diff -r 492cd4bbca08 -r 3d0f8918351b mercurial/obsutil.py
--- a/mercurial/obsutil.py	Tue Aug 22 17:16:13 2017 -0400
+++ b/mercurial/obsutil.py	Mon Jul 03 15:33:27 2017 +0200
@@ -590,3 +590,14 @@
         values.append({'successors': sset, 'markers': sset.markers})
 
     return values
+
+def successorsetverb(successorset):
+    """ Return the verb summarizing the successorset
+    """
+    if not successorset:
+        verb = 'pruned'
+    elif len(successorset) == 1:
+        verb = 'rewritten'
+    else:
+        verb = 'split'
+    return verb