diff -r cf59de802883 -r 7b12a2d2eedc mercurial/patch.py
--- a/mercurial/patch.py	Sat Jun 16 17:56:37 2018 +0900
+++ b/mercurial/patch.py	Sat Jun 16 19:31:07 2018 +0900
@@ -112,7 +112,7 @@
             cur.append(line)
         c = chunk(cur)
 
-        m = pycompat.emailparser().parse(c)
+        m = mail.parse(c)
         if not m.is_multipart():
             yield msgfp(m)
         else:
@@ -230,7 +230,7 @@
 
     data = {}
 
-    msg = pycompat.emailparser().parse(fileobj)
+    msg = mail.parse(fileobj)
 
     subject = msg[r'Subject'] and mail.headdecode(msg[r'Subject'])
     data['user'] = msg[r'From'] and mail.headdecode(msg[r'From'])