diff -r 8040a44aab1c -r bbf4f3dfd700 mercurial/revset.py
--- a/mercurial/revset.py	Wed Sep 17 19:52:34 2014 -0700
+++ b/mercurial/revset.py	Wed Sep 17 11:00:09 2014 -0700
@@ -1346,7 +1346,7 @@
     except (TypeError, ValueError):
         # i18n: "rev" is a keyword
         raise error.ParseError(_("rev expects a number"))
-    return subset.filter(lambda r: r == l)
+    return subset & baseset([l])
 
 def matching(repo, subset, x):
     """``matching(revision [, field])``