[Win32] Showing a directory chooser prevents sending events for other shells

[tmssngr]

Describe the bug
If a directory chooser is shown on top of one shell, the event handling of other shells is dysfunctional.

To Reproduce
Run this snippet:

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

public class DirectoryChooserOpenRepaintProblem {

	public static void main(String[] args) {
		final Display display = new Display();
		final Shell shell = new Shell(display);
		shell.setLayout(new GridLayout(1, true));

		final Table table = new Table(shell, SWT.BORDER | SWT.MULTI);
		table.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
		for (int i = 0 ; i < 10; i++) {
			new TableItem(table, SWT.NONE).setText("row " + i);
		}

		table.addListener(SWT.Selection, even -> {
			final int[] selectionIndices = table.getSelectionIndices();
			String text = selectionIndices.length == 1
					? "row " + selectionIndices[0]
					: selectionIndices.length + " rows";
			text += " selected";
			System.out.println(text);
		});

		shell.setSize(400, 300);
		shell.open();

		final Shell shell2 = new Shell(display);
		shell2.setLayout(new FillLayout());

		final Button button = new Button(shell2, SWT.PUSH);
		button.setText("Open Directory");
		button.addListener(SWT.Selection, even -> {
			final DirectoryDialog dialog = new DirectoryDialog(shell2, SWT.PRIMARY_MODAL | SWT.SHEET);
			dialog.setText("Open Directory");
			dialog.setMessage("Select the dir");
			dialog.open();
		});

		shell2.setSize(400, 200);
		shell2.open();

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

It will two shells. One shows a Table control. Selecting something in the table will show a brief summary in the terminal. The other shows a button. Clicking that will show a directory chooser.

• select different rows in the table
• -> the terminal will show a selection summary
• in the second shell, click the button to open the directory chooser
• keep the directory chooser open and switch back to the first shell
• select different rows in the table
• -> the terminal will not show anything
• select different rows in the table
• close the directory chooser
• -> now the terminal spits out the cached selection events

Expected behavior
Either the other shell's listeners should behave correctly (similar to no shown directory chooser). Or show the directory chooser application modal.

Screenshots

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)
   Windows 11 23H2

Workaround (or) Additional context
No known workaround.