Handle a case where a call can be bridged to a channel that is still ringing.

The issue that was reported was about a case where a RINGING channel got 
redirected to an extension to pick up a call from parking.  Once the parked 
call got taken out of parking, it heard silence until the other side answered.  
Ideally, the caller that was parked would get a ringing indication.  This patch
fixes this case so that the caller receives ringback once it comes out of 
parking until the other side answers.

The fixes are:

 - Make sure we remember that a channel was an outgoing channel when doing 
   a masquerade.  This prevents an erroneous ast_answer() call on the channel,
   which causes a bogus 200 OK to be sent in the case of SIP.

 - Add some additional comments to explain related parts of code.

 - Update the handling of the ast_channel visible_indication field.  Storing 
   values that are not stateful is pointless.  Control frames that are events 
   or commands should be ignored.

 - When a bridge first starts, check to see if the peer channel needs to be 
   given ringing indication because the calling side is still ringing.

 - Rework ast_indicate_data() a bit for the sake of readability.

(closes issue #13747)
Reported by: davidw
Tested by: russell
Review: http://reviewboard.digium.com/r/90/


git-svn-id: http://svn.digium.com/svn/asterisk/branches/1.4@164201 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 9 insertions, 1 deletions

diff --git a/res/res_features.c b/res/res_features.c
index be9fab630..8e6799298 100644
--- a/res/res_features.c
+++ b/res/res_features.c
@@ -1474,8 +1474,16 @@ int ast_bridge_call(struct ast_channel *chan,struct ast_channel *peer,struct ast
 	if (chan && peer) {
 		pbx_builtin_setvar_helper(chan, "BRIDGEPEER", peer->name);
 		pbx_builtin_setvar_helper(peer, "BRIDGEPEER", chan->name);
-	} else if (chan)
+	} else if (chan) {
 		pbx_builtin_setvar_helper(chan, "BLINDTRANSFER", NULL);
+	}
+
+	/* This is an interesting case.  One example is if a ringing channel gets redirected to
+	 * an extension that picks up a parked call.  This will make sure that the call taken
+	 * out of parking gets told that the channel it just got bridged to is still ringing. */
+	if (chan->_state == AST_STATE_RINGING && peer->visible_indication != AST_CONTROL_RINGING) {
+		ast_indicate(peer, AST_CONTROL_RINGING);
+	}
 
 	if (monitor_ok) {
 		const char *monitor_exec;