mercurial/exchangev2.py

--- a/mercurial/exchangev2.py	Tue Sep 04 10:42:24 2018 -0700
+++ b/mercurial/exchangev2.py	Thu Aug 30 14:55:34 2018 -0700
@@ -283,6 +283,7 @@
                 b'tree': b'',
                 b'nodes': batch,
                 b'fields': {b'parents', b'revision'},
+                b'haveparents': True,
             }).result()
 
             # Chomp off header object.
@@ -374,7 +375,8 @@
                 fs.append((path, e.callcommand(b'filedata', {
                     b'path': path,
                     b'nodes': sorted(nodes),
-                    b'fields': {b'parents', b'revision'}
+                    b'fields': {b'parents', b'revision'},
+                    b'haveparents': True,
                 })))
 
                 locallinkrevs[path] = {