From 8a28bfa3d1de71437fb1eca7b65b506414b18b76 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C5=99emysl=20Janouch?= <p.janouch@gmail.com>
Date: Thu, 11 Jun 2015 21:00:00 +0200
Subject: [PATCH] IRC: properly unescape message tags

---
 liberty-proto.c | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/liberty-proto.c b/liberty-proto.c
index f4934da..c2ea64c 100644
--- a/liberty-proto.c
+++ b/liberty-proto.c
@@ -32,6 +32,35 @@ struct irc_message
 	struct str_vector params;           ///< Command parameters
 };
 
+static char *
+irc_unescape_message_tag (const char *value)
+{
+	struct str s;
+	str_init (&s);
+
+	bool escape = false;
+	for (const char *p = value; *p; p++)
+	{
+		if (escape)
+		{
+			switch (*p)
+			{
+			case ':': str_append_c (&s, ';');  break;
+			case 's': str_append_c (&s, ' ');  break;
+			case 'r': str_append_c (&s, '\r'); break;
+			case 'n': str_append_c (&s, '\n'); break;
+			default:  str_append_c (&s, *p);
+			}
+			escape = false;
+		}
+		else if (*p == '\\')
+			escape = true;
+		else
+			str_append_c (&s, *p);
+	}
+	return str_steal (&s);
+}
+
 static void
 irc_parse_message_tags (const char *tags, struct str_map *out)
 {
@@ -45,7 +74,7 @@ irc_parse_message_tags (const char *tags, struct str_map *out)
 		if (equal_sign)
 		{
 			*equal_sign = '\0';
-			str_map_set (out, key, xstrdup (equal_sign + 1));
+			str_map_set (out, key, irc_unescape_message_tag (equal_sign + 1));
 		}
 		else
 			str_map_set (out, key, xstrdup (""));