Rev 3056: Special case when the candidate_descendant is also the NULL_REVISION in http://bzr.arbash-meinel.com/branches/bzr/0.93-dev/is_ancestor_fix

[John Arbash Meinel]

At http://bzr.arbash-meinel.com/branches/bzr/0.93-dev/is_ancestor_fix

------------------------------------------------------------
revno: 3056
revision-id:john at arbash-meinel.com-20071130152015-7zu3hejdrx5j2reo
parent: john at arbash-meinel.com-20071130145230-njpq31mmf39l2zow
committer: John Arbash Meinel <john at arbash-meinel.com>
branch nick: is_ancestor_fix
timestamp: Fri 2007-11-30 09:20:15 -0600
message:
  Special case when the candidate_descendant is also the NULL_REVISION
modified:
  bzrlib/graph.py                graph_walker.py-20070525030359-y852guab65d4wtn0-1
-------------- next part --------------
=== modified file 'bzrlib/graph.py'
--- a/bzrlib/graph.py	2007-11-30 14:52:30 +0000
+++ b/bzrlib/graph.py	2007-11-30 15:20:15 +0000
@@ -350,6 +350,11 @@
         """
         if revision.is_null(candidate_ancestor):
             return True
+        if revision.is_null(candidate_descendant):
+            # if candidate_descendant is NULL_REVISION, then only
+            # candidate_ancestor == NULL_REVISION is an ancestor, but we've
+            # already handled that case.
+            return False
         return set([candidate_descendant]) == self.heads(
             [candidate_ancestor, candidate_descendant])