Fix "duplicate answer" issue (bug #2342)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@3710 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channel.c

@@ -1359,6 +1359,10 @@ struct ast_frame *ast_read(struct ast_channel *chan)
 			ast_log(LOG_WARNING, "Dropping deferred DTMF digits on %s\n", chan->name);
 		f = &null_frame;
 	} else if ((f->frametype == AST_FRAME_CONTROL) && (f->subclass == AST_CONTROL_ANSWER)) {
+		if (chan->_state == AST_STATE_UP) {
+			ast_log(LOG_DEBUG, "Dropping duplicate answer!\n");
+			f = &null_frame;
+		}
 		/* Answer the CDR */
 		ast_setstate(chan, AST_STATE_UP);
 		ast_cdr_answer(chan->cdr);

channels/chan_sip.c

@@ -6580,7 +6580,6 @@ static void handle_response(struct sip_pvt *p, int resp, char *rest, struct sip_
 #ifdef OSP_SUPPORT	
 						time(&p->ospstart);
 #endif
-						ast_setstate(p->owner, AST_STATE_UP);
 						ast_queue_control(p->owner, AST_CONTROL_ANSWER);
 					} else {
 						struct ast_frame af = { AST_FRAME_NULL, };