Bug 311833

Summary:

height: 100% changes layout when the parent height is defined via aspect-ratio

Product:

WebKit

Reporter:

michael

Component:

Layout and Rendering

Assignee:

alan <zalan>

Status:

RESOLVED FIXED

Severity:

Major

CC:

bfulgham, sgill26, simon.fraser, webkit-bug-importer, zalan

Priority:

Keywords:

InRadar

Version:

Safari 26

Hardware:

Mac (Apple Silicon)

OS:

macOS 26

See Also:

https://github.com/web-platform-tests/wpt/pull/59424

Attachments:

Description	Flags
Test reduction	none
Patch	none
Patch	none
[fast-cq]Patch	none

michael

Reported 2026-04-09 10:31:24 PDT

Consider this markup: ```html <div style="width: 500px; aspect-ratio: 7882 / 5257;"> <div style="height: 100%"></div> </div> ``` In Safari (both on desktop and mobile), the inner div with `height: 100%` leads to a few extra pixels added to the height of the inner and outer div. I suspect some wrong height calculation in the layout engine. See repro: https://cdn.letsken.com/repros/001-safari-height-100-percent.html

Attachments
Test reduction (420 bytes, text/html) 2026-04-09 11:13 PDT, alan	no flags	Details
Patch (6.02 KB, patch) 2026-04-09 11:55 PDT, alan	no flags	Details Formatted Diff Diff
Patch (5.78 KB, patch) 2026-04-09 12:00 PDT, alan	no flags	Details Formatted Diff Diff
[fast-cq]Patch (5.77 KB, patch) 2026-04-09 13:21 PDT, alan	no flags	Details Formatted Diff Diff
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