--- a/mercurial/subrepo.py	Tue May 12 13:06:34 2020 -0700
+++ b/mercurial/subrepo.py	Thu May 07 16:54:17 2020 -0400
@@ -617,8 +617,8 @@
                 ui,
                 self._repo,
                 diffopts,
-                node1,
-                node2,
+                self._repo[node1],
+                self._repo[node2],
                 match,
                 prefix=prefix,
                 listsubrepos=True,