[PATCH 1 of 6] mergestate: consistently set variables to None

[Gregory Szorc]

# HG changeset patch
# User Gregory Szorc <gregory.szorc at gmail.com>
# Date 1399592908 25200
#      Thu May 08 16:48:28 2014 -0700
# Node ID a3f7aa832261e32c5fc3f8b88285034a8329fc38
# Parent  62a2749895e4151f766a4243fa870b1ddd7386d0
mergestate: consistently set variables to None

Some code branches and exceptional circumstances such as empty
mergestate files could result in mergestate._local and
mergestate._other not being defined or reset to None. These variables
are now correctly set to None when they should be.

diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -57,8 +57,11 @@ class mergestate(object):
         self._state = {}
         if node:
             self._local = node
             self._other = other
+        else:
+            self._local = None
+            self._other = None
         shutil.rmtree(self._repo.join("merge"), True)
         self._dirty = False
 
     def _read(self):
@@ -67,8 +70,10 @@ class mergestate(object):
         This function process "record" entry produced by the de-serialization
         of on disk file.
         """
         self._state = {}
+        self._local = None
+        self._other = None
         records = self._readrecords()
         for rtype, record in records:
             if rtype == 'L':
                 self._local = bin(record)