localrepo: decorate manifest() with filecache

mercurial/localrepo.py

@@ -184,7 +184,7 b' class localrepository(repo.repository):'
                 c.readpending('00changelog.i.a')
         return c
 
-    @propertycache
+    @filecache('00manifest.i', True)
     def manifest(self):
         return manifest.manifest(self.sopener)