localrepo: introduce a `_refreshchangelog` method

See next changeset for usage and documentation for details.

mercurial/bundlerepo.py

@@ -365,6 +365,11 b' class bundlerepository(object):'
         self.manstart = self._cgunpacker.tell()
         return c
 
+    def _refreshchangelog(self):
+        # changelog for bundle repo are not filecache, this method is not
+        # applicable.
+        pass
+
     @localrepo.unfilteredpropertycache
     def manifestlog(self):
         self._cgunpacker.seek(self.manstart)

mercurial/localrepo.py

@@ -1224,6 +1224,11 b' class localrepository(object):'
     def _bookmarks(self):
         return bookmarks.bmstore(self)
 
+    def _refreshchangelog(self):
+        """make sure the in memory changelog match the on-disk one"""
+        if ('changelog' in vars(self) and self.currenttransaction() is None):
+            del self.changelog
+
     @property
     def _activebookmark(self):
         return self._bookmarks.active