merge: remove files with extra actions from merge action list
See the comment for a detailed explanation why.
Even though this is a bug, I've sent it to 'default' rather than 'stable'
because it isn't triggered in any code paths in stock Mercurial, just with the
merge driver included. For the same reason I haven't included any tests here --
the merge driver is getting a new test.
--- a/mercurial/merge.py Mon Aug 22 21:48:50 2016 -0700
+++ b/mercurial/merge.py Tue Aug 23 17:58:53 2016 -0700
@@ -1286,8 +1286,29 @@
removed += msremoved
extraactions = ms.actions()
- for k, acts in extraactions.iteritems():
- actions[k].extend(acts)
+ if extraactions:
+ mfiles = set(a[0] for a in actions['m'])
+ for k, acts in extraactions.iteritems():
+ actions[k].extend(acts)
+ # Remove these files from actions['m'] as well. This is important
+ # because in recordupdates, files in actions['m'] are processed
+ # after files in other actions, and the merge driver might add
+ # files to those actions via extraactions above. This can lead to a
+ # file being recorded twice, with poor results. This is especially
+ # problematic for actions['r'] (currently only possible with the
+ # merge driver in the initial merge process; interrupted merges
+ # don't go through this flow).
+ #
+ # The real fix here is to have indexes by both file and action so
+ # that when the action for a file is changed it is automatically
+ # reflected in the other action lists. But that involves a more
+ # complex data structure, so this will do for now.
+ #
+ # We don't need to do the same operation for 'dc' and 'cd' because
+ # those lists aren't consulted again.
+ mfiles.difference_update(a[0] for a in acts)
+
+ actions['m'] = [a for a in actions['m'] if a[0] in mfiles]
progress(_updating, None, total=numupdates, unit=_files)