--- a/mercurial/branchmap.py	Fri Aug 12 11:36:42 2016 +0900
+++ b/mercurial/branchmap.py	Wed May 03 11:16:55 2017 +0900
@@ -67,8 +67,6 @@
             partial.setdefault(label, []).append(node)
             if state == 'c':
                 partial._closednodes.add(node)
-    except KeyboardInterrupt:
-        raise
     except Exception as inst:
         if repo.ui.debugflag:
             msg = 'invalid branchheads cache'