1867056 - Solid-color background of elements with border-radius > 0px and on-screen width or height > 256px not drawn correctly on Windows ARM64

Status: RESOLVED DUPLICATE of bug 1852440

(Core :: Graphics, defect)

Description

[Jonas M [:jonasm]]

Attachment: Screenshot of an example HTML file comparing element sizes and styles.

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:121.0) Gecko/20100101 Firefox/121.0

Steps to reproduce:

Device: Microsoft Surface Pro X SQ1
Operating system: Microsoft Windows 11 Home (version 23H2, build 22631.2715)
Firefox: 121.0b4 (both ARM64 and 64-bit version exhibit this issue)
Steps to reproduce: Open any web page containing an element which has a border-radius > 0px, a visible solid color background, and is displayed with a width or height exceeding 256 pixels on-screen (after CSS transform, zoom-level and high-res screen scaling).

Actual results:

The element's solid-color background is not clipped to the rounded corners and is not drawn with the correct transparency (set by CSS opacity or background alpha value). Transparency caused by setting the element's CSS opacity < 1 gets applied correctly as long as the element has some other visible part (e.g. children, border) being drawn. Image and gradient backgrounds get clipped correctly.

Expected results:

Transparency and rounded corners should always be drawn correctly. More specifically, in the attached screenshot the rows with "width: 256px" and "width: 257px" should look identical except for the 1px width difference for each element.

Comment 1

[Jonas M [:jonasm]]

Attachment: Example HTML file shown in the initial screenshot

```html

Comment 2

[Jonas M [:jonasm]]

Attachment: Example HTML file shown in the screenshot

Comment 3

[Mayank Bansal]

Jonas, can you please attach the contents of about:support as an attachment on this bug?

Comment 4

[Timothy Nikkel (:tnikkel)]

Was this working in the past and just stopped working for you?

Comment 5

[Jonas M [:jonasm]]

Attachment: about:support

Comment 6

[Jonas M [:jonasm]]

(In reply to Timothy Nikkel (:tnikkel) from comment #4)

Was this working in the past and just stopped working for you?

When I first installed Firefox on this device in June 2023, that was probably version 114 and the issue appeared then and in every subsequent version since. However, I am working on regression testing right now and I was able to confirm that version 67 (the first one with an ARM64 build) does not exhibit the issue. I will try to narrow it down further.

Comment 7

[Jonas M [:jonasm]]

(In reply to Jonas M [:jonasm] from comment #6)

(In reply to Timothy Nikkel (:tnikkel) from comment #4)

Was this working in the past and just stopped working for you?

When I first installed Firefox on this device in June 2023, that was probably version 114 and the issue appeared then and in every subsequent version since. However, I am working on regression testing right now and I was able to confirm that version 67 (the first one with an ARM64 build) does not exhibit the issue. I will try to narrow it down further.

I must have remembered it wrong, since now I found out the regression was introduced between versions 115 and 116.

Comment 8

[Timothy Nikkel (:tnikkel)]

Thanks for the further info. You can use https://mozilla.github.io/mozregression/ to make the testing easier.

Comment 9

[Jonas M [:jonasm]]

(In reply to Timothy Nikkel (:tnikkel) from comment #8)

Thanks for the further info. You can use https://mozilla.github.io/mozregression/ to make the testing easier.

Thanks, this is a really helpful tool! I was able to pin down the responsible commit: https://hg.mozilla.org/integration/autoland/rev/928b0d1a27d51da8561d2e52e32fe6aa1354d7cb

Comment 10

[Mayank Bansal]

Thanks for the regression range!

Comment 11

[BugBot [:suhaib / :marco/ :calixte]]

:gw, since you are the author of the regressor, bug 1830588, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 12

[Jonas M [:jonasm]]

Just noticed this is probably a duplicate of Bug 1852440 which I did not find before. Should I add my additional info there and close this report?

Comment 13

[Glenn Watson [:gw]]

I'll mark this as a duplicate, which will close this but link it to the other bug.