JDK-8238275: Lanai: BasicStroke/DashOffset.java: Unexpected color at 2, 2: ff000000; expected: ff0000ff, ff00ff00

[Gorbarov, Mykola]

Dear Ajit Ghaisas,

The bug inside “java/awt/BasicStroke/DashOffset.java” test is related to drawing blue rectangle into VolatileImage.
The BufferedImage drawing/validation works fine.

For VolatileImage (creating at line 95), the drawRect at 118 draws blue rectangle shifted (with -1, -1).
As result, image validation throws exception:

   Metal support is present

   Exception in thread "main" java.lang.RuntimeException: Unexpected color at 3, 1: ff0000ff; expected: ffffffff

            at DashOffset.checkColor(DashOffset.java:222)

            at DashOffset.checkColor(DashOffset.java:209)

            at DashOffset.checkHorizontalLine(DashOffset.java:151)

            at DashOffset.validate(DashOffset.java:127)

            at DashOffset.main(DashOffset.java:105)

   Metal: Supported, feature set macOS GPUFamily2 v1

See attached volatileImage.png with error. The volatileImageCORRECT.png does not have an error(metal support is off).
Note: sometimes the incorrect image looks like attached volatileImageMETAL.png

WBR, Nick