VirtualKeyboard, Program crash when input out of range char to a QLineEdit with validator

[Anima]

@SGaist
Do you have any suggestion? Thank you.

[SGaist]

What if you use the following:

MyDialog::MyDialog(QWidget *parent):
    QDialog(parent)
{
     m_pEdit = new QLineEdit(this);
     m_pEdit->setValidator(new QRegularExpressionValidator(QRegExp(u8"^([0-9]|[1-9][0-9]{1,2})")));
}
 
MyDialog::~MyDialog()
{
}

?

[zhangqinagqiag]

This problem also exists in 5.15.2，As long as it is a pop-up window and uses both virtual keyboard and physical keyboard, it will crash

[SGaist]

Which compiler are you using ?

[Anima]

@SGaist
Thanks.
The issue still exists after set the parent of MyDialog.
The compiler I'm using is Microsoft Visual C++ compiler 14.0.
I also tried MinGW 8.1.0 on Windows 10, got the same issue.

But on Ubuntu 18.04, the same program, built by Qt5.12.10 and g++, works fine. I think it may be a platfrom specific bug.

[SGaist]

Might be indeed.

One last test, what happens if you use open in place of exec ?

[Anima]

@SGaist
I modified the program as below, and still got the same result. Program crashed after I tapped illegal keys with physical keyboard.

void QtGuiApplication1::onBtnClicked()
{
    MyDialog* dlg = new MyDialog(this);
    dlg->open();
}

[SGaist]

Then I would say a bug report is the next step.

[Anima]

The issue is a known bug QTBUG-9304.
Unfortunately, it will not be fixed for Qt5.12.

[SGaist]

From the looks of the patch, you should be able to port it to 5.12 and build the module yourself with it.