diff -r a9331f9561dd -r f236a384d23e hgkw/keyword.py
--- a/hgkw/keyword.py	Tue Aug 31 18:18:28 2010 +0100
+++ b/hgkw/keyword.py	Fri Sep 03 15:59:08 2010 +0100
@@ -511,14 +511,14 @@
         self.lines = kwt.shrinklines(self.fname, self.lines)
 
     def kw_diff(orig, repo, node1=None, node2=None, match=None, changes=None,
-                opts=None):
+                opts=None, prefix=''):
         '''Monkeypatch patch.diff to avoid expansion except when
         comparing against working dir.'''
         if node2 is not None:
             kwt.match = util.never
         elif node1 is not None and node1 != repo['.'].node():
             kwt.restrict = True
-        return orig(repo, node1, node2, match, changes, opts)
+        return orig(repo, node1, node2, match, changes, opts, prefix)
 
     def kwweb_skip(orig, web, req, tmpl):
         '''Wraps webcommands.x turning off keyword expansion.'''