[asterisk-bugs] [Asterisk 0010834]: Empty vars in AEL2 switches lead to dropped calls

[noreply at bugs.digium.com]

A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=10834 
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Reported By:                adiemus
Assigned To:                murf
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Project:                    Asterisk
Issue ID:                   10834
Category:                   PBX/pbx_ael
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     assigned
Asterisk Version:            1.4.10  
SVN Branch (only for SVN checkouts, not tarball releases): N/A  
SVN Revision (number only!):  
Disclaimer on File?:        N/A 
Request Review:              
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Date Submitted:             09-27-2007 17:59 CDT
Last Modified:              10-02-2007 11:20 CDT
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Summary:                    Empty vars in AEL2 switches lead to dropped calls
Description: 
Occasionally my telco doesn't signal CID data properly, leaving me empty
vars for CALLERID(number) and CALLERID(name).  In my dialplan, I have the
following structure:

switch(${CALLERID(number)}) {
    case 1234567890:
       NoOp(Call from 1234567890);
       break;
    default:
       NoOp(No special processing);
}

In the case of a blank CALLERID(number) I'd expect the default path to
run.  However, this AEL gets translated to:

exten => s,16,Goto(sw-12-${CALLERID(number)}|10)
exten => s,17,NoOp(Finish switch-pstn-inbound-12)
exten => _sw-12-.,10,NoOp(No special processing);
exten => _sw-12-.,11,Goto(s|17)
exten => sw-12-1234567890,10,NoOp(Call from 1234567890)
exten => sw-12-1234567890,11,Goto(s|17)

So when asterisk processes it, I end up with:

    -- Executing [s at pstn-inbound:12] Goto("Zap/4-1", "sw-12-|10") in new
stack
    -- Goto (pstn-inbound,sw-12-,10)
[Sep 27 17:58:13] WARNING[32414]: pbx.c:2450 __ast_pbx_run: Channel
'Zap/4-1' sent into invalid extension 'sw-12-' in context 'pstn-inbound',
but no invalid handler
    -- Hungup 'Zap/4-1'

Not quite sure where the "bug" is here since obviously "sw-12-" won't be
matched by "_sw-12-."  Maybe this is the desired behavior and I'm wrong.

For now I'm just checking if CALLERID(number) is empty first, and
populating it with "0000000000" before the switch() which works around the
problem.

  -Chris

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---------------------------------------------------------------------- 
 murf - 10-02-07 11:20  
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Well, my first reaction was to modify the code so, for switch cases, it
puts a '1' (or any other equally suited character) in front of every case
(except the default), and a '1' at the front of the label in the Goto. This
solved the problem, and I tested it and it works fine for the empty case,
but it's not transparent. The 1 will show up in ${EXTEN} and that's not
good.

So, the only other thing I can think of, is to make a special 'empty'
case, and have that jump to the default case.That would be slightly more
transparent... I think.... 

Issue History 
Date Modified   Username       Field                    Change               
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10-02-07 11:20  murf           Note Added: 0071327                          
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