chan_sip: Destroy variables on a sip_pvt before copying vars from the sip_peer.

(closes issue #19202)
Reported by: wdoekes
Patches: 
      issue19202_destroy_challenged_invite_chanvars.patch uploaded by wdoekes (license 717)




git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@320055 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -10749,7 +10749,9 @@ static enum check_auth_result check_user_full(struct sip_pvt *p, struct sip_requ
 		ast_copy_flags(&p->flags[0], &user->flags[0], SIP_FLAGS_TO_COPY);
 		ast_copy_flags(&p->flags[1], &user->flags[1], SIP_PAGE2_FLAGS_TO_COPY);
 		if (sipmethod == SIP_INVITE) {
-			/* copy channel vars */
+			/* destroy old channel vars and copy new channel vars */
+			ast_variables_destroy(p->chanvars);
+			p->chanvars = NULL;
 			for (v = user->chanvars ; v ; v = v->next) {
 				if ((tmpvar = ast_variable_new(v->name, v->value))) {
 					tmpvar->next = p->chanvars; 
@@ -10909,7 +10911,9 @@ static enum check_auth_result check_user_full(struct sip_pvt *p, struct sip_requ
 				ast_string_field_set(p, authname, peer->name);
 
 				if (sipmethod == SIP_INVITE) {
-					/* copy channel vars */
+					/* destroy old channel vars and copy new channel vars */
+					ast_variables_destroy(p->chanvars);
+					p->chanvars = NULL;
 					for (v = peer->chanvars ; v ; v = v->next) {
 						if ((tmpvar = ast_variable_new(v->name, v->value))) {
 							tmpvar->next = p->chanvars;