mercurial/localrepo.py

--- a/mercurial/localrepo.py	Thu Apr 16 11:31:48 2015 -0700
+++ b/mercurial/localrepo.py	Thu Apr 16 18:48:20 2015 -0500
@@ -1092,6 +1092,9 @@
             else:
                 ui.status(_('working directory now based on '
                             'revision %d\n') % parents)
+            ms = mergemod.mergestate(self)
+            ms.reset(self['.'].node())
+
         # TODO: if we know which new heads may result from this rollback, pass
         # them to destroy(), which will prevent the branchhead cache from being
         # invalidated.