[mythtv] [mythtv-commits] Ticket #12917: mythfrontend.real crashes since Ubuntu 16.10 upgrade

[Roger Siddons]

On 15/11/16 15:43, MythTV wrote:
> #12917: mythfrontend.real crashes since Ubuntu 16.10 upgrade
> -----------------------------------------+--------------------------
>  Reporter:  heynnema@…                   |          Owner:  pbennett
>      Type:  Bug Report - General         |         Status:  closed
>  Priority:  critical                     |      Milestone:  unknown
> Component:  MythTV - General             |        Version:  0.28.0
>  Severity:  high                         |     Resolution:  fixed
>  Keywords:  mythfrontend stack smashing  |  Ticket locked:  0
> -----------------------------------------+--------------------------
>
> Comment (by pbennett):
>
>  The problem with ref counting is that the QNetworkAccessManager deletes
>  the QNetworkConfiguration internally, so we cannot make it call the
>  decrease reference method instead of calling delete.
>
>  If this fix is OK, I should go to the other QNetworkAccessManager
>  instances in the system and make them use their own QNetworkConfiguration
>  instances, so that each one has its own configuration object and they can
>  safely be deleted.
>
> --
> Ticket URL: <https://code.mythtv.org/trac/ticket/12917#comment:30>

Looks like it's related to
https://bugs.launchpad.net/ubuntu/+source/qtbase-opensource-src/+bug/1630941
and
https://codereview.qt-project.org/#/c/172173/

The stack trace goes through ~QScopedPointer (it will destroy itself) so 
I don't see why MythNetworkAccessManager needs to delete it anyway.

It may still segfault if we take the delete out, but that's a Qt issue 
that's fixed in 5.7. I saw a discussion about backporting it to 5.6.x 
but I didn't read far. And I think Ubuntu may have patched it already.