Bug 259702

Summary:	[CSS Math Functions] round() is incorrect when number is a multiple of step
Product:	WebKit	Reporter:	Natalie Weizenbaum <nweiz>
Component:	CSS	Assignee:	Tim Nguyen (:ntim) <ntim>
Status:	RESOLVED FIXED
Severity:	Normal	CC:	janeori, ntim, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	Safari 16
Hardware:	Mac (Apple Silicon)
OS:	macOS 13
See Also:	https://github.com/web-platform-tests/wpt/pull/41284

Description Natalie Weizenbaum 2023-08-01 13:21:30 PDT

According to CSS Values and Units 4 (https://drafts.csswg.org/css-values-4/#round-func), for any round() strategy,

> If A is exactly equal to an integer multiple of B, round() resolves to A exactly

However, round(up, 10px, 5px) resolves to 15px instead of 10px as it should.

Tested in Safari 16.6.

Comment 1 Radar WebKit Bug Importer 2023-08-01 16:10:04 PDT

<rdar://problem/113233588>

Comment 2 Tim Nguyen (:ntim) 2023-08-01 18:49:24 PDT

Pull request: https://github.com/WebKit/WebKit/pull/16302

Comment 3 Tim Nguyen (:ntim) 2023-08-01 18:57:22 PDT

Submitted web-platform-tests pull request: https://github.com/web-platform-tests/wpt/pull/41284

Comment 4 EWS 2023-08-01 21:05:05 PDT

Committed 266504@main (58d1ff825f4e): <https://commits.webkit.org/266504@main>

Reviewed commits have been landed. Closing PR #16302 and removing active labels.

Comment 5 Tim Nguyen (:ntim) 2023-10-14 07:57:36 PDT

*** Bug 263145 has been marked as a duplicate of this bug. ***