RFR: JDK-8365426 : [macos26] Graphics2D tests fail on new macOS 26

[Harshitha Onkar]

On Fri, 14 Nov 2025 06:20:08 GMT, Sergey Bylokhov <serb at openjdk.org> wrote:

>> test/jdk/java/awt/Graphics2D/CopyAreaOOB.java line 73:
>> 
>>> 71:         try {
>>> 72:             if (!Platform.isOSX()) {
>>> 73:                 TOLERANCE = PRIMARY_TOLERANCE;
>> 
>> I could set tolerance and primary_tolerance both to zero on other platforms although I have currently set it to a small delta of 2. I can change it to zero if any reviewers suggest that exact color compare would be better.
>
> What is the reason for the color mismatch? Is it possible to check whether it is caused by the rendering pipeline (for example, different colors between metal and ogl), by the native code used by robot (we could compare it with a native screencapture tool), by the code that converts the native image to Java (using Robot.createMultiResolutionScreenCapture might help), or by some blending at the edges of the rendered area?

Couple of observations

- The test fails irrespective of whether opengl or metal pipeline is used
- The color inconsistency is not only at the edges but at random points (can be checked by enabling DEBUG in the test)
- Apple introduced Metal 4 APIs on Apple macOS26 but this can be eliminated as the root cause since the issue occurs on macOS26 x64 as well and when using opengl.
- Setting color profile to sRGB doesn't work either.
- One probable cause could be that CRobot uses deprecated [CGWindowListCreateImage](https://developer.apple.com/documentation/coregraphics/cgwindowlistcreateimage(_:_:_:_:)?language=objc) for screencapture and the recommended new API is ScreenCaptureKit.

Currently the test fails on CI (macOS26) creating noise and adding a color tolerance is the best workaround for now until the root cause or the new feature/setting which is causing the issue on macOS26 is found. I'll create a new JBS issue to track it.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28312#discussion_r2529204369