fix seg in recent change

diff --git a/libs/freetdm/mod_freetdm/mod_freetdm.c b/libs/freetdm/mod_freetdm/mod_freetdm.c
index 1e07db5e318cbf8ad41cdfe8956b3f249f79b8be..9ae717d8cb3af1f10d80fb5e2ea444ae554f74f0 100755 (executable)
--- a/libs/freetdm/mod_freetdm/mod_freetdm.c
+++ b/libs/freetdm/mod_freetdm/mod_freetdm.c
@@ -545,7 +545,7 @@ static switch_status_t channel_on_hangup(switch_core_session_t *session)
        tokencnt = ftdm_channel_get_token_count(tech_pvt->ftdmchan);
        for (t = 0; t < tokencnt; t++) {
                token = ftdm_channel_get_token(tech_pvt->ftdmchan, tokencnt);
-               if (!strcasecmp(uuid, token)) {
+               if (!zstr(token) && !strcasecmp(uuid, token)) {
                        uuid_found = 1;
                        break;
                }