# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@ens-lyon.org>
# Date 1489615809 25200
# Node ID d4645ae6ba1592a2dc6bc2e82036dd4d090b3a49
# Parent  7aac35ada1cbd32b21b64560e3dc77d1a92ffaa6
hgweb: explicitly tests for None in webutil

Changeset d2878bec55bd removed the mutable default value, but did not explicitly
tested for None. Such implicit testing can introduce semantic and performance
issue. We move to an explicit testing for None as recommended by PEP8:

https://www.python.org/dev/peps/pep-0008/#programming-recommendations

diff -r 7aac35ada1cb -r d4645ae6ba15 mercurial/hgweb/webutil.py
--- a/mercurial/hgweb/webutil.py	Wed Mar 15 15:08:45 2017 -0700
+++ b/mercurial/hgweb/webutil.py	Wed Mar 15 15:10:09 2017 -0700
@@ -143,7 +143,9 @@
 
 class _siblings(object):
     def __init__(self, siblings=None, hiderev=None):
-        self.siblings = [s for s in siblings or [] if s.node() != nullid]
+        if siblings is None:
+            siblings = []
+        self.siblings = [s for s in siblings if s.node() != nullid]
         if len(self.siblings) == 1 and self.siblings[0].rev() == hiderev:
             self.siblings = []