[asterisk-bugs] [Asterisk 0010834]: [patch]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:                     feedback
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:              10-03-2007 03:59 CDT
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Summary:                    [patch]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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---------------------------------------------------------------------- 
 dimas - 10-03-07 03:59  
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My first thougt was that this approach will break cases where user
explicitly handles null values with 
case "":

but then I discovered there is no way to specify case with empty string
because empty quotes are just literally copied to label :) Hovewer, your
special null branch to me looks like less transparent then your original
idea of adding extra character to labesl. Amd of empty-string cases will
ever be supported, your patch will make them non-working anyway.

Isn't it possible to just add another dash to label names so labels will
look like sw-15--1234567 where the default one will be _sw-15-. and GoTo
will be going to sw-%d--%s ? I'm not quite sure how this extra dash shows
up in ${EXTEN} and if it does, why is it so bad. 

Issue History 
Date Modified   Username       Field                    Change               
====================================================================== 
10-03-07 03:59  dimas          Note Added: 0071384                          
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