Red lines appears in some webites[Bug]

[jawadalkassim]

Steps to reproduce

Launch Fenix Go to Github.com

Expected behavior

Website should look normal

Actual behavior

Device information

• Device vendor / model and Android version: Samsung A12 / Android 11
• Firefox for Android version: 89.1.1

Other Browsers Works fine like Vivaldi and Brave

┆Issue is synchronized with this Jira Task

[jawadalkassim]

I thought it might be fixed in Nightly But it's also there

[SoftVision-LorandJanos]

Hi @jawadalkassim ! Thank you for your report! I am not able to reproduce the issue you described. Do you have webrender active? I know about a similar issue there. Maybe check if it still reproduces if you clear your data. Thank you! Tested on the latest Nightly (91.0a1 2021-06-30T05:09:53.235) and on Release 89.1.1 (Build #2015812947). Devices used: Motorola Nexus 6 (Android 7.1.1), Samsung Galaxy Tab 3 (Android 9), Google Pixel 4 (Android 11).

[jawadalkassim]

Hi @SoftVision-LorandJanos It's Only happening with Firefox I tested Vivaldi and Brave And Samsung Internet All good,

I think webrender is disabled by default Firefox Nightly Version : 91.0a1 (Build #2015819019) Stable and Beta have the same issue

[kbrosnan]

Moved to bugzilla: https://bugzilla.mozilla.org/show_bug.cgi?id=1719345

Change performed by the Move to Bugzilla add-on.

[jamienicol]

@jawadalkassim could you please got to about:support, click "copy text to clipboard", and attach the text to this bug? Thanks.

[jawadalkassim]

@jamienicol https://pastebin.com/DhyQ7A7i

firefox.txt

[jamienicol]

I have been able to reproduce this on github, but not at all reliably. @jawadalkassim does this happen every single time you open github or fotmob.com? Have you noticed it on any other websites? If so, please let me know which ones! hopefully I'll have better luck with some other websites.

[jawadalkassim]

@jamienicol Sometimes websites load normally, Also with Apkmirror.com (Apps icon, sometimes doesn't load and show black and red instead) Duckduckgo.com (with dark theme also Red line) But it's not happening all the time

[jawadalkassim]

89.1.1 (Build #2015812947) AC: 75.0.22, 5204f4025 GV: 89.0-20210527174632 AS: 74.0.1

[jamienicol]

@jawadalkassim apologies for the long delay getting back to you on this one. It turned out to be very tricky to find out what the issue was. I'm still not 100% sure to be honest, but it's definitely a bug in the PowerVR GPU driver and I think I have a workaround.

If you're interested: Basically to render a page we store certain elements in offscreen texture caches, such as images and borders. Additionally, to render certain elements such as the rounded rectangles and circular images, we first have to render an alpha mask in the desired shape to a different offscreen texture, and then we use that to for example clip a square image so that it looks circular. Due to a bug in the PowerVR driver, when we render the clip mask it was incorrectly being written to the texture cache, overwriting the item that was supposed to be in there. This is why you see strange red rounded-corner shapes on top of some of the images. This was due to a function called glInvalidateFramebuffer, which tells the driver when we are finished with a texture so that it can free the memory. It seems as if the driver was incorrectly freeing the memory too early, and therefore writing the mask to the wrong place.

I have made a fix to avoid calling this function on PowerVR GPUs. It should make its way to Firefox Nightly in the next few days, and hopefully in to a beta release soon as well. I'd be grateful if you could check in a few days whether this has been fixed. Thanks!

[jawadalkassim]

@jamienicol Sure, I'll test firefox nightly , and tell you when the issue is fixed

[jawadalkassim]

@jamienicol Finally Fixed 😍😍 thank you FF Nightly 93.0a1 (Build #2015827755)