# HG changeset patch
# User Ryan McElroy <rmcelroy@fb.com>
# Date 1507297723 25200
# Node ID c0a524f77e8afc61d2ebcd518ecf65955b4afb35
# Parent  143337bcec9b387d1cd81d5036cf871abf768055
merge: ensure that we always commit the mergestate

In future patches, we may halt the merge process based on configuration or
user requests by raising exceptions. We need to ensure that the mergestate
is unconditionally committed even when such an exception is raised.

Depends on D930.

Differential Revision: https://phab.mercurial-scm.org/D931

diff -r 143337bcec9b -r c0a524f77e8a mercurial/merge.py
--- a/mercurial/merge.py	Fri Oct 06 06:48:43 2017 -0700
+++ b/mercurial/merge.py	Fri Oct 06 06:48:43 2017 -0700
@@ -1537,30 +1537,32 @@
                 newactions.append((f, args, msg))
         mergeactions = newactions
 
-    # premerge
-    tocomplete = []
-    for f, args, msg in mergeactions:
-        repo.ui.debug(" %s: %s -> m (premerge)\n" % (f, msg))
-        z += 1
-        progress(_updating, z, item=f, total=numupdates, unit=_files)
-        if f == '.hgsubstate': # subrepo states need updating
-            subrepo.submerge(repo, wctx, mctx, wctx.ancestor(mctx),
-                             overwrite, labels)
-            continue
-        wctx[f].audit()
-        complete, r = ms.preresolve(f, wctx)
-        if not complete:
-            numupdates += 1
-            tocomplete.append((f, args, msg))
+    try:
+        # premerge
+        tocomplete = []
+        for f, args, msg in mergeactions:
+            repo.ui.debug(" %s: %s -> m (premerge)\n" % (f, msg))
+            z += 1
+            progress(_updating, z, item=f, total=numupdates, unit=_files)
+            if f == '.hgsubstate': # subrepo states need updating
+                subrepo.submerge(repo, wctx, mctx, wctx.ancestor(mctx),
+                                 overwrite, labels)
+                continue
+            wctx[f].audit()
+            complete, r = ms.preresolve(f, wctx)
+            if not complete:
+                numupdates += 1
+                tocomplete.append((f, args, msg))
 
-    # merge
-    for f, args, msg in tocomplete:
-        repo.ui.debug(" %s: %s -> m (merge)\n" % (f, msg))
-        z += 1
-        progress(_updating, z, item=f, total=numupdates, unit=_files)
-        ms.resolve(f, wctx)
+        # merge
+        for f, args, msg in tocomplete:
+            repo.ui.debug(" %s: %s -> m (merge)\n" % (f, msg))
+            z += 1
+            progress(_updating, z, item=f, total=numupdates, unit=_files)
+            ms.resolve(f, wctx)
 
-    ms.commit()
+    finally:
+        ms.commit()
 
     unresolved = ms.unresolvedcount()