[CRASH] ISO image playback crashes frontend

[finlay@…]

Trying to play a dvd iso image from a storage group crashed the frontend. I'll attach the mythfrontend.log file and a crash dump

[John Finlay <finlay@…>]

mythfrontend.log compressed with bzip2

[John Finlay <finlay@…>]

mythfrontend crash dump

[robertm]

As mentioned to you on the users list, please submit an actual crash backtrace per the wiki debugging page.

[robertm]

Also, not a mythvideo problem, and please read the ticket howto-- A developer will decide what the deadline for solving a problem, and its severity, is.

[John Finlay <finlay@…>]

Replying to robertm:

As mentioned to you on the users list, please submit an actual crash backtrace per the wiki debugging page.

Isn't that what the crash dump I attached is?

[robertm]

No. Please read the wiki debugging page you were linked on your mailing list thread.

[John Finlay <finlay@…>]

Replying to robertm:

No. Please read the wiki debugging page you were linked on your mailing list thread.

I did and under the section on using ubuntu debug packages in Basic Backtrace it says:

4) When your crash happens, it will ask you to submit a bug report. Submit the full report. You'll need a launchpad account for this.

That didn't happen so I found the crash dump and sent it but I suppose you mean that I'm supposed to run mythfrontend gdb?

[robertm]

We don't have access to Ubuntu's crash report stuf. Presumably their tool has somehow automatically opened a bug report that they will theoretically forward to us-- for *us* to handle the ticket, though, we need a proper backtrace, and yes, that means attaching gdb to a debug build of MythTV *with debug symbols*. (This means you will need to have installed all the debug packages). Install a debug build and follow the normal gdb backtrace steps.

[John Finlay <finlay@…>]

gdb backtrace

[robertm]

This is a SIGABRT, not a SIGSEGV.... did you cause it to crash, or just kill the frontend while it was running? To be clear, the backtrace output needs to be from when you trigger a frontend crash.

[robertm]

Daniel, this appears that it might be a Ringbuffer issue-- can you have a look?

[John Finlay <finlay@…>]

Replying to robertm:

This is a SIGABRT, not a SIGSEGV.... did you cause it to crash, or just kill the frontend while it was running? To be clear, the backtrace output needs to be from when you trigger a frontend crash.

I ran the frontend in gdb and then navigated to start playing an iso image - the frontend rand and then crashed with the info included in the dump. I used the gdbcommands setup listed in the HOW-TO. I did not abort it or otherwise do anything to make it crash. It looks like an assert in some mutex handling code triggered it.

[finlay@…]

I made two iso files from the same dvd but using two different ripping programs (DVDFAB and DVDShrink). The frontend can play the one iso image (DVDFab) just fine but crashes when the other iso image (DVDShrink) is played. I mounted the iso images using loopback devices and md5summed the VIDEO_TS files to see what the difference was. All the .VOB files are identical but the .IFO files are different. I used lsdvd to dump the info about the iso images and the output was the same for both. I suspect that the FE is having a problem reading the .IFO file information and analyzing it.

[skd5aner <skd5aner@…>]

ref #9844 - Possible related?

[mdean]

I'm marking this as a duplicate of #9844, based on:

2011-01-12 14:08:40.047 RingBuf?(myth://Videos@172.20.2.3:6543/Kyle XY/KyleXY_S1_D1.ISO): OpenFile?(myth://Videos@172.20.2.3:6543/Kyle XY/KyleXY_S1_D1.ISO, 2000 ms)

(with capital .ISO). If this is not fixed in current (as of today) -fixes, please re-open with new logs and backtrace. Thanks. (And thank you, skd5aner, for noticing the similarities.)

[mdean]

Just noticed it's confirmed fixed at ​http://www.gossamer-threads.com/lists/mythtv/users/483160#483160