--- a/hgext/evolve.py	Wed Jun 27 03:37:49 2012 +0200
+++ b/hgext/evolve.py	Wed Jun 27 03:51:54 2012 +0200
@@ -610,6 +610,9 @@
             repo.dirstate.setparents(newid, node.nullid)
             _uncommitdirstate(repo, old, match)
             updatebookmarks(newid)
+            if not repo[newid].files():
+                ui.warn(_("new changeset is empty\n"))
+                ui.status(_('(use "hg kill ." to remove it)\n'))
         finally:
             wlock.release()
     finally: