Bug 267846 – (REGRESSION 262652@main): box-decoration-break: clone is not taken into account when breaking lines

• Status: ASSIGNED
• Component: Layout and Rendering

[Johannes Odland]

Created attachment 469494 [details]
A screenshot of the issue in iOS 17 simulator

The issue with box-decoration-break reported and fixed in https://bugs.webkit.org/show_bug.cgi?id=223687 seems to have returned.

Steps to reproduce the problem:
1. Add a span inside a div.
2. Define a width on the div.
3. Set `box-decoration-break: clone`, `padding: 15px` and `word-break: break-all` on the span.
4. Fill the span with text.

https://johannesodland.github.io/browserbugs/safari-box-decoration-break-clone-padding-ignored-issue.html

What is the expected behavior?
The padding added on each line through `box-decoration-break: clone` should be accounted for when breaking lines. Each padding-box should stay within the container. 

What went wrong?
The extra padding is not accounted for when breaking lines and the extra padding overflows the container.

Did this work before? 
Yes, it worked in Safari 16.4

Does this work in other browsers? 
Yes, it works in Firefox

[Radar WebKit Bug Importer]

<rdar://problem/121382658>

[zalan]

(In reply to Johannes Odland from comment #0)
> Created attachment 469494 [details]
> A screenshot of the issue in iOS 17 simulator
> 
> The issue with box-decoration-break reported and fixed in
> https://bugs.webkit.org/show_bug.cgi?id=223687 seems to have returned.
oh noo! Let me figure out what happened here.
(and thank you for filing it!)

[zalan]

This has regressed at 262652@main. It looks like we did not have proper regression test coverage on this (now we do!).

[zalan]

fixing it now.