QwtPolar 1.0.0 examples crash when exiting

[jecaro]

Hi there,

I've just compiled latest QwtPolar (1.0.0) with Qwt 6.0.1 and Qt 4.7.4 on windows using VC9. The two examples crashes when the application ends. It crashes in the function:

QwtLegend::remove

Anyone coming across this issue ? Does anyone has an idea to get around this problem.

Thanks,

Jean-Charles

[Uwe]

Start your debugger and show the call stack,

Uwe

[jecaro]

From polardemo:

> qwtd.dll!QwtLegend::remove(const QwtLegendItemManager * plotItem=0x00ac11d0) Ligne 384 + 0x7 octets C++
qwtpolard.dll!QwtPolarItem::attach(QwtPolarPlot * plot=0x00000000) Ligne 83 C++
qwtpolard.dll!QwtPolarItemDict::detachItems(int rtti=0, bool autoDelete=true) Ligne 151 C++
qwtpolard.dll!QwtPolarItemDict::~QwtPolarItemDict( ) Ligne 86 C++
qwtpolard.dll!QwtPolarPlot::~QwtPolarPlot() Ligne 104 + 0xf octets C++
polardemo.exe!Plot::~Plot() + 0x10 octets C++
polardemo.exe!Plot::`scalar deleting destructor'() + 0xf octets C++
QtCored4.dll!QObjectPrivate::deleteChildren() Ligne 1936 + 0x24 octets C++
QtGuid4.dll!QWidget::~QWidget() Ligne 1634 C++
polardemo.exe!QWidget::`scalar deleting destructor'() + 0x10 octets C++
QtCored4.dll!QObjectPrivate::deleteChildren() Ligne 1936 + 0x24 octets C++
QtGuid4.dll!QWidget::~QWidget() Ligne 1634 C++
QtGuid4.dll!QMainWindow::~QMainWindow() Ligne 370 + 0x22 octets C++
polardemo.exe!MainWindow::~MainWindow() + 0x10 octets C++
polardemo.exe!main(int argc=1, char * * argv=0x00a07820) Ligne 12 + 0x15 octets C++
polardemo.exe!WinMain(HINSTANCE__ * instance=0x00400000, HINSTANCE__ * prevInstance=0x00000000, char * __formal=0x00151f23, int cmdShow=1) Ligne 132 + 0x12 octets C++
polardemo.exe!__tmainCRTStartup() Ligne 578 + 0x35 octets C
polardemo.exe!WinMainCRTStartup() Ligne 403 C

and spectrogram:

> qwtd.dll!QwtLegend::remove(const QwtLegendItemManager * plotItem=0x00ac18f8) Ligne 384 + 0x7 octets C++
qwtpolard.dll!QwtPolarItem::attach(QwtPolarPlot * plot=0x00000000) Ligne 83 C++
qwtpolard.dll!QwtPolarItemDict::detachItems(int rtti=0, bool autoDelete=true) Ligne 151 C++
qwtpolard.dll!QwtPolarItemDict::~QwtPolarItemDict( ) Ligne 86 C++
qwtpolard.dll!QwtPolarPlot::~QwtPolarPlot() Ligne 104 + 0xf octets C++
spectrogram.exe!Plot::~Plot() + 0x10 octets C++
spectrogram.exe!Plot::`scalar deleting destructor'() + 0xf octets C++
QtCored4.dll!QObjectPrivate::deleteChildren() Ligne 1936 + 0x24 octets C++
QtGuid4.dll!QWidget::~QWidget() Ligne 1634 C++
spectrogram.exe!PlotWindow::~PlotWindow() + 0x10 octets C++
spectrogram.exe!PlotWindow::`scalar deleting destructor'() + 0xf octets C++
QtCored4.dll!QObjectPrivate::deleteChildren() Ligne 1936 + 0x24 octets C++
QtGuid4.dll!QWidget::~QWidget() Ligne 1634 C++
QtGuid4.dll!QMainWindow::~QMainWindow() Ligne 370 + 0x22 octets C++
spectrogram.exe!MainWindow::~MainWindow() + 0x10 octets C++
spectrogram.exe!main(int argc=1, char * * argv=0x00a07820) Ligne 67 + 0x15 octets C++
spectrogram.exe!WinMain(HINSTANCE__ * instance=0x00400000, HINSTANCE__ * prevInstance=0x00000000, char * __formal=0x00151f25, int cmdShow=1) Ligne 132 + 0x12 octets C++
spectrogram.exe!__tmainCRTStartup() Ligne 578 + 0x35 octets C
spectrogram.exe!WinMainCRTStartup() Ligne 403 C

It seems the same issue.

[Uwe]

Well, the crash doesn't happen on my linux box, but my guess is, that the legend is already destructed when the plot items are going to be removed.

I have added the following line to the destructor of QwtPolarPlot:

QwtPolarPlot::~QwtPolarPlot()
{
    detachItems( QwtPolarItem::Rtti_PolarItem, autoDelete() );
    ...
}

QwtPolarPlot::~QwtPolarPlot()
{
    detachItems( QwtPolarItem::Rtti_PolarItem, autoDelete() );
    ...
}

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Please do the same and let me know if the crash is gone.

Uwe

[jecaro]

Hi Uwe,

I've just tried with this additional line and it doesn't crash any more, well done !
Thanks a lot for your help.
Cheers,

Jean-Charles