Answer with multiple codecs if the underlying pjproject supports it.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@395938 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_pjsip_session.c

@@ -947,6 +947,9 @@ int ast_sip_session_create_invite(struct ast_sip_session *session, pjsip_tx_data
 
 	pjsip_inv_set_local_sdp(session->inv_session, offer);
 	pjmedia_sdp_neg_set_prefer_remote_codec_order(session->inv_session->neg, PJ_FALSE);
+#ifdef PJMEDIA_SDP_NEG_ANSWER_MULTIPLE_CODECS
+	pjmedia_sdp_neg_set_answer_multiple_codecs(session->inv_session->neg, PJ_TRUE);
+#endif
 	if (pjsip_inv_invite(session->inv_session, tdata) != PJ_SUCCESS) {
 		return -1;
 	}
@@ -1459,6 +1462,9 @@ static int new_invite(void *data)
 	} else {
 		pjsip_inv_set_local_sdp(invite->session->inv_session, local);
 		pjmedia_sdp_neg_set_prefer_remote_codec_order(invite->session->inv_session->neg, PJ_FALSE);
+#ifdef PJMEDIA_SDP_NEG_ANSWER_MULTIPLE_CODECS
+		pjmedia_sdp_neg_set_answer_multiple_codecs(invite->session->inv_session->neg, PJ_TRUE);
+#endif
 	}
 
 	pjsip_timer_setting_default(&timer);