--- a/mercurial/match.py	Sun Oct 06 19:25:18 2019 -0400
+++ b/mercurial/match.py	Mon Oct 07 00:04:04 2019 -0400
@@ -1617,7 +1617,7 @@
             continue
 
         linesyntax = syntax
-        for s, rels in syntaxes.iteritems():
+        for s, rels in pycompat.iteritems(syntaxes):
             if line.startswith(rels):
                 linesyntax = rels
                 line = line[len(rels) :]