Review Request: Quit Eventloop before emitting finished and result signals

[Raphael Kubo da Costa]

On Wednesday 11 November 2009 16:38:42 Sebastian Sauer wrote:
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> http://reviewboard.kde.org/r/2140/
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> 
> Review request for kdelibs.
> 
> 
> Summary
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> 
> If KJob::exec is called then it can happen that the result(KJob*) signal is
>  emitted before the QEventLoop in KJob::exec is quit. If a slot connected
>  with the result(KJob*) signal does then e.g. call the same KJob::exec
>  again then funny things may happen. The patch introduces a new internal
>  signal that is called before the finished and result signals are emitted
>  and that quits the eventloop. This way we can be sure that the finished
>  and result signals are always emitted once the eventloop is done.
> 
> 
> Diffs
> -----
> 
>   /trunk/KDE/kdelibs/kdecore/jobs/kjob.h 1047234
>   /trunk/KDE/kdelibs/kdecore/jobs/kjob.cpp 1047234
> 
> Diff: http://reviewboard.kde.org/r/2140/diff
> 
> 
> Testing
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> 
> 
> Thanks,
> 
> Sebastian
> 
I believe this commit is causing bug 217836: basically, d->eventLoop::quit() 
is called inside KJob::emitResult(), however the slot connected to the 
result() signal is called long after the method which called KJob::exec() 
finished, thus causing a segfault because the slot tries to access data that's 
no longer present.

If I use my own QEventLoop instead of calling KJob::exec() or revert this 
commit, the segfault doesn't happen.

Am I doing something unusual here?