[mythtv] mythbackend 29/fixes crashes

[Ken Bass]

One additional item - whenever this crash happens - this is the 'event' 
in the log preceding it (note this always is on the hour or 1/2 hour 
which probably means the live tv rolls to a new program guide entry):

2018-06-12 10:00:00.127690 N [8593/8603] TVRecEvent 
recordinginfo.cpp:695 (ApplyRecordRecGroupChange) - 
ApplyRecordRecGroupChange: LiveTV to LiveTV (2)
2018-06-12 10:00:01.389053 N [8593/13681] HDHRStreamHandler 
recorders/recorderbase.cpp:501 (FinishRecording) - Finished Recording: 
Container: MPEG2-TS Video Codec: h264 (1280x720 A/R: 3 59.9401fps) Audio 
Codec: ac3
2018-06-12 10:00:01.391463 I [8593/13681] HDHRStreamHandler 
tv_rec.cpp:3385 (RingBufferChanged) - TVRec[1]: RingBufferChanged()
2018-06-12 10:00:01.392507 I [8593/13681] HDHRStreamHandler 
tv_rec.cpp:863 (FinishedRecording) - TVRec[1]: 
FinishedRecording(3818_2018-06-12T13:30:40Z) damaged 
recq:<RecordingQuality overall_score="0" key="3818_2018-06-12T13:30:40Z" 
countinuity_error_count="1" packet_count="4325576">
     <Gap start="2018-06-12T13:00:00Z" end="2018-06-12T13:30:40Z" 
duration="1840" />
</RecordingQuality>

2018-06-12 10:00:01.402178 C [8593/8593] CoreContext 
signalhandling.cpp:305 (handleSignal) - Received Segmentation fault: 
Code 128, PID 0, UID 0, Value 0x7f5e78000020


On 06/13/2018 10:21 AM, Ken Bass wrote:
> Another crash since a complete recompile with the latest 29/fixes.
>
> What about this line would cause a crash and what needs to be fixed to 
> protect against it? 80% of the crashes are on this line.
>
> QString str = list->join("[]:[]");
>
> #4  0x00007fdff34f29c4 in MythSocket::WriteStringListReal 
> (this=0x1cc64f0, list=0x7fdef4ff7ad0, ret=0x7fdef4ff75af) at 
> mythsocket.cpp:727
>> 727     QString str = list->join("[]:[]");
>>
>> (gdb) p *list
>> $3 = {<QList<QString>> = {<QListSpecialMethods<QString>> = {<No data 
>> fields>}, {p = {static shared_null = {ref = {atomic = {
>>               _q_value = {<std::__atomic_base<int>> = {_M_i = -1}, 
>> <No data fields>}}}, alloc = 0, begin = 0, end = 0, array = {0x0}},
>>         d = 0x7fdedc048f30}, d = 0x7fdedc048f30}}, <No data fields>}
>>
>> When it happens it is always the hour or 1/2 hour. I am not sure what 
>> happens at time but I am pretty sure it happens while live TV is 
>> playing somewhere. I don't think it I have seen it happen when idle 
>> or just recording things. 
>
> _______________________________________________
> mythtv-dev mailing list
> mythtv-dev at mythtv.org
> http://lists.mythtv.org/mailman/listinfo/mythtv-dev
> http://wiki.mythtv.org/Mailing_List_etiquette
> MythTV Forums: https://forum.mythtv.org