winId() and UI events

[allexz]

Hi all,

I have the strange behavior when using QWidget::winId() method (on Windows).
When I used Qt 4.8.4 everything was OK.
But in 5.0.0 and 5.0.1 if I call winId() for one of the child widgets, the first widget in the hierarchy stops responding to UI events.

I created the simple example:

#include <QtWidgets/QApplication>
#include <QtWidgets/QDialog>
#include <QPushButton>
 
QDialog *dialog1;
QDialog *dialog2;
 
QPushButton *button1;
QPushButton *button2;
 
void Button2_clicked()
{
	WId hwnd = button2->winId();
}
 
void Button1_clicked()
{
	dialog2 = new QDialog(dialog1);
	dialog2->resize(120, 30);
 
	button2 = new QPushButton("Button2", dialog2);
	QObject::connect(button2, &QPushButton::clicked, Button2_clicked);
 
	dialog2->exec();
	delete dialog2;
}
 
int main(int argc, char *argv[])
{
	QApplication a(argc, argv);
 
	dialog1 = new QDialog;
	dialog1->resize(200, 50);
 
	button1 = new QPushButton("Button1", dialog1);
	QObject::connect(button1, &QPushButton::clicked, Button1_clicked);
 
	dialog1->exec();
	delete dialog1;
 
	return 0;
}

#include <QtWidgets/QApplication>
#include <QtWidgets/QDialog>
#include <QPushButton>

QDialog *dialog1;
QDialog *dialog2;

QPushButton *button1;
QPushButton *button2;

void Button2_clicked()
{
	WId hwnd = button2->winId();
}

void Button1_clicked()
{
	dialog2 = new QDialog(dialog1);
	dialog2->resize(120, 30);

	button2 = new QPushButton("Button2", dialog2);
	QObject::connect(button2, &QPushButton::clicked, Button2_clicked);

	dialog2->exec();
	delete dialog2;
}

int main(int argc, char *argv[])
{
	QApplication a(argc, argv);

	dialog1 = new QDialog;
	dialog1->resize(200, 50);

	button1 = new QPushButton("Button1", dialog1);
	QObject::connect(button1, &QPushButton::clicked, Button1_clicked);

	dialog1->exec();
	delete dialog1;

	return 0;
}

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Scenario 1:

1. Press "button1" in first dialog - second dialog appears.
2. Close second dialog.
3. Press "button1" again - it works.

Scenario 2:

1. Press "button1" in first dialog - second dialog appears.
2. Press "button2" in first dialog - called void Button2_clicked() { WId hwnd = button2->winId(); }
2. Close second dialog.
3. Press "button1" again - don't pressed.

I have the same behavior if use QMainWindow and QWidget instead of QDialogs.

Windows 7 x64 Pro
Qt 5.0.1 (5.0.0 - the same)
Visual Studio 2010 SP1
Qt5 Visual Studio Add-in

[allexz]

So, nobody have any ideas? Or nobody can reproduce this?
It's a pity, because I can not use winId() because of this...