# HG changeset patch
# User Patrick Mezard <pmezard@gmail.com>
# Date 1295709340 -3600
# Node ID d0e0d3d43e1439d63564ab4dddfe0daa69ae2d86
# Parent  2ef915184ff297e38e342397433440ea02abdec6
subrepo: compare svn subrepo state to last committed revision

A subversion project revisions are a subset of the repository revisions, you
can ask subversion to update a working directory from one revision to another
without changing anything. Unfortunately, Mercurial will think the
subrepository has changed and will commit it again. To avoid useless commits,
we compare the subrepository state to its actual "parent" revision. To ensure
ascending compatibility with existing subrepositories which might reference
fake revisions, we also keep comparing with the subrepo working directory
revision.

NOTE: not sure if this should go in stable or not.

diff -r 2ef915184ff2 -r d0e0d3d43e14 mercurial/subrepo.py
--- a/mercurial/subrepo.py	Fri Jan 21 14:42:15 2011 -0600
+++ b/mercurial/subrepo.py	Sat Jan 22 16:15:40 2011 +0100
@@ -499,13 +499,23 @@
             raise util.Abort(stderr)
         return stdout
 
-    def _wcrev(self):
+    def _wcrevs(self):
+        # Get the working directory revision as well as the last
+        # commit revision so we can compare the subrepo state with
+        # both. We used to store the working directory one.
         output = self._svncommand(['info', '--xml'])
         doc = xml.dom.minidom.parseString(output)
         entries = doc.getElementsByTagName('entry')
-        if not entries:
-            return '0'
-        return str(entries[0].getAttribute('revision')) or '0'
+        lastrev, rev = '0', '0'
+        if entries:
+            rev = str(entries[0].getAttribute('revision')) or '0'
+            commits = entries[0].getElementsByTagName('commit')
+            if commits:
+                lastrev = str(commits[0].getAttribute('revision')) or '0'
+        return (lastrev, rev)
+
+    def _wcrev(self):
+        return self._wcrevs()[0]
 
     def _wcchanged(self):
         """Return (changes, extchanges) where changes is True
@@ -534,7 +544,7 @@
         return bool(changes), False
 
     def dirty(self):
-        if self._wcrev() == self._state[1] and not self._wcchanged()[0]:
+        if self._state[1] in self._wcrevs() and not self._wcchanged()[0]:
             return False
         return True
 
diff -r 2ef915184ff2 -r d0e0d3d43e14 tests/test-subrepo-svn.t
--- a/tests/test-subrepo-svn.t	Fri Jan 21 14:42:15 2011 -0600
+++ b/tests/test-subrepo-svn.t	Sat Jan 22 16:15:40 2011 +0100
@@ -123,6 +123,25 @@
    source   file://*/svn-repo/src (glob)
    revision 2
 
+add an unrelated revision in svn and update the subrepo to without
+bringing any changes.
+
+  $ svn mkdir --parents "$SVNREPO/unrelated" -m 'create unrelated'
+  
+  Committed revision 4.
+  $ svn up s
+  
+  Fetching external item into 's/externals'
+  External at revision 1.
+  
+  At revision 4.
+  $ hg sum
+  parent: 2:* tip (glob)
+   Message!
+  branch: default
+  commit: (clean)
+  update: (current)
+
   $ echo a > s/a
 
 should be empty despite change to s/a
@@ -139,14 +158,14 @@
   A    externals/other
   Updated external to revision 1.
   
-  Updated to revision 3.
+  Updated to revision 4.
   $ echo xyz >> alpha
   $ svn propset svn:mime-type 'text/xml' alpha
   property 'svn:mime-type' set on 'alpha'
   $ svn ci -m 'amend a from svn'
   Sending        src/alpha
   Transmitting file data .
-  Committed revision 4.
+  Committed revision 5.
   $ cd ../../sub/t
 
 this commit from hg will fail