From 8abe7e6cda7bc9f8daa4e9cf6ef7e51b356902d5 Mon Sep 17 00:00:00 2001
From: Eric Wong <e@80x24.org>
Date: Wed, 20 Jul 2022 09:24:10 +0000
Subject: [PATCH] pop3: implement IN-USE from RESP-CODES (RFC 2449)

This may help clients communicate to users if they're
making parallel connections or if we have server bugs.
---
 lib/PublicInbox/POP3.pm | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/PublicInbox/POP3.pm b/lib/PublicInbox/POP3.pm
index 86123563..51c2b71a 100644
--- a/lib/PublicInbox/POP3.pm
+++ b/lib/PublicInbox/POP3.pm
@@ -176,7 +176,7 @@ sub _login_ok ($) {
 		$self->{uid_max} = $self->{ibx}->over(1)->max;
 		\"+OK logged in\r\n";
 	} else {
-		\"-ERR unable to lock maildrop\r\n";
+		\"-ERR [IN-USE] unable to lock maildrop\r\n";
 	}
 }
 
@@ -350,6 +350,7 @@ USER\r
 PIPELINING\r
 UIDL\r
 EXPIRE 0\r
+RESP-CODES\r
 .\r
 EOM
 }
-- 
2.44.0