Re: [Plplot-devel] Testing of latest qt pushes requested

[António R. T. <ar...@gm...>]

Hi Alan
let's do a small change in qt_example. cpp to make it more orthodox.

   QApplication a( argc, argv );
    PlotWindow   win ( Argc, Argv );
    win.show();

when I do this the program always crashes on close in my system.
much likely because there is an attempt to free twice a memory block.
It may result from

setAttribute( Qt::WA_DeleteOnClose );
 on qt_Plotwindow.cpp as at destructor level qt may try to free something
that the driver has already  free.
the fact is if I erase or comment that line the program does not crash
anymore on exit.

cheers,

p.s
I will have a look at your commit and test it on my own applications




On Sun, Dec 30, 2018 at 9:58 PM Alan W. Irwin <Ala...@gm...>
wrote:

> Hi António:
>
> I have just pushed your change and my subsequent followup to make the
> initQtApp and close QtApp code easier to read and more robust.
>
> Please look carefully at the code changes in my last commit
> (plplot-5.14.0-15-g790754f35) and also test those changes to make sure
> they work fine for your use case (qt applications using qt devices).
>
> Unless you find something that needs changing with that last commit,
> that should complete our joint qt development work until you have
> a chance to work on PLplot again in a couple of months.
>
> However, ideally it would be good to not have to wait that long for
> the resolution of the occasional segfaults on exit for qt_example that
> I encountered when comprehensive testing 5.14.0. So now that I
> understand our qt device driver and binding a bit better, I am going
> to look at that issue again.  And if I can find a simple fix, I will
> commit that, but if I still cannot find such a simple fix (as happened
> during the 5.14.0 release because I am still in the early stages of
> learning C++ and Qt), I will leave that (more complex?) fix to you in
> a couple of months.
>
> Alan
> __________________________
> Alan W. Irwin
>
> Programming affiliations with the FreeEOS equation-of-state
> implementation for stellar interiors (freeeos.sf.net); the Time
> Ephemerides project (timeephem.sf.net); PLplot scientific plotting
> software package (plplot.sf.net); the libLASi project
> (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
> and the Linux Brochure Project (lbproject.sf.net).
> __________________________
>
> Linux-powered Science
> __________________________
>


-- 

António Rodrigues Tomé
Universidade da Beira Interior
Instituto D. Luís (lab associado)
email address:
ar...@gm...
ar...@ub...
http://www.researcherid.com/rid/A-5681-2013