diff -r 91f3ac205816 -r 1093ad1e8903 hgext/rebase.py
--- a/hgext/rebase.py	Fri Jun 01 12:37:18 2012 -0700
+++ b/hgext/rebase.py	Fri Jun 01 12:45:16 2012 -0700
@@ -321,7 +321,7 @@
             # Remove no more useful revisions
             rebased = [rev for rev in state if state[rev] != nullmerge]
             if rebased:
-                if set(repo.changelog.descendants(min(rebased))) - set(state):
+                if set(repo.changelog.descendants([min(rebased)])) - set(state):
                     ui.warn(_("warning: new changesets detected "
                               "on source branch, not stripping\n"))
                 else:
@@ -575,7 +575,7 @@
 
     descendants = set()
     if dstates:
-        descendants = set(repo.changelog.descendants(*dstates))
+        descendants = set(repo.changelog.descendants(dstates))
     if descendants - set(dstates):
         repo.ui.warn(_("warning: new changesets detected on target branch, "
                        "can't abort\n"))