D9415: copies: fast path no-op merge

[Alphare (Raphaël Gomès)]

Alphare created this revision.
Herald added a reviewer: hg-reviewers.
Herald added a subscriber: mercurial-patches.

REVISION SUMMARY
  If the two sides of the merge are the same (they come an unaltered common
  ancestors) we don't need any merging.

REPOSITORY
  rHG Mercurial

BRANCH
  default

REVISION DETAIL
  https://phab.mercurial-scm.org/D9415

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
@@ -391,6 +391,9 @@
             othercopies = all_copies.get(c)
             if othercopies is None:
                 all_copies[c] = newcopies
+            elif newcopies is othercopies:
+                # nothing to merge:
+                pass
             else:
                 # we are the second parent to work on c, we need to merge our
                 # work with the other.



To: Alphare, #hg-reviewers
Cc: mercurial-patches, mercurial-devel