RFR: 8308875: java/awt/Toolkit/GetScreenInsetsCustomGC/GetScreenInsetsCustomGC.java failed with 'Cannot invoke "sun.awt.X11GraphicsDevice.getInsets()" because "device" is null'

[Maxim Kartashev]

On Mon, 5 Jun 2023 17:51:27 GMT, Phil Race <prr at openjdk.org> wrote:

>> 8308875 is a regression after the recent [fix for 8305578](https://github.com/openjdk/jdk/commit/d7245f70) that effectively undid a part of [another, older, change](https://github.com/openjdk/jdk/commit/40f6d697d25293282e3d3ee695ef8cd9a5494799), the one made to fix [8233573](https://bugs.openjdk.org/browse/JDK-8233573).
>> 
>> This commits brings that part back and passes the test `java/awt/Toolkit/GetScreenInsetsCustomGC/GetScreenInsetsCustomGC.java` on Linux, so the test is also removed from the ProblemList file.
>
> I note that the previous fix "undid" similar code on windows and mac as well.
> Any explanation why it only causes a problem for Linux ?

@prrace 
> I note that the previous fix "undid" similar code on windows and mac as well.
> Any explanation why it only causes a problem for Linux ?

Now that I've looked at the code, I don't understand the statement "the previous fix "undid" similar code on windows and mac as well". If by "the previous fix" you mean the fix for 8305578, then it did *not* introduce the same problem on MacOS/Windows as it did for Linux. Compare the relevant parts of `getScreenInsets()` before this one has been integrated:

Linux:
        final X11GraphicsDevice device = (X11GraphicsDevice) gc.getDevice();
        Insets insets = device.getInsets();

MacOS:
        if (!(gd instanceof CGraphicsDevice)) {
            return super.getScreenInsets(gc);
        }

Windows:
        if (!(gd instanceof Win32GraphicsDevice)) {
            return super.getScreenInsets(gc);
        }


Only Linux will fail in case of a "custom" `GraphicsConfiguration`.

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PR Comment: https://git.openjdk.org/jdk/pull/14170#issuecomment-1597060568