Bug 251753

Summary: Disconnected Arabic glyphs for embolden webfont
Product: WebKit Reporter: Ebrahim Byagowi <ebrahim>
Component: TextAssignee: Nobody <webkit-unassigned>
Status: NEW    
Severity: Normal CC: karlcow, mmaxfield, webkit-bug-importer, zalan
Priority: P2 Keywords: BrowserCompat, InRadar
Version: Safari Technology Preview   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Disconnected Arabic glyphs none

Ebrahim Byagowi
Reported 2023-02-05 00:17:58 PST
Created attachment 464847 [details] Disconnected Arabic glyphs Happens in both tip of tree WebKit (6c4c9810) and Safari 16.2 1. Open https://datehijri.com/ (or its archive here https://web.archive.org/web/20230121054820/https://datehijri.com/ ) 2. Pinch to zoom on the green colored text below Actual: It has disconnected Arabic glyphs. Expected: Like Firefox and Chrome, not disconnected Arabic glyphs
Attachments
Disconnected Arabic glyphs (399.58 KB, image/png)
2023-02-05 00:17 PST, Ebrahim Byagowi 		no flags
Details
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Ebrahim Byagowi
Comment 1 2023-02-05 13:22:53 PST
Guess this is rather a CoreText bug than WebKit
alan
Comment 2 2023-02-05 15:51:05 PST
I noticed that some of the text (e.g. لتاريخ الميلادي:) was split into multiple runs and we painted them individually. Sometimes (incorrect) mismatching rounding directions could manifest in such subpixel gaps. However, after force-merging them all (so that لتاريخ الميلادي comes out as one TextRun) I was still able to see those tiny gaps, so this very well be a CoreText bug as you said. Myles, what do you think?
Radar WebKit Bug Importer
Comment 3 2023-02-12 00:18:19 PST
<rdar://problem/105352894>
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