Bug 218282 – rendering to an offscreen framebuffer alterates canvas display

• Component: WebGL
• Status: RESOLVED DUPLICATE

Created attachment 412522 [details]
sample reproducing the pb

See attached sample.

1/ create a canvas
2/ create an webgl context 
3/ clear with black color

4/ create an offscreen framebuffer to render to a texture
5/ clear with black color in a setTimeout callback

Result : the canvas switch to transparent

Expected result : the canvas should remain black

Maybe similar to https://bugs.webkit.org/show_bug.cgi?id=218177 or related bugs

[Smoley]

I can reproduce this on an iPad running iOS 14 GM, but this appears to be fixed on the iOS 14.2 Beta https://developer.apple.com/news/releases/?id=10132020b

Are you able to reproduce this on the latest beta build as well?

[Kenneth Russell]

I think this is a duplicate of Bug 218177 which Kimmo just fixed. Kimmo, can you confirm?

(In reply to Smoley from comment #1)
> I can reproduce this on an iPad running iOS 14 GM, but this appears to be
> fixed on the iOS 14.2 Beta
> https://developer.apple.com/news/releases/?id=10132020b
> 
> Are you able to reproduce this on the latest beta build as well?

I will give it a try on the real scenario failing, give me some time, we have a restricted number of iOS devices. Thanks.

[Kimmo Kinnunen]

Thanks for the report.
With tip of the tree, the canvas is showing black on screen.
Yes, this should be fixed by the fix in bug 218177.

*** This bug has been marked as a duplicate of bug 218177 ***