diff -r a83110faece1 -r 69a121c378ef mercurial/localrepo.py
--- a/mercurial/localrepo.py	Thu Oct 15 00:57:56 2015 -0700
+++ b/mercurial/localrepo.py	Thu Oct 15 01:02:32 2015 -0700
@@ -1564,7 +1564,7 @@
             if unresolved:
                 raise error.Abort(_('unresolved merge conflicts '
                                     '(see "hg help resolve")'))
-            if driverresolved:
+            if driverresolved or ms.mdstate() != 's':
                 raise error.Abort(_('driver-resolved merge conflicts'),
                                   hint=_('run "hg resolve --all" to resolve'))