[asterisk-dev] Re-invite can destroy ${HANGUPCAUSE}

[Dave Woolley]

I've come across an apparent problem in Asterisk (still present in 1.6.2
SVN) in that the response to a re-invite will update hangupcause in the
channel structure. The ${HANGUPCAUSE} "variable", returned by Dial,
etc., isn't really a variable, but rather a function to read this field,
and can therefore change asynchronously, because re-invites are not
tightly synchronised with the dialplan.

Unfortunately I'm using a significantly patched version and the
re-invite that I'm using is one I added to deal with PABXes that only
honour REFER when they are on hold, and, in fact, I'm looking at
HANGUGCAUSE after the Transfer, not after a Dial.

I do have a patch which stops re-invite responses updating hangupcause.

At the moment, I haven't thought of a problem case that affects the
standard code, although I wonder if enabling early media, or even the
use of Progress() might introduce problem re-invites.

Do I have a sufficient case to raise an issue on the issue tracker?
Also, can anyone think of a simple case that would trigger a re-invite
after a failed Dial application, so that I could demonstrate a bug in
the current code.

As this is a public list, the confidentiality part of the following
doesn't apply.

-- 
David Woolley
BTS Holdings Plc
Tel: +44 (0)20 8401 9000 Fax: +44 (0)20 8401 9100
http://www.bts.co.uk 

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