Bug 251009

Summary:	InlineTextBoxes containing Zero Width Joiner, Zero Width Non-Joiner , or Zero Width No-Break Space must not use simplified text measuring
Product:	WebKit	Reporter:	Vitaly Dyackhov <vitaly>
Component:	Text	Assignee:	Nobody <webkit-unassigned>
Status:	RESOLVED FIXED
Severity:	Normal	CC:	mmaxfield, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified

Description Vitaly Dyackhov 2023-01-23 06:38:57 PST

When calculating the width of an InlineTexBox using simplified measuring, we simply sum up the width of every glyph. Some fonts (at least FreeType fonts) specify the non-zero width of `Zero Width Joiner`, `Zero Width Non-Joiner`, and `Zero Width No-Break Space`. Later, during the rendering, these glyphs are skipped causing the `InlineTextBox`es to become wider than they should be.

Comment 1 Vitaly Dyackhov 2023-01-23 06:46:58 PST

Pull request: https://github.com/WebKit/WebKit/pull/8973

Comment 2 Radar WebKit Bug Importer 2023-01-30 06:39:16 PST

<rdar://problem/104819130>

Comment 3 EWS 2023-01-31 01:53:20 PST

Committed 259618@main (f7b4df2d3a2c): <https://commits.webkit.org/259618@main>

Reviewed commits have been landed. Closing PR #8973 and removing active labels.