--- a/mercurial/commands.py	Tue Mar 08 14:55:31 2011 -0600
+++ b/mercurial/commands.py	Tue Mar 08 08:41:39 2011 -0500
@@ -4053,7 +4053,7 @@
     if rev and node:
         raise util.Abort(_("please specify just one revision"))
 
-    if not rev:
+    if rev is None or rev == '':
         rev = node
 
     # if we defined a bookmark, we have to remember the original bookmark name