1893855 - different and wrong calculated width in new version

Status: RESOLVED DUPLICATE of bug 1893127

(Core :: Layout, defect)

Description

[farzad]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36

Steps to reproduce:

Update the firefox from v124.0.2 to v125.0.2

Actual results:

It seems there is a change in float calculation and this cause final result to be different. Consider a div parent with 1183.3333740234375px width and three flex children each with calc(33.3333% - 10px) width. The actual calculated width in two versions are different. The widthes in new version are bigger and this cause responsiveness problems in my website.

Expected results:

Calculated widths should be the same as previous versions. There is an attached file. Execute it and see with diffs in v124.0.2 and v125.0.2

Comment 1

[farzad]

Attachment: sample.html

Comment 3

[Robert Longson [:longsonr]]

It would be helpful if you could determine a regression range with mozregression

Comment 4

[farzad]

(In reply to Robert Longson [:longsonr] from comment #3)

It would be helpful if you could determine a regression range with mozregression

Hi
sorry for the delay of my response

I tried a few times to get final report however the software froze at final step. I send an image of gui and hope It will be helpful

Comment 5

[farzad]

Attachment: mozilla regression.PNG

Comment 6

[farzad]

Here is a new version of Sample.html file. This file show the problem clearly. Divs in correct output should not wrap and they should be in the same line

Comment 7

[farzad]

Attachment: sample.html

v2 with flex wrap

Comment 8

[Ardelean Oana, Desktop Test Engineering [:oardelean]]

Hello, thank you for the bug report!
I ran a regression range and found the same range as shown in the reporter’s attached image.

Results:

• last good: 2024-02-27
• first bad: 2024-02-28
• pushlog: https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=f0fd4d27a58991220e91d1c086442a03b0a52117&tochange=09a1b473f8dab1609e2ca9ae45ead6a8300d9a78

However, I could not reproduce this issue on Firefox Nightly 128.0a1, Firefox 127.0b4 and Firefox 126.0 using the attachment from Comment 7.
I ran mozregression to find a potential fix.

Results:

• last bad: 2024-04-27
• first good: 2024-04-28
• pushlog: https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=fddecabd2a42707349d6019b5d0b1f10d8e46217&tochange=8256dde0533523666a60914881f81717e1705f8a

Reporter, could you please confirm if the issue is still reproducible on the latest nightly and beta builds respectively?

Moving the Product to ‘Core’ and Component to ‘Layout’. Please change if there’s a better fit, thank you.

Comment 9

[farzad]

Hi
It seems the bug has been fixed.
Thank you