[PATCH] subrepo: don't commit in subrepo if it's clean

[Kevin Bullock]

# HG changeset patch
# User Kevin Bullock <kbullock at ringworld.org>
# Date 1311101033 18000
# Branch stable
# Node ID e0eecff0ced05767a72ff36418396147aaf1ee73
# Parent  c0ccd70df52cbc361aef372514d61a2fd91f057e
subrepo: don't commit in subrepo if it's clean

If a subrepo has changed relative to the outer repo's substate, but the
subrepo itself is clean, we don't need to commit in the subrepo.

diff --git a/mercurial/subrepo.py b/mercurial/subrepo.py
--- a/mercurial/subrepo.py
+++ b/mercurial/subrepo.py
@@ -421,6 +421,10 @@
 
     def commit(self, text, user, date):
         self._repo.ui.debug("committing subrepo %s\n" % subrelpath(self))
+        # don't bother committing in the subrepo if it's only been
+        # updated
+        if not self.dirty(True):
+            return self._repo['.'].hex()
         n = self._repo.commit(text, user, date)
         if not n:
             return self._repo['.'].hex() # different version checked out
diff --git a/tests/test-mq-subrepo.t b/tests/test-mq-subrepo.t
--- a/tests/test-mq-subrepo.t
+++ b/tests/test-mq-subrepo.t
@@ -348,3 +348,14 @@
   % debugsub should be empty
 
   $ cd ..
+
+
+correctly handle subrepos with patch queues
+  $ mkrepo repo-subrepo-with-queue
+  $ mksubrepo sub
+  adding a
+  $ hg -R sub qnew sub0.diff
+  $ echo sub = sub >> .hgsub
+  $ hg add .hgsub
+  $ hg qnew 0.diff
+  committing subrepository sub