re-add d
   |/
   o  2 i-2: c -move-> d
   |
   ~
 #endif
 
 
 #if no-changeset
   $ hg log -Gfr 'desc("mDGm-0")' d
   o    26 mDGm-0 simple merge - one way
   |\
   | o  25 g-1: update d
   | |
   o |  8 d-2 re-add d
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mDGm-0")' d
   o    26 mDGm-0 simple merge - one way
   |\
   | o  25 g-1: update d
   | |
   o |  8 d-2 re-add d
   |/
   o  2 i-2: c -move-> d
   |
   ~
 #endif
 
 
 Merge:
 - one with change to a file (d)
 - one overwriting that file with a rename (from h to i, to d)
 
 This case is similar to BF/FB, but an actual merge happens, so both side of the
 history are relevant.
 
 Note:
 | In this case, the merge get conflicting information since on one side we have
 | "a -> c -> d". and one the other one we have "h -> i -> d".
 |
 | The current code arbitrarily pick one side
 
   $ hg log -G --rev '::(desc("mGFm")+desc("mFGm"))'
   o    29 mGFm-0 simple merge - the other way
   |\
   +---o  28 mFGm-0 simple merge - one way
   | |/
   | o  25 g-1: update d
   | |
   o |  22 f-2: rename i -> d
   | |
   o |  21 f-1: rename h -> i
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mFGm-0")'
   A d
     h
   R a
   R h
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mGFm-0")'
   A d
     a (no-filelog !)
     h (filelog !)
   R a
   R h
   $ hg status --copies --rev 'desc("f-2")' --rev 'desc("mFGm-0")'
   M d
   $ hg status --copies --rev 'desc("f-2")' --rev 'desc("mGFm-0")'
   M d
   $ hg status --copies --rev 'desc("f-1")' --rev 'desc("mFGm-0")'
   M d
     i (no-filelog !)
   R i
   $ hg status --copies --rev 'desc("f-1")' --rev 'desc("mGFm-0")'
   M d
     i (no-filelog !)
   R i
   $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mFGm-0")'
   M d
     h (no-filelog !)
   R h
   $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mGFm-0")'
   M d
     h (no-filelog !)
   R h
 
 #if no-changeset
   $ hg log -Gfr 'desc("mFGm-0")' d
   o    28 mFGm-0 simple merge - one way
   |\
   | o  25 g-1: update d
   | |
   o |  22 f-2: rename i -> d
   | |
   o |  21 f-1: rename h -> i
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mFGm-0")' d
   o    28 mFGm-0 simple merge - one way
   |\
   | o  25 g-1: update d
   | |
   o |  22 f-2: rename i -> d
   |/
   o  2 i-2: c -move-> d
   |
   ~
 #endif
 
 #if no-changeset
   $ hg log -Gfr 'desc("mGFm-0")' d
   o    29 mGFm-0 simple merge - the other way
   |\
   | o  25 g-1: update d
   | |
   o |  22 f-2: rename i -> d
   | |
   o |  21 f-1: rename h -> i
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 #else
 BROKEN: `hg log --follow <file>` relies on filelog metadata to work
   $ hg log -Gfr 'desc("mGFm-0")' d
   o    29 mGFm-0 simple merge - the other way
   |\
   | o  25 g-1: update d
   | |
   o |  22 f-2: rename i -> d
   |/
   o  2 i-2: c -move-> d
   |
   ~
 #endif
 
 
 Comparing with merging with a deletion (and keeping the file)
 -------------------------------------------------------------
 
 Merge:
 - one removing a file (d)
 - one updating that file
 - the merge keep the modified version of the file (canceling the delete)
 
 In this case, the file keep on living after the merge. So we should not drop its
 copy tracing chain.
 
   $ hg log -G --rev '::(desc("mCGm")+desc("mGCm"))'
   o    31 mGCm-0
   |\
   +---o  30 mCGm-0
   | |/
   | o  25 g-1: update d
   | |
   o |  6 c-1 delete d
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 'a' is the copy source of 'd'
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCGm-0")'
   A d
     a (no-compatibility no-changeset !)
   R a
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mGCm-0")'
   A d
     a (no-compatibility no-changeset !)
   R a
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mCGm-0")'
   A d
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mGCm-0")'
   A d
   $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mCGm-0")'
   $ hg status --copies --rev 'desc("g-1")' --rev 'desc("mGCm-0")'
 
 
 Comparing with merge restoring an untouched deleted file
 --------------------------------------------------------
 
 Merge:
 - one removing a file (d)
 - one leaving the file untouched
 - the merge actively restore the file to the same content.
 
 In this case, the file keep on living after the merge. So we should not drop its
 copy tracing chain.
 
   $ hg log -G --rev '::(desc("mCB-revert-m")+desc("mBC-revert-m"))'
   o    33 mBC-revert-m-0
   |\
   +---o  32 mCB-revert-m-0
   | |/
   | o  6 c-1 delete d
   | |
   o |  5 b-1: b update
   |/
   o  2 i-2: c -move-> d
   |
   o  1 i-1: a -move-> c
   |
   o  0 i-0 initial commit: a b h
   
 
 'a' is the the copy source of 'd'
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCB-revert-m-0")'
   M b
   A d
     a (no-compatibility no-changeset !)
   R a
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mBC-revert-m-0")'
   M b
   A d
     a (no-compatibility no-changeset !)
   R a
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mCB-revert-m-0")'
   M b
   A d
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mBC-revert-m-0")'
   M b
   A d
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mCB-revert-m-0")'
   $ hg status --copies --rev 'desc("b-1")' --rev 'desc("mBC-revert-m-0")'
 
 
 Merging a branch where a rename was deleted with a branch where the same file was renamed
 ------------------------------------------------------------------------------------------
 
 Create a "conflicting" merge where `d` get removed on one branch before its
 rename information actually conflict with the other branch.
 
 (the copy information from the branch that was not deleted should win).
 
   $ hg log -G --rev '::(desc("mCH-delete-before-conflict-m")+desc("mHC-delete-before-conflict-m"))'
   @    36 mHC-delete-before-conflict-m-0
   |\
   +---o  35 mCH-delete-before-conflict-m-0
   | |/
   | o  34 h-1: b -(move)-> d
   | |
   o |  6 c-1 delete d
   | |
   o |  2 i-2: c -move-> d
   | |
   o |  1 i-1: a -move-> c
   |/
   o  0 i-0 initial commit: a b h
   
 
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mCH-delete-before-conflict-m")'
   A d
     b (no-compatibility no-changeset !)
   R a
   R b
   $ hg status --copies --rev 'desc("i-0")' --rev 'desc("mHC-delete-before-conflict-m")'
   A d
     b
   R a
   R b
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mCH-delete-before-conflict-m")'
   A d
     b
   R b
   $ hg status --copies --rev 'desc("c-1")' --rev 'desc("mHC-delete-before-conflict-m")'
   A d
     b
   R b
   $ hg status --copies --rev 'desc("h-1")' --rev 'desc("mCH-delete-before-conflict-m")'
   R a
   $ hg status --copies --rev 'desc("h-1")' --rev 'desc("mHC-delete-before-conflict-m")'
   R a