app_agent_pool: Made agent alert interruptable by DTMF.

Made agent able to interrupt the alerting beep playback with DTMF.  Any
digit can interrupt if the call does not need to be acknowledged.  Only
the first digit of the acknowledgement can interrupt if the call needs to
be acknowledged.  The agent interrupting the alerting playback builds on
the ASTERISK-24447 patch because it knows what digit interrupted the
playback and needs to be able to pass that digit to the DTMF hook digit
collection code.

ASTERISK-24257 #close
Reported by: Steve Pitts

Review: https://reviewboard.asterisk.org/r/4123/
........

Merged revisions 427508 from http://svn.asterisk.org/svn/asterisk/branches/12
........

Merged revisions 427512 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@427519 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_agent_pool.c

@@ -1733,7 +1733,10 @@ static void agent_alert(struct ast_bridge_channel *bridge_channel, const void *p
 {
 	const char *agent_id = payload;
 	const char *playfile;
-	RAII_VAR(struct agent_pvt *, agent, NULL, ao2_cleanup);
+	const char *dtmf_accept;
+	struct agent_pvt *agent;
+	int digit;
+	char dtmf[2];
 
 	agent = ao2_find(agents, agent_id, OBJ_KEY);
 	if (!agent) {
@@ -1748,30 +1751,56 @@ static void agent_alert(struct ast_bridge_channel *bridge_channel, const void *p
 	ast_bridge_channel_establish_roles(bridge_channel);
 	ast_bridge_unlock(bridge_channel->bridge);
 
-	/* Alert the agent. */
 	agent_lock(agent);
 	playfile = ast_strdupa(agent->cfg->beep_sound);
+
+	/* Determine which DTMF digits interrupt the alerting signal. */
+	if (ast_test_flag(agent, AGENT_FLAG_ACK_CALL)
+		? agent->override_ack_call : agent->cfg->ack_call) {
+		dtmf_accept = ast_test_flag(agent, AGENT_FLAG_DTMF_ACCEPT)
+			? agent->override_dtmf_accept : agent->cfg->dtmf_accept;
+
+		/* Only the first digit of the ack will stop playback. */
+		dtmf[0] = *dtmf_accept;
+		dtmf[1] = '\0';
+		dtmf_accept = dtmf;
+	} else {
+		dtmf_accept = NULL;
+	}
 	agent_unlock(agent);
-	ast_stream_and_wait(bridge_channel->chan, playfile, AST_DIGIT_NONE);
+
+	/* Alert the agent. */
+	digit = ast_stream_and_wait(bridge_channel->chan, playfile,
+		ast_strlen_zero(dtmf_accept) ? AST_DIGIT_ANY : dtmf_accept);
+	ast_stopstream(bridge_channel->chan);
 
 	agent_lock(agent);
 	switch (agent->state) {
 	case AGENT_STATE_CALL_PRESENT:
-		if (ast_test_flag(agent, AGENT_FLAG_ACK_CALL)
-			? agent->override_ack_call : agent->cfg->ack_call) {
+		if (!ast_strlen_zero(dtmf_accept)) {
 			agent->state = AGENT_STATE_CALL_WAIT_ACK;
 			agent->ack_time = ast_tvnow();
+
+			if (0 < digit) {
+				/* Playback was interrupted by a digit. */
+				agent_unlock(agent);
+				ao2_ref(agent, -1);
+				ast_bridge_channel_feature_digit(bridge_channel, digit);
+				return;
+			}
 			break;
 		}
 
 		/* Connect to caller now. */
 		ast_debug(1, "Agent %s: Immediately connecting to call.\n", agent->username);
 		agent_connect_caller(bridge_channel, agent);/* Will unlock agent. */
+		ao2_ref(agent, -1);
 		return;
 	default:
 		break;
 	}
 	agent_unlock(agent);
+	ao2_ref(agent, -1);
 }
 
 static int send_alert_to_agent(struct ast_bridge_channel *bridge_channel, const char *agent_id)