=== modified file 'bzrlib/status.py'
--- bzrlib/status.py    2008-06-03 17:51:14 +0000
+++ bzrlib/status.py    2008-07-22 16:44:07 +0000
@@ -161,6 +161,10 @@
     """
     # MergeSorter requires that all nodes be present in the graph, so get rid
     # of any references pointing outside of this graph.
+    if not revision_ids:
+        # There don't seem to be any new revisions introduced by this entry,
+        # shortcut it
+        return iter([tip_revision])
     parent_graph = {}
     for revision_id in revision_ids:
         if revision_id not in parent_map: # ghost