Bug 240341

Summary:	Turn legacy properties that share a computed style into aliases or shorthands
Product:	WebKit	Reporter:	Oriol Brufau <obrufau>
Component:	CSS	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	ntim, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified
Bug Depends on:	104805, 166782, 197656, 239808, 243562
Bug Blocks:

Description Oriol Brufau 2022-05-12 06:23:22 PDT

Currently, there are 8 pairs of properties that share a computed style:

 * background-clip, -webkit-background-clip
 * background-origin, -webkit-background-origin
 * background-size, -webkit-background-size
 * box-shadow, -webkit-box-shadow
 * mask-clip, -webkit-mask-clip
 * mask-composite, -webkit-mask-composite
 * mask-mode, -webkit-mask-source-type
 * text-combine-upright, -webkit-text-combine

This is a non-standard hack. CSS Cascade defines 2 standard ways: https://www.w3.org/TR/css-cascade-5/#aliasing
 * legacy name aliases, for properties with the same exact syntax
 * legacy shorthands, for properties with different syntax

So the -webkit- properties above should be turned into aliases or shorthands.

The current hack is more likely to break things, e.g. revert-layer was broken before bug 238125, and CSSOM is still broken (bug 238874).

Comment 1 Tim Nguyen (:ntim) 2022-05-12 08:34:26 PDT

Bug 104805 is an example of legacy shorthand.

Comment 2 Radar WebKit Bug Importer 2022-05-19 06:24:13 PDT

<rdar://problem/93572921>