D6276: copies: clarify mutually exclusive cases in _chain() with a s/if/elif/

[martinvonz (Martin von Zweigbergk)]

martinvonz created this revision.
Herald added a subscriber: mercurial-devel.
Herald added a reviewer: hg-reviewers.

REVISION SUMMARY
  If the 'b' dict has a rename from 'x' to 'y', it shouldn't be possible
  for 'x' to be both (a key) in 'a' and in 'src'. That would mean that
  'x' is a file in the source commit and also a rename destination in
  the intermediate commit. But we currently don't allow renaming files
  onto existing files, so that shouldn't happen. So let's clarify that
  by using an "elif" instead of an "if". And if we did allow renaming
  files onto existing files, we should prefer to use the rename
  destination in the intermediate commit as source anyway.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D6276

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
@@ -134,7 +134,7 @@
             if t[v] != k:
                 # file wasn't renamed back to itself (i.e. case 4, not 3)
                 t[k] = t[v]
-        if v in src:
+        elif v in src:
             # file is a copy of an existing file, i.e. case 6.
             t[k] = v
 



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