--- a/mercurial/revlog.py	Thu May 03 15:01:33 2018 -0700
+++ b/mercurial/revlog.py	Thu May 03 15:25:16 2018 -0700
@@ -1524,7 +1524,7 @@
                 return True
             if node is None:
                 raise LookupError(node, self.indexfile, _('no node'))
-            return not isrev(prefix)
+            return True
 
         def maybewdir(prefix):
             return all(c == 'f' for c in prefix)