Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: 02cc0941250b2e56725a417c2a1bf8a7fc4e533e
https://github.com/WebKit/WebKit/commit/02cc0941250b2e56725a417c2a1bf8a7fc4e533e
Author: Ahmad Saleem <[email protected]>
Date: 2026-10-13 (Tue, 13 Oct 2026)
Changed paths:
A
LayoutTests/imported/w3c/web-platform-tests/css/css-values/typed-arithmetic-negated-product-expected.txt
A
LayoutTests/imported/w3c/web-platform-tests/css/css-values/typed-arithmetic-negated-product.html
M Source/WebCore/css/calc/CSSCalcTree+Simplification.cpp
Log Message:
-----------
calc() negation of a typed-arithmetic product flips the sign of every factor
https://bugs.webkit.org/show_bug.cgi?id=327205
rdar://189779826
Reviewed by Sam Weinig.
This patch aligns WebKit with Gecko / Firefox and Blink / Chromium.
When a Negate node's child is a Product whose children are all numeric,
simplify(Negate&) negated every child of the product. That is only
correct when the product has an odd number of factors, since
-(a * b) = (-a) * b, not (-a) * (-b). With typed arithmetic, a product
such as `2px * 3px` (type length^2) cannot be resolved on its own and so
survives simplification. Subtracting it then produced the wrong sign:
`calc((0px * 0px - 2px * 3px) / 1px)` resolved to 6px instead of -6px.
Negate only the first factor of the product instead.
Test:
imported/w3c/web-platform-tests/css/css-values/typed-arithmetic-negated-product.html
*
LayoutTests/imported/w3c/web-platform-tests/css/css-values/typed-arithmetic-negated-product-expected.txt:
Added.
*
LayoutTests/imported/w3c/web-platform-tests/css/css-values/typed-arithmetic-negated-product.html:
Added.
* Source/WebCore/css/calc/CSSCalcTree+Simplification.cpp:
(WebCore::CSSCalc::simplify):
Canonical link: https://commits.webkit.org/323577@main
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