D3896: copies: handle case when both merge cset are not descendant of merge base

[pulkit (Pulkit Goyal)]

pulkit created this revision.
Herald added a subscriber: mercurial-devel.
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REVISION SUMMARY
  There can be cases when both the changesets which we are merging are not
  descendants of the merge base. In those cases dirtyc1 and dirtyc2 both will be
  true. The existing code assumes that either of them will be true always but that
  is not a right assumption.
  
  I found this while working with content-divergence resolution. In
  content-divergence resolution, we use the common predecessor as the merge base
  for resolving content divergence and there it can be possible that the merge
  base is not the descendant of both the content-divergence changsets.
  
  The code in content-divergence which does this is at:
  https://www.mercurial-scm.org/repo/evolve/file/b81fd1487e04/hgext3rd/evolve/evolvecmd.py#l507

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D3896

AFFECTED FILES
  mercurial/copies.py

CHANGE DETAILS

diff --git a/mercurial/copies.py b/mercurial/copies.py
--- a/mercurial/copies.py
+++ b/mercurial/copies.py
@@ -532,7 +532,10 @@
     for f in bothnew:
         _checkcopies(c1, c2, f, base, tca, dirtyc1, limit, both1)
         _checkcopies(c2, c1, f, base, tca, dirtyc2, limit, both2)
-    if dirtyc1:
+
+    if dirtyc1 and dirtyc2:
+        pass
+    elif dirtyc1:
         # incomplete copies may only be found on the "dirty" side for bothnew
         assert not both2['incomplete']
         remainder = _combinecopies({}, both1['incomplete'], copy, bothdiverge,



To: pulkit, #hg-reviewers
Cc: mercurial-devel