Rev 2913: Make HeadsCache actually work. in http://people.ubuntu.com/~robertc/baz2.0/graph

[Robert Collins]

At http://people.ubuntu.com/~robertc/baz2.0/graph

------------------------------------------------------------
revno: 2913
revision-id: robertc at robertcollins.net-20071018013101-6zbs4utnk16q59fu
parent: robertc at robertcollins.net-20071017225921-l3ypcpn0p9aawmp5
committer: Robert Collins <robertc at robertcollins.net>
branch nick: graph
timestamp: Thu 2007-10-18 11:31:01 +1000
message:
  Make HeadsCache actually work.
modified:
  bzrlib/graph.py                graph_walker.py-20070525030359-y852guab65d4wtn0-1
=== modified file 'bzrlib/graph.py'
--- a/bzrlib/graph.py	2007-10-17 22:59:21 +0000
+++ b/bzrlib/graph.py	2007-10-18 01:31:01 +0000
@@ -386,7 +386,7 @@
         :return: A set containing the heads, which may be mutated without
             affecting future lookups.
         """
-        keys = set(keys)
+        keys = frozenset(keys)
         try:
             return set(self._heads[keys])
         except KeyError: