diff -r 983cda0e110c -r e1dae2ef5588 mercurial/changelog.py
--- a/mercurial/changelog.py	Tue Nov 05 14:23:32 2019 -0800
+++ b/mercurial/changelog.py	Tue Nov 05 14:31:50 2019 -0800
@@ -404,12 +404,6 @@
         self.filteredrevs = frozenset()
         self._copiesstorage = opener.options.get(b'copies-storage')
 
-    def parentrevs(self, rev):
-        """filtered version of revlog.parentrevs"""
-        if rev in self.filteredrevs:
-            raise error.FilteredIndexError(rev)
-        return super(changelog, self).parentrevs(rev)
-
     def flags(self, rev):
         """filtered version of revlog.flags"""
         if rev in self.filteredrevs: