diff -r b880cc11da5d -r b2601c5977a4 mercurial/hgweb/protocol.py
--- a/mercurial/hgweb/protocol.py	Sun Oct 15 00:05:43 2017 -0400
+++ b/mercurial/hgweb/protocol.py	Sun Oct 15 00:38:33 2017 -0400
@@ -75,10 +75,10 @@
         args.update(cgi.parse_qs(argvalue, keep_blank_values=True))
         return args
     def getfile(self, fp):
-        length = int(self.req.env['CONTENT_LENGTH'])
+        length = int(self.req.env[r'CONTENT_LENGTH'])
         # If httppostargs is used, we need to read Content-Length
         # minus the amount that was consumed by args.
-        length -= int(self.req.env.get('HTTP_X_HGARGS_POST', 0))
+        length -= int(self.req.env.get(r'HTTP_X_HGARGS_POST', 0))
         for s in util.filechunkiter(self.req, limit=length):
             fp.write(s)
     def redirect(self):