bridge_native_rtp/bridge_channel: Fix direct media issues due to frame hook

This patch fixes issues with direct media bridges that occur after a blind
transfer. These issues were caught by the (currently failing)
pjsip/transfers/blind_transfer/caller_direct_media test.

The test currently fails primarily for two reasons:
(1) When Bob and Charlie (the transfer target and the transfer destination)
    enter a bridge together, the framehook remains on the transfer target
    channel until both channels are in the bridge. As it consumes voice frames,
    the initial bridge type is a simple bridge. The framehook is removed when
    both channels are in the bridge; however, this does not currently cause the
    bridging framework to re-evaluate the bridge. This patch adds a
    AST_SOFTHANGUP_UNBRIDGE poke to the transfer target channel when a
    framehook is removed so the bridge can re-evaluate itself.

(2) When a channel leaves a native RTP bridge, it may be leaving due to being
    hung up. Sending a re-INVITE to a channel that is about to be hung up is
    not nice - in fact, there's a good chance we'll send the BYE request before
    the channel has had a chance to send back a 200 OK. To be somewhat nicer,
    this patch adds a function to channel.h that allows the bridging framework
    to query for exactly why a channel is leaving a bridge via the channel's
    soft hangup flags. This allows it to only send the re-INVITE if there's a
    chance the channel will survive the native bridging experience.

Review: https://reviewboard.asterisk.org/r/3535/
........

Merged revisions 414122 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@414123 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 7 insertions, 4 deletions

diff --git a/bridges/bridge_native_rtp.c b/bridges/bridge_native_rtp.c
index 7e48ab92f..aa5299c24 100644
--- a/bridges/bridge_native_rtp.c
+++ b/bridges/bridge_native_rtp.c
@@ -230,8 +230,10 @@ static void native_rtp_bridge_stop(struct ast_bridge *bridge, struct ast_channel
 		break;
 	case AST_RTP_GLUE_RESULT_REMOTE:
 		if (!target) {
-			glue0->update_peer(c0->chan, NULL, NULL, NULL, NULL, 0);
-			if (glue1) {
+			if (ast_channel_is_leaving_bridge(c0->chan)) {
+				glue0->update_peer(c0->chan, NULL, NULL, NULL, NULL, 0);
+			}
+			if (glue1 && ast_channel_is_leaving_bridge(c1->chan)) {
 				glue1->update_peer(c1->chan, NULL, NULL, NULL, NULL, 0);
 			}
 		} else {
@@ -485,8 +487,9 @@ static void native_rtp_bridge_leave(struct ast_bridge *bridge, struct ast_bridge
 	}
 
 	/* Direct RTP may have occurred, tear it down */
-	glue->update_peer(bridge_channel->chan, NULL, NULL, NULL, NULL, 0);
-
+	if (ast_channel_is_leaving_bridge(bridge_channel->chan)) {
+		glue->update_peer(bridge_channel->chan, NULL, NULL, NULL, NULL, 0);
+	}
 	native_rtp_bridge_stop(bridge, NULL);
 }