=== modified file 'patchsource.py'
--- patchsource.py	2007-08-01 15:10:21 +0000
+++ patchsource.py	2012-11-14 05:33:05 +0000
@@ -42,8 +42,8 @@
 
 class BzrPatchSource(PatchSource):
     def __init__(self, revision=None, file_list=None):
-        from bzrlib.builtins import tree_files
-        self.tree, self.file_list = tree_files(file_list)
+        from bzrlib.workingtree import WorkingTree
+        self.tree, self.file_list = WorkingTree.open_containing_paths(file_list)
         self.base = self.tree.basedir
         self.revision = revision