[asterisk-bugs] [Asterisk 0016057]: Asterisk crashes with "Fixup failed on channel XXX, strange things may happen."

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=16057 
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Reported By:                amorsen
Assigned To:                
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Project:                    Asterisk
Issue ID:                   16057
Category:                   Core/General
Reproducibility:            sometimes
Severity:                   crash
Priority:                   normal
Status:                     acknowledged
Asterisk Version:           1.6.0.16-rc2 
JIRA:                       SWP-303 
Regression:                 No 
Reviewboard Link:            
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2009-10-12 08:23 CDT
Last Modified:              2010-06-29 05:23 CDT
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Summary:                    Asterisk crashes with "Fixup failed on channel XXX,
strange things may happen."
Description: 
[Oct 12 11:26:07] WARNING[1684] channel.c: Fixup failed on channel
Local/1127-0004132c4403-1 at DialLine-3d9b;1<MASQ>, strange things may happen.
[Oct 12 11:26:07] WARNING[1684] channel.c: Hangup failed!  Strange things
may happen!
[Oct 12 11:26:07] WARNING[1684] channel.c: Failed to perform masquerade
[Oct 12 11:26:07] WARNING[1684] channel.c: Channel
'Local/1127-0004132c4403-1 at DialLine-3d9b;1' may not have been hung up
properly

The bug happens several times a day.
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---------------------------------------------------------------------- 
 (0123996) ramonpeek (reporter) - 2010-06-29 05:23
 https://issues.asterisk.org/view.php?id=16057#c123996 
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When this error occurs, it always happens after a SIP device answers a call
that was dialed via multiple LOCAL channels.

So, I've got a theory what might be going wrong;
--- maybe someone might see the light ;-) ---


Scenario:
-----------
- A call is made to an extension that initiates a call via a LOCAL channel
to a new part of the dialplan.
- This part of the dialplan executes numerous dial statements for other
LOCAL channels, resulting in two or more LOCAL channels based on the first
LOCAL channel. (we do this to create special huntgroups)
- From these extra LOCAL channels different SIP devices are called.

My theory:
-----------
When one of the SIP devices answers the LOCAL channels are being bridged
an removed from the channels list. But I think that in some cases the first
LOCAL channel is being removed from the channels list before all other
LOCAL channels that were initiated from this LOCAL channel were removed.
Because our traces indeed show that the first LOCAL channel was indeed
removed before all other LOCAL channels were removed.

To test my theory I used the "/n" dial option on the dial statement for
the first LOCAL channel and since that change this error hasn't occurred
anymore.
However using the "/n" dial option is not really what I want and caused
other problems for me, so we need a real solution instead of this
workaround.

Also I can easily imagine that this problem can also occur on non-LOCAL
channels, just as long as there is a chance that the "mother" channel is
being removed from the channel list before all "child" channels this theory
should stand.

Anyone with better knowledge about the asterisk code have any comment on
this theory? 

Issue History 
Date Modified    Username       Field                    Change               
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2010-06-29 05:23 ramonpeek      Note Added: 0123996                          
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