Mixxx crashes on hotcue_X_set

[Hendrik]

After a long break I installed build 6219 and used my own skin.
My skin has 36 hotcues with 36 custom marker in the visual-widget.
Whenever I wanted to set a hotcue, Mixxx crashed with the following message:

Fatal [Main]: ASSERT failure in QList <T> :: operator []: "index out of range", file /usr/include/qt4/QtCore/qlist.h, line 473

The official skins are not affected, because they use only 4 or 8 visible hotcues.

The crash can be reproduced, when you add more custom marker blocks in the visual-widget and set a hotcue via gui or developer-tools.
In my case approx. hotcue 15.

This "bug" was caused by a change between build 5849 and 6219.

Ubuntu 14.04.5 LTS
AMD Phenom(tm) II X6 1090T Processor
NVIDIA Corporation GM107 [GeForce GTX 750 Ti] [10de:1380] (rev a2)
4.5.0 NVIDIA 367.57
Qt: 4.8.6
KDE: 4.13.3

[Be (be.ing)]

I cannot reproduce this by setting hotcue_X_set via Developer Tools with Deere. Is that the same for you? Does the crash only occur with your custom skin? If so, please attach the skin files that have the <Visual> and <Overview> XML elements.

[Hendrik (index82)]

Ok, now i extended the original deere files with additional marker-blocks and hotcue buttons.

1. copy the attached files in the deere skin folder
2. start mixxx
3. change the waveform to stystem-filtered
4. Skin Settings >> Show More Hotcues
5. load an clean track in deck1
6. set one or more hotcues via the hotcue buttons
In my case mixxx closed immediately

other approach
steps 1. - 4. see above
5. load a track with some hotcues in it in deck1
In my case mixxx closed immediately

I figuerd out that only the <visual> is affected.
The <overview> produce no crashes eg. in the sampler.
Change the waveform to "empty" and no chrashes will occur.

I think the length of the templatefile or the number of marker-blocks are relevant.

[Hendrik (index82)]

Could anyone confirm this with the Deere Skin?

[Daniel Schürmann (daschuer)]

I have just tried your receipt using the current master r6224 and I am not able to reproduce it.
Please provide a backtrace of the crash.

https://www.mixxx.org/wiki/doku.php/creating_backtraces

[Hendrik (index82)]

Hi Daniel,

attached you will find the backtrace.I hope it is complete.

Build: r6224
Skin: Deere with the two patch files from above

[Daniel Schürmann (daschuer)]

Thank you for the backtrack.
Unfortunately it contains no debug symbols.
Where do you get the binary from?

[Hendrik (index82)]

http://downloads.mixxx.org/builds/master/release/mixxx-2.1.0-alpha-pre-master-git6224-release-trusty-amd64.deb

[Hendrik (index82)]

That's true.
I have run gdb again and it says ...

hendrik@mixxx:~$ gdb mixxx
GNU gdb (Ubuntu 7.7.1-0ubuntu5~14.04.2) 7.7.1
[...]
Reading symbols from mixxx...(no debugging symbols found)...done.
(gdb)

[Hendrik (index82)]

With try and error I could limit the situation.
The problem exists since PR#992 and build r5903.

BTW the development builds for debian/ubuntu are compiled without debugging symbols since November 2016, I think.

So I compiled on UBUNTU 16.04 LTS.
Attached the back-trace with terminal output. Please take a look.

Thanks in advance.

[Daniel Schürmann (daschuer)]

I could reproduce the issue by loading a track with stored CuePoints.
Here is a fix:
https://github.com/mixxxdj/mixxx/pull/1236

[Hendrik (index82)]

It's fixed.
Thank you very much for taking care of this issue.

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/8828