Bug 205666 – REGRESSION (r253926): webgl/2.0.0/conformance2/transform_feedback/unwritten-output-defaults-to-zero.html is a flaky failure

• Status: NEW
• Component: WebGL

[Alexey Proskuryakov]

webgl/2.0.0/conformance2/transform_feedback/unwritten-output-defaults-to-zero.html became a very frequent flaky failure after the switch to ANGLE. This affects all hardware/software configurations.

https://results.webkit.org/?suite=layout-tests&test=webgl%2F2.0.0%2Fconformance2%2Ftransform_feedback%2Funwritten-output-defaults-to-zero.html

@@ -5,7 +5,7 @@
 [ 2: PASS ] getError was expected value: NO_ERROR : Set up program should succeed
 [ 3: FAIL ] buffer should match expected values
 [ 4: PASS ] getError was expected value: NO_ERROR : Set up program should succeed
-[ 5: PASS ] buffer should match expected values
+[ 5: FAIL ] buffer should match expected values
 [ 6: PASS ] successfullyParsed is true
-[ FAIL ] 1 failures reported
+[ FAIL ] 2 failures reported

[Radar WebKit Bug Importer]

<rdar://problem/58257079>

[Justin Fan]

A proper implementation that makes this test completely PASS on ANGLE backend has been landed since the last time we attempted to enable ANGLE by default, so this should not occur anymore. I'm unable to reproduce any flakiness on iMac Pro.