localrepo: add a cache with stat info for files under .hg/

mercurial/localrepo.py

@@ -111,6 +111,12 b' class localrepository(repo.repository):'
         self._datafilters = {}
         self._transref = self._lockref = self._wlockref = None
 
+        # A cache for various files under .hg/ that tracks file changes,
+        # (used by the filecache decorator)
+        #
+        # Maps a property name to its util.filecacheentry
+        self._filecache = {}
+
     def _applyrequirements(self, requirements):
         self.requirements = requirements
         openerreqs = set(('revlogv1', 'generaldelta'))

mercurial/statichttprepo.py

@@ -125,6 +125,7 b' class statichttprepository(localrepo.loc'
         self.encodepats = None
         self.decodepats = None
         self.capabilities.difference_update(["pushkey"])
+        self._filecache = {}
 
     def url(self):
         return self._url