From a86e6f8c7c9a3aebb894dc047545c8902e850e71 Mon Sep 17 00:00:00 2001
From: Oswald Buddenhagen <ossi@users.sf.net>
Date: Wed, 14 Apr 2021 16:52:31 +0200
Subject: [PATCH] don't crash on malformed CAPABILITY responses

amends 95a83c822.

this problem was found by Lukas Braun <koomi@moshbit.net> using a
fuzzer.
---
 src/drv_imap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/drv_imap.c b/src/drv_imap.c
index d4fcc1f..edae95c 100644
--- a/src/drv_imap.c
+++ b/src/drv_imap.c
@@ -1273,7 +1273,7 @@ parse_response_code( imap_store_t *ctx, imap_cmd_t *cmd, char *s )
 			return RESP_CANCEL;
 		}
 	} else if (!strcmp( "CAPABILITY", arg )) {
-		if (!(p = strchr( s, ']' ))) {
+		if (!s || !(p = strchr( s, ']' ))) {
 			error( "IMAP error: malformed CAPABILITY status\n" );
 			return RESP_CANCEL;
 		}