[PATCH 4 of 4] localrepo: make _refreshfilecachestats unfiltered method to refresh correctly

[FUJIWARA Katsunori]

# HG changeset patch
# User FUJIWARA Katsunori <foozy at lares.dti.ne.jp>
# Date 1472840250 -32400
#      Sat Sep 03 03:17:30 2016 +0900
# Node ID b4264bfd8cbc814cab2c87f4752a8b05f84f6f77
# Parent  33e29b5ebe885cdeeef433861e2d165b882d48d1
localrepo: make _refreshfilecachestats unfiltered method to refresh correctly

Before this patch, if transaction is started via "filtered repo"
object, _refreshfilecachestats() at closing transaction doesn't
refresh file stat of any @filecache properties correctly, because:

  - _refreshfilecachestats() omits refreshing file stat of a
    @filecache property, if it doesn't appear in self.__dict__

  - if transaction is started via "filtered repo",
    _refreshfilecachestats() is applied on "filtered repo"

    because repo.transaction() adds "self._refreshfilecachestats" to
    post close procedures. repo.transaction() isn't unfiltered method,
    and "self" in it means "filtered repo" in this case.

    Transactions started by explicit repo.transaction() easily causes
    this situation.

  - _refreshfilecachestats() applied on "filtered repo" omits whole
    refreshing

    because @filecache properties are stored into "unfiltered repo",
    and appear only in self.__dict__ of "unfiltered repo".

This incorrect refreshing causes unnecessary reloading from files.

To refresh file stat of @filecache properties at closing transaction
correctly, this patch makes _refreshfilecachestats() unfiltered
method.

This patch chooses making _refreshfilecachestats() unfiltered method
instead of making transaction() unfiltered method, to reduce
unexpected side effect.

diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -1276,6 +1276,7 @@ class localrepository(object):
         self.invalidate()
         self.invalidatedirstate()
 
+    @unfilteredmethod
     def _refreshfilecachestats(self, tr):
         """Reload stats of cached files so that they are flagged as valid"""
         for k, ce in self._filecache.items():