Failure in media negotiation when SDP contains two audio media lines (thanks Arie Velthoen)

[bennylp]

PJSUA-LIB will fail to start audio when the SDP in incoming INVITE contains two audio media lines, for example:

v=0
o=- 1197975037 1197975037 IN IP4 192.168.9.74
s=-
c=IN IP4 192.168.9.74
t=0 0
m=audio 49200 RTP/SAVP 8 0 9 18 96
a=sendrecv
a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:tMuyik1Aiiq9p4DQVHhAASSWDEP7K7wo0cICOn39
a=rtpmap:8 PCMA/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:9 G722/8000
a=rtpmap:18 G729/8000
a=rtpmap:96 telephone-event/8000
m=audio 49200 RTP/AVP 8 0 9 18 96
a=rtpmap:8 PCMA/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:9 G722/8000
a=rtpmap:18 G729/8000
a=rtpmap:96 telephone-event/8000

In this case, PJSUA-LIB treats the first m= line as the audio media, but since the transport is not supported, the audio will not be active.

Thanks Arie Velthoen for pointing this out.

[bennylp]

Fixed in r1639