diff -r b546db00cfd7 -r 84cec5895d01 mercurial/localrepo.py
--- a/mercurial/localrepo.py	Mon Dec 20 12:08:56 2010 -0600
+++ b/mercurial/localrepo.py	Fri Dec 17 13:38:15 2010 +0100
@@ -949,7 +949,6 @@
 
             # commit subs
             if subs or removedsubs:
-                pstate = subrepo.substate(self['.'])
                 state = wctx.substate.copy()
                 for s in sorted(subs):
                     sub = wctx.sub(s)
@@ -957,19 +956,7 @@
                         subrepo.subrelpath(sub))
                     sr = sub.commit(cctx._text, user, date)
                     state[s] = (state[s][0], sr)
-
-                changed = False
-                if len(pstate) != len(state):
-                    changed = True
-                if not changed:
-                    for newstate in state:
-                        if state[newstate][1] != pstate[newstate]:
-                            changed = True
-                if changed:
-                    subrepo.writestate(self, state)
-                elif (changes[0] == ['.hgsubstate'] and changes[1] == [] and
-                     changes[2] == []):
-                    return None
+                subrepo.writestate(self, state)
 
             # Save commit message in case this transaction gets rolled back
             # (e.g. by a pretxncommit hook).  Leave the content alone on