Affected versions

• Firefox 68.0a1
• Firefox 67.0b7
• Firefox 66.0.2

Affected platforms

• macOS 10.14
• Windows 10 x64
• Ubuntu 18.04 x64

Steps to reproduce

1. Go to https://testdrive-archive.azurewebsites.net/Performance/FishBowl/
2. From the list on the left side uncheck the option for "Frame" (and for "Mask" - Ubuntu and Windows)

Expected result

• The frame of the bowl disappears and there is no white square between the bowl and the background.

Actual result

• There is a white square appear between the bowl and the background

Regression range

• This might not be a regression, I can reproduce the issue on Nightly from 2017-01-02. I will try to find more information as soon as possible.

Additional notes

• Please look at the attached png.

(In reply to Oana Botisan, Desktop Release QA from comment #0)

Expected result

• The frame of the bowl disappears and there is no white square between the bowl and the background.

Why do you think this is the expected result? The white square appears in Chrome and with WebRender off.

(I tested on macOS, just unchecking the "Frame")

It looks like the image is broken. I actually thought that it looks like a glitch. I am not sure how the layers are made on the site, but I am not sure that it should be a white square there until you uncheck the "Mask" option. Maybe it's just a site related issue.

I don't this is a regression. I can reproduce the issue on builds from 2010-01-02 and before that I can't seem to make the site load on Firefox.
But like I said in comment 3, this might be just a site related issue.

This isn't a bug. That's just how the site is built.