[PATCH for-8.0] ui/vnc: fix bad address parsing

[Vladimir Sementsov-Ogievskiy]

IF addrstr == "[" and websocket is true, hostlen becomes 0 and we try
to access addrstr[hostlen-1] which is bad idea.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@yandex-team.ru>
---
 ui/vnc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ui/vnc.c b/ui/vnc.c
index 88f55cbf3c..8830bfe382 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -3765,7 +3765,7 @@ static int vnc_display_get_address(const char *addrstr,
 
         addr->type = SOCKET_ADDRESS_TYPE_INET;
         inet = &addr->u.inet;
-        if (addrstr[0] == '[' && addrstr[hostlen - 1] == ']') {
+        if (hostlen >= 2 && addrstr[0] == '[' && addrstr[hostlen - 1] == ']') {
             inet->host = g_strndup(addrstr + 1, hostlen - 2);
         } else {
             inet->host = g_strndup(addrstr, hostlen);
-- 
2.34.1