Deal with merge abort more gracefully

We save parent info last rather than first.

mercurial/localrepo.py

@@ -1504,9 +1504,6 b' class localrepository:'
                 return 1
             branch_merge = True
 
-        if moddirstate:
-            self.dirstate.setparents(p1, p2)
-
         # get the files we don't need to change
         files = get.keys()
         files.sort()
@@ -1559,6 +1556,9 b' class localrepository:'
             else:
                 self.dirstate.forget(remove)
 
+        if moddirstate:
+            self.dirstate.setparents(p1, p2)
+
     def merge3(self, fn, my, other):
         """perform a 3-way merge in the working directory"""