hgext/rebase.py

--- a/hgext/rebase.py	Thu Oct 15 01:50:31 2015 +0100
+++ b/hgext/rebase.py	Thu Oct 15 01:51:53 2015 +0100
@@ -287,9 +287,11 @@
             cmdutil.checkunfinished(repo)
             cmdutil.bailifchanged(repo)
 
-            if not destf:
-                destf = '_rebasedefaultdest()'
-            dest = scmutil.revsingle(repo, destf)
+            if destf:
+                dest = scmutil.revsingle(repo, destf)
+            else:
+                dest = repo[_destrebase(repo)]
+                destf = str(dest)
 
             if revf:
                 rebaseset = scmutil.revrange(repo, revf)