Bug 230625 – fast/mediastream/captureStream/canvas3d.html succeeds on bots surprisingly, as the underlying code is broken

• Status: NEW
• Component: WebRTC

[Kimmo Kinnunen]

fast/mediastream/captureStream/canvas3d.html does not seem to be part of any test expectation

* The test fails
* I cannot see where the test is not marked as failing (?)
* The underlying code was not fixed

[Alexey Proskuryakov]

It somehow passes on the bots: https://results.webkit.org/?suite=layout-tests&test=fast%2Fmediastream%2FcaptureStream%2Fcanvas3d.html

[Radar WebKit Bug Importer]

<rdar://problem/83668855>

[Kimmo Kinnunen]

So the bug was that due to reading the drawing buffer of webgl, the iosurface would be read as uninitialised.
Uninitialised IOSurfaces appear red.

The test does not test that captured WebGL image is certain pattern. It tests that the captured image is not black. As such, it was fooled by the red.

Eventually the test should be improved to draw some common test pattern (such as subset of the bip-bop image) and then common test pattern verification code should be used to verify that the image was received as intended.