[mythtv-commits] Ticket #7837: SIGABRT on Backend when attempting LiveTV playback

[MythTV]

#7837: SIGABRT on Backend when attempting LiveTV playback
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 Reporter:  doneill@…             |       Owner:  ijr    
     Type:  defect                |      Status:  new    
 Priority:  minor                 |   Milestone:  unknown
Component:  MythTV - General      |     Version:  head   
 Severity:  medium                |     Mlocked:  0      
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 MythFrontend svn 23050M (Dec 31st snapshot)
 MythBackend svn 23050M (same codebase)

 My client is a MediaMVP running the Dec 31, 2009 svn snapshot build.

 It is using protocol 8, and my MythBackend is an SVN build from Dec 31,
 2009 also, although a previous version (around a month old) had the same
 result (protocols 56 and 54 respectively).

 I should point out that using MythFrontend of the same release version as
 the MythBackend works.

 My capture hardware is (in this case) a Kworld 120, Hauppauge HVR-1600,
 and Hauppauge HVR-950Q.

 When I select "Live TV" from the menu, mythbackend mysteriously exits when
 running stand-alone or in valgrind.  In GDB I am informed that the process
 received a SIGABRT from HandleRecorderQuery, and in my backtrace the "pbs"
 pointer has a value of 0x0.

 (From following the source (mainserver.cpp), this shouldn't be possible,
 because of a check done around line 335 of that same file.  Still, I added
 another check near the top of the HandleRecorderQuery function to return;
 if pbs is 0x0, which it doesn't, and I don't know why.)

 I can cause this crash reliably simply by selecting LiveTV on my MediaMVP.
 I've cleaned out my old installation, rebuilt/reinstalled MythTV from the
 latest SVN, and the issue persists.

 Interestingly enough, I'm not receiving a segfault from addressing invalid
 memory (pbs->getSocket(), where pbs = 0x0) but rather a cryptic SIGABRT
 from a qlist error.

 Regardless, I'm pretty convinced the SIGABRT comes from the qlist index
 assertion failing.  I have no idea what/how to fix this, though.

 Relevant log files attached.

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Ticket URL: <http://svn.mythtv.org/trac/ticket/7837>
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