diff -r 84ba30e8c790 -r 64c8ae09162e mercurial/cmdutil.py
--- a/mercurial/cmdutil.py	Sun Apr 08 12:38:24 2012 -0500
+++ b/mercurial/cmdutil.py	Sun Apr 08 12:38:26 2012 -0500
@@ -1006,7 +1006,7 @@
         wanted = set(revs)
     copies = []
 
-    if not slowpath:
+    if not slowpath and match.files():
         # We only have to read through the filelog to find wanted revisions
 
         minrev, maxrev = min(revs), max(revs)