diff -r a98a90023261 -r 8f29a08e7bbc mercurial/templatekw.py
--- a/mercurial/templatekw.py	Fri Dec 10 16:10:14 2010 +0100
+++ b/mercurial/templatekw.py	Tue Dec 07 15:50:28 2010 +0100
@@ -162,9 +162,8 @@
     return ctx.description().strip()
 
 def showdiffstat(repo, ctx, templ, **args):
-    diff = patch.diff(repo, ctx.parents()[0].node(), ctx.node())
     files, adds, removes = 0, 0, 0
-    for i in patch.diffstatdata(util.iterlines(diff)):
+    for i in patch.diffstatdata(util.iterlines(ctx.diff())):
         files += 1
         adds += i[1]
         removes += i[2]