diff -r af5c0c933af8 -r 59af0c7d103f mercurial/patch.py
--- a/mercurial/patch.py	Fri Jul 27 14:48:06 2018 -0700
+++ b/mercurial/patch.py	Fri Jul 27 14:48:34 2018 -0700
@@ -2326,7 +2326,7 @@
         relfiltered = True
 
     if not changes:
-        changes = repo.status(ctx1, ctx2, match=match)
+        changes = ctx1.status(ctx2, match=match)
     modified, added, removed = changes[:3]
 
     if not modified and not added and not removed: