diff mercurial/localrepo.py @ 44437:6a34e438461b

commit: clear resolved mergestate even if working copy is clean

If the mergestate has resolved conflicts and a commit is successfully
created (either because there are changes in the working copy or
because ui.allowemptycommit=yes), we will also clear the merge
state. However, if the working copy is clean (and
ui.allowemptycommit=no), we leave the mergestate there. The user may
notice it in `hg resolve -l` output (but not in `hg status -v`
output). It's not clear how the user should clear it, but probably via
`hg co -C .`. It's also quite likely that they won't even notice it
and it will get cleared by a later `hg commit` (of unrelated
changes).

This patch makes it so that `hg commit` also clears resolved merge
conflicts even if the command doesn't end up writing a commit because
the working copy was empty. That's probably a little weird (commands
that abort should generally avoid changing the repo), but it still
seems mostly harmless, and it reduces the risk of more bugs like
https://bz.mercurial-scm.org/show_bug.cgi?id=5494. I just ran into a
version of that bug in the Evolve extension and that's what triggered
this series.

Differential Revision: https://phab.mercurial-scm.org/D8196

--- a/mercurial/localrepo.py	Wed Mar 04 00:45:54 2020 -0500
+++ b/mercurial/localrepo.py	Fri Feb 28 11:32:02 2020 -0800
@@ -2956,6 +2956,7 @@
                 or self.ui.configbool(b'ui', b'allowemptycommit')
             )
             if not allowemptycommit:
+                ms.reset()
                 return None
 
             if merge and cctx.deleted():