[PATCH 2 of 4 marmoute-reviewed] localrepo: add a way to get the current wlock if it's held

[Siddharth Agarwal]

# HG changeset patch
# User Siddharth Agarwal <sid0 at fb.com>
# Date 1444080457 25200
#      Mon Oct 05 14:27:37 2015 -0700
# Node ID 6ed71ec8f372f273089dcddad5984d368c794f26
# Parent  c408266451c7b989b05f089cfa3c7b103b1c8b06
localrepo: add a way to get the current wlock if it's held

This will be useful to pass around a reference to the lock to some functions
we're going to add to scmutil. We don't want those functions to live in
localrepo to avoid bloat.

diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -1309,6 +1309,10 @@ class localrepository(object):
             return None
         return l
 
+    def currentwlock(self):
+        """Returns the wlock if it's held, or None if it's not."""
+        return self._currentlock(self._wlockref)
+
     def _filecommit(self, fctx, manifest1, manifest2, linkrev, tr, changelist):
         """
         commit an individual file as part of a larger transaction