Ensure font is fetched from registry even when zoom levels match

[arunjose696]

This change ensures font is fetched from registry even when zoom levels match.

The font returned by Font.win32_new is stored in the setFont() method of widgets. Previously, if targetZoom == font.zoom, the passed font was returned directly. However, the passed font could have been disposed by user code. This change ensures that the font is always fetched from the font registry, even when the zoom levels match, avoiding potential use of disposed fonts.

Steps to reproduce

The below snippet fails on master. And passes with the change

package org.eclipse.swt.snippets;
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;

public class CanvasCaretFocus {
    public static void main(String[] args) {
        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setSize(300, 200);
        shell.setText("Canvas Caret Focus");
        Canvas canvas = new Canvas(shell, SWT.BORDER);

        shell.open();
        Caret caret = new Caret(canvas, SWT.NONE);
        Font font = new Font(display, "Default", 10, SWT.BOLD);
    	caret.setFont(font );
    	font.dispose();

    	canvas.setFocus();
        canvas.setCaret(caret);



    }
}

[github-actions]

Test Results

   539 files   -  7     539 suites   - 7   30m 23s ⏱️ +57s
 4 358 tests  - 54   4 318 ✅  - 77   14 💤  - 3  25 ❌ +25  1 🔥 +1 
16 664 runs   - 54  16 514 ✅  - 77  124 💤  - 3  25 ❌ +25  1 🔥 +1 

For more details on these failures and errors, see this check.

Results for commit 7f78dde. ± Comparison against base commit 7b46268.

This pull request removes 54 tests.

AllWin32Tests ImageWin32Tests ‑ testDisposeDrawnImageBeforeRequestingTargetForOtherZoom
AllWin32Tests ImageWin32Tests ‑ testDrawImageAtDifferentZooms(boolean)[1] true
AllWin32Tests ImageWin32Tests ‑ testDrawImageAtDifferentZooms(boolean)[2] false
AllWin32Tests ImageWin32Tests ‑ testImageDataForDifferentFractionalZoomsShouldBeDifferent
AllWin32Tests ImageWin32Tests ‑ testImageShouldHaveDimesionAsPerZoomLevel
AllWin32Tests ImageWin32Tests ‑ testRetrieveImageDataAtDifferentZooms(boolean)[1] true
AllWin32Tests ImageWin32Tests ‑ testRetrieveImageDataAtDifferentZooms(boolean)[2] false
AllWin32Tests TestTreeColumn ‑ test_ColumnOrder
AllWin32Tests Test_org_eclipse_swt_dnd_DND ‑ testByteArrayTransfer
AllWin32Tests Test_org_eclipse_swt_dnd_DND ‑ testFileTransfer
…

♻️ This comment has been updated with latest results.

[HeikoKlare]

Since you already have a simple reproducing snippet, maybe you could use that to add a regression test, so that we might see such a bug more early in the future?

[arunjose696]

Closing this as I have opened a different PR which fixes this issue

• [Win32] Do not set IME font if the font is disposed #2365