Only drop audio if we receive it without a progress indication. We allow other frames through such as DTMF because they may be needed to complete the call.

(closes issue #12440)
Reported by: aragon


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@114322 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -4386,7 +4386,7 @@ static struct ast_frame *sip_read(struct ast_channel *ast)
 	}
 
 	/* Only allow audio through if they sent progress with SDP, or if the channel is actually answered */
-	if (p->invitestate != INV_EARLY_MEDIA && ast->_state != AST_STATE_UP) {
+	if (fr->frametype == AST_FRAME_VOICE && p->invitestate != INV_EARLY_MEDIA && ast->_state != AST_STATE_UP) {
 		fr = &ast_null_frame;
 	}