tree 3f870d157c42f844998beb2d2fbdd02c3b0f8a12
parent 6250e992ac750edc5994a0712fdb6e6f6636ffe3
author Justin Novosad <junov@chromium.org> 1647275038 -0700
committer Blink WPT Bot <blink-w3c-test-autoroller@chromium.org> 1647275829 -0700

Fix canvas clearRect with alpha:false context attribute

Before this fix, clearRect was setting the alpha values of canvas
pixels to 0 despite the alpha context attribute being set to false.
The proper behavior, as required by the spec is to force the alpha
value to 1.0 (e.g. 255) when the alpha context attribute is false
See: https://html.spec.whatwg.org/#concept-canvas-alpha

This CL also improves test coverage for alpha:false use cases.

Bug: 1303948
Change-Id: I8c94840d108441adabd5185be500b5dc46717381
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3514218
Reviewed-by: Aaron Krajeski <aaronhk@chromium.org>
Commit-Queue: Justin Novosad <junov@chromium.org>
Cr-Commit-Position: refs/heads/main@{#980586}