Browser, WebView2 update to 135.0.3179.73: PDF Viewer in child window not saving correctly

[jensppi]

Describe the bug
Open Browser component with URL https://de.wikipedia.org/wiki/Datei:Test.pdf.

With Ctrl-Click on the small colorful TEST.pdf preview, a new window opens with the title Test.pdf. It contains the embedded PDF viewer from Edge WebView2.

• Issue: Click on the disk icon to save the file. Choose a location and save the file. Open that folder via Explorer. No file was saved!

• Alternative attempt: Click the printer icon, choose "Save as PDF", and save. File appears saved at first. But after closing the PDF viewer window, the file disappears — it's only temporarily available while the application is running!

To Reproduce

    import org.eclipse.swt.SWT;
    import org.eclipse.swt.browser.Browser;
    import org.eclipse.swt.widgets.Display;
    import org.eclipse.swt.widgets.Shell; 
    public class SWTBrowserExample {

    public static void main(String[] args) {

        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setText("Wikipedia PDF Viewer - WebView2");
        shell.setSize(1024, 768);

        try {
            Browser browser = new Browser(shell, SWT.NONE);

            String wikiUrl = "https://de.wikipedia.org/wiki/Datei:Test.pdf";
            browser.setUrl(wikiUrl);

            browser.setBounds(0, 0, shell.getSize().x, shell.getSize().y);
        } catch (Throwable e) {
            System.err.println("Error on init: " + e.getMessage());
            display.dispose();
            return;
        }

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

Expected behavior
All save operations should create real, persistent files on disk.
Saving via the disk or print-to-PDF options should not result in temporary or deleted files.

Screenshots

Environment

• Windows 11
• Most important: Update to WebView2 135.0.3179.73

JRE/JDK version
Tested with Java 21, but issue is independent of Java version.

Tested with

• SWT 4.28
• SWT 4.36M1

[jensppi]

It is not specific to the embedded pdf viewer.

If you scroll down on the Wiki page to Test.gif and do a Ctrl-Click on the link 'Test.gif', a new window opens. From the context menu try a 'Save image as' on the image. It also fails.

In the root window 'Save image as' is working. It fails in child windows opened via 'Ctrl-Click'.

[jensppi]

Seems to be a WebView2 problem: see MicrosoftEdge/WebView2Feedback#5199 and MicrosoftEdge/WebView2Feedback#5196

[jensppi]

It is a WebView2 bug.

[HeikoKlare]

Thank you for sharing the issue and the insights, @jensppi! Very helpful to have this documented in case someone experiences this issue when using Eclipse/SWT.