# HG changeset patch
# User Pulkit Goyal <pulkit@yandex-team.ru>
# Date 1554038830 -10800
# Node ID f0def07fa82fb436e493a1beddfeb351ed9e4822
# Parent  29c22496dd973a568caae2953866b3d24eae3d6f
branchmap: implement __contains__()

We have good occurences of `if branch in branchmap()` in our code. If
__contains__() is not implemented then it will use __iter__() to find whether
the element exists or not which is not good.

I am bit confused that whether I should move existing callers to hasbranch() or
this patch is a good way.

Differential Revision: https://phab.mercurial-scm.org/D6206

diff -r 29c22496dd97 -r f0def07fa82f mercurial/branchmap.py
--- a/mercurial/branchmap.py	Sun Mar 31 16:20:17 2019 +0300
+++ b/mercurial/branchmap.py	Sun Mar 31 16:27:10 2019 +0300
@@ -182,6 +182,9 @@
     def __getitem__(self, key):
         return self._entries[key]
 
+    def __contains__(self, key):
+        return key in self._entries
+
     def iteritems(self):
         return self._entries.iteritems()