diff -r 6f14253416bd -r 62d7287fe6b0 hgext/rebase.py
--- a/hgext/rebase.py	Wed Apr 15 10:33:58 2009 -0500
+++ b/hgext/rebase.py	Sat Apr 25 22:25:49 2009 +0200
@@ -128,8 +128,7 @@
 
         if not keepf:
             # Remove no more useful revisions
-            if (set(repo.changelog.descendants(min(state)))
-                                                    - set(state.keys())):
+            if set(repo.changelog.descendants(min(state))) - set(state):
                 ui.warn(_("warning: new changesets detected on source branch, "
                                                         "not stripping\n"))
             else: