mercurial/revset.py

--- a/mercurial/revset.py	Fri Jan 23 20:30:49 2015 -0800
+++ b/mercurial/revset.py	Sat Jan 10 12:56:38 2015 +0900
@@ -1545,7 +1545,7 @@
     except (TypeError, ValueError):
         # i18n: "rev" is a keyword
         raise error.ParseError(_("rev expects a number"))
-    if l not in fullreposet(repo):
+    if l not in fullreposet(repo) and l != node.nullrev:
         return baseset()
     return subset & baseset([l])