mercurial/mail.py

--- a/mercurial/mail.py	Mon Oct 07 11:52:58 2019 -0400
+++ b/mercurial/mail.py	Wed Oct 02 07:35:22 2019 +0900
@@ -168,9 +168,10 @@
 def _sendmail(ui, sender, recipients, msg):
     '''send mail using sendmail.'''
     program = ui.config(b'email', b'method')
-    stremail = lambda x: (
-        procutil.quote(stringutil.email(encoding.strtolocal(x)))
-    )
+
+    def stremail(x):
+        return procutil.shellquote(stringutil.email(encoding.strtolocal(x)))
+
     cmdline = b'%s -f %s %s' % (
         program,
         stremail(sender),