Crash (segmentation violation) on QCoreApplication_SendEvent

[ilius]

qt6.QCoreApplication_SendEvent causes a crash with *qt.QKeyEvent, but only when PageUp or PageDown is pressed with Alt or Ctrl.

func (app *Application) setupKeyPressEvent(widget KeyPressIface) {
	widget.OnKeyPressEvent(func(super func(event *qt.QKeyEvent), event *qt.QKeyEvent) {
		switch event.Key() {
		case int(qt.Key_PageUp), int(qt.Key_PageDown):
			// crashes (even with recover) if if event.Modifiers() > 0
			// qt.QCoreApplication_SendEvent(app.articleView.Browser.QObject, event.QEvent)
			qt.QCoreApplication_SendEvent(app.entry.QObject, event.QEvent)
		}
	})
}

go.mod: github.com/mappu/miqt v0.11.2
Qt 6.4.2
Go 1.24.6

My code: https://github.com/ilius/ayandict/blob/v3/pkg/application/app_handlers.go#L109

Full stderr log attached.
err.log

[mappu]

Hmm, I can't reproduce it yet. With a simple standalone app using OnKeyPressEvent, the event works correctly with ctrl, alt, pageup and pagedown. It works with forwarding it to another widget, and also with consuming the event directly.

package main

import (
	"fmt"
	"log"
	"os"

	qt "github.com/mappu/miqt/qt6"
)

func main() {

	qt.NewQApplication(os.Args)

	input1 := qt.NewQLineEdit2()
	input1.SetFixedWidth(320)
	input1.SetText("i am input1")
	input1.Show()

	input2 := qt.NewQLineEdit2()
	input2.SetFixedWidth(320)
	input2.SetText("i am input2")
	input2.Show()

	input1.OnKeyPressEvent(func(super func(event *qt.QKeyEvent), event *qt.QKeyEvent) {
		log.Printf("keyPressEvent key=%d modifiers=%d", event.Key(), event.Modifiers())

		switch event.Key() {
		case int(qt.Key_PageUp), int(qt.Key_PageDown):
			log.Printf("got pageup/pagedown")

		}

		// Forward event to another widget
		qt.QCoreApplication_SendEvent(input2.QObject, event.QEvent)

		// Or, handle it natively
		// super(event)
	})

	qt.QApplication_Exec()

	fmt.Println("OK!")
}

I'm not sure what's different in your application,

While testing this, i very suddenly learned that Ctrl+Alt+Shift+Pageup and Ctrl+Alt+Shift+Pagedown are default keyboard shortcuts in KDE for: shutdown and reboot. 😆