MT#55283 codec_last_dtmf_event: return ts of dtmf_state if handler queue is empty

this function is used to determine if a pause is needed on a new
injected DTMF's start ts to ensure a gap between the events. However,
if an inject request comes in after the end of the previous event
but before it would have been offset due to pause, no pause is added

This change returns the ts value from dtmf_state if the queue is
empty as that will always be the ts of the last DTMF transmitted

Change-Id: I4f3cf5115d1a8e26c0ca1bc9570c46e29391e0d0
(cherry picked from commit bdb1022677)

daemon/codec.c

@@ -2666,7 +2666,7 @@ void codec_add_dtmf_event(struct codec_ssrc_handler *ch, int code, int level, ui
 uint64_t codec_last_dtmf_event(struct codec_ssrc_handler *ch) {
 	struct dtmf_event *ev = t_queue_peek_tail(&ch->dtmf_events);
 	if (!ev)
-		return 0;
+		ev = &ch->dtmf_state;
 	return ev->ts;
 }
 

t/auto-daemon-tests.pl

@@ -1787,25 +1787,27 @@ $resp = rtpe_req('play DTMF', 'inject DTMF towards B over received DTMF',
        { 'from-tag' => ft(), code => '1', volume => 12, duration => 100 });
 
 snd($sock_a, $port_b, rtp(101, 1022, 6040, 0x1234, "\x03\x26\x01\x40"));
-rcv($sock_b, $port_a, rtpm(101 | 0x80, 1024, 6200, 0x1234, "\x01\x0c\x00\xa0"));
+rcv_no($sock_b);
 snd($sock_a, $port_b, rtp(101, 1023, 6040, 0x1234, "\x03\x26\x01\xe0"));
-rcv($sock_b, $port_a, rtpm(101, 1025, 6200, 0x1234, "\x01\x0c\x01\x40"));
+rcv($sock_b, $port_a, rtpm(101 | 0x80, 1025, 6360, 0x1234, "\x01\x0c\x00\xa0"));
 snd($sock_a, $port_b, rtp(101, 1024, 6040, 0x1234, "\x03\x26\x02\x80"));
-rcv($sock_b, $port_a, rtpm(101, 1026, 6200, 0x1234, "\x01\x0c\x01\xe0"));
+rcv($sock_b, $port_a, rtpm(101, 1026, 6360, 0x1234, "\x01\x0c\x01\x40"));
 snd($sock_a, $port_b, rtp(101, 1025, 6040, 0x1234, "\x03\x26\x03\x20"));
-rcv($sock_b, $port_a, rtpm(101, 1027, 6200, 0x1234, "\x01\x0c\x02\x80"));
+rcv($sock_b, $port_a, rtpm(101, 1027, 6360, 0x1234, "\x01\x0c\x01\xe0"));
 # send end event
 snd($sock_a, $port_b, rtp(101, 1026, 6040, 0x1234, "\x03\xa6\x03\xc0"));
-rcv($sock_b, $port_a, rtpm(101, 1028, 6200, 0x1234, "\x01\x8c\x03\x20"));
-rcv($sock_b, $port_a, rtpm(101, 1029, 6200, 0x1234, "\x01\x8c\x03\x20"));
-rcv($sock_b, $port_a, rtpm(101, 1030, 6200, 0x1234, "\x01\x8c\x03\x20"));
 snd($sock_a, $port_b, rtp(101, 1027, 6040, 0x1234, "\x03\xa6\x03\xc0"));
-rcv_no($sock_b);
 snd($sock_a, $port_b, rtp(101, 1028, 6040, 0x1234, "\x03\xa6\x03\xc0"));
+rcv($sock_b, $port_a, rtpm(101, 1028, 6360, 0x1234, "\x01\x0c\x02\x80"));
 rcv_no($sock_b);
 # send audio, receive end event
 snd($sock_a, $port_b, rtp(8, 1029, 7000, 0x1234, "\x00" x 160));
-rcv($sock_b, $port_a, rtpm(8, 1033, 7000, 0x1234, "\x00" x 160));
+rcv($sock_b, $port_a, rtpm(101, 1029, 6360, 0x1234, "\x01\x8c\x03\x20"));
+rcv($sock_b, $port_a, rtpm(101, 1030, 6360, 0x1234, "\x01\x8c\x03\x20"));
+rcv($sock_b, $port_a, rtpm(101, 1031, 6360, 0x1234, "\x01\x8c\x03\x20"));
+
+snd($sock_a, $port_b, rtp(8, 1030, 7160, 0x1234, "\x00" x 160));
+rcv($sock_b, $port_a, rtpm(8, 1032, 7160, 0x1234, "\x00" x 160));