diff -r 3949b825f4bf -r faf0414a8b51 libpurple/protocols/irc/parse.c
--- a/libpurple/protocols/irc/parse.c	Tue Aug 20 14:04:56 2013 +0200
+++ b/libpurple/protocols/irc/parse.c	Wed Aug 21 14:59:29 2013 +0200
@@ -384,7 +384,7 @@
 	do {
 		end = strpbrk(cur, "\002\003\007\017\026\037");
 
-		decoded = g_string_append_len(decoded, cur, end ? end - cur : strlen(cur));
+		decoded = g_string_append_len(decoded, cur, (end ? (goffset)(end - cur) : strlen(cur)));
 		cur = end ? end : cur + strlen(cur);
 
 		switch (*cur) {