[GTK] MouseMove-events are not sent after showing popup

[tmssngr]

Describe the bug
After showing a popup menu and closing it, mouse move events are not sent any more (if a mouse down and drag detected listener are registered).

To Reproduce

import org.eclipse.swt.*;
import org.eclipse.swt.widgets.*;

public class NoMouseEventsAfterShowingPopup {

	public static void main(String[] args) {
		final Display display = new Display();

		final Shell shell = new Shell(display);
		shell.addListener(SWT.MouseMove, event -> {
			System.out.println("mouse moved " + System.currentTimeMillis() % 1000);
		});

		// these listeners prevent mouse move events after showing the popup:
		shell.addListener(SWT.MouseDown, event -> {
			System.out.println("mouse down");
		});
		shell.addListener(SWT.DragDetect, event -> {
			System.out.println("drag detected");
		});
		// <<

		shell.addListener(SWT.MenuDetect, event -> {
			final Menu menu = new Menu (shell, SWT.POP_UP);
			final MenuItem item = new MenuItem (menu, SWT.PUSH);
			item.setText ("Popup");
			menu.setLocation(event.x, event.y);
			menu.setVisible(true);
		});

		shell.setSize(300, 200);
		shell.open();

		while (!shell.isDisposed()) {
			if (!display.readAndDispatch()) {
				display.sleep();
			}
		}

		display.dispose();
	}
}

• move the mouse over the shell -> events are logged to the console
• right-click to show a minimal popup menu
• close the popup menu with ESC
• move the mouse again -> no events are logged any more
• left-click into the shell
• move the mouse again -> now events are logged again

Expected behavior
MouseMove events should be sent independent of whether

• drag-detect and mouse-down listeners are configured
• a popup menu has been shown

Screenshots
https://github.com/user-attachments/assets/2947081d-397c-44c7-8b45-b5f7f138dab0

Environment:

1. Select the platform(s) on which the behavior is seen:

• • All OS
• • Windows
• • Linux
• • macOS

2. Additional OS info (e.g. OS version, Linux Desktop, etc)
   Ubuntu 26.04