NEW293471
Compositing layers clip font glyphs with large ascenders/descenders 
https://bugs.webkit.org/show_bug.cgi?id=293471
Summary Compositing layers clip font glyphs with large ascenders/descenders
Matt Moran
Reported 2025-05-22 20:23:25 PDT
Compositing layers clip font glyphs with large ascenders/descenders. Steps to reproduce: 1. Load the provided test case 2. Observe that the first "S" renders correctly 3. Observe that the second "S" (with opacity: 0.5) is clipped at top and bottom 4. Click or highlight the middle paragraph 5. Observe that the bottom of the first "S" disappears Some other styles (e.g. `will-change: transform`) with the custom font causes immediate clipping
Attachments
Test case (347 bytes, text/html)
2025-05-22 20:23 PDT, Matt Moran 		no flags
Details
Font with large ascenders & descenders (62.52 KB, font/woff)
2025-05-22 20:24 PDT, Matt Moran 		no flags
Details
Screenshot of Safari, clipped S at the bottom (38.34 KB, image/png)
2025-05-22 20:24 PDT, Matt Moran 		no flags
Details
Screenshot of Chrome (29.80 KB, image/png)
2025-05-22 20:24 PDT, Matt Moran 		no flags
Details
Screenshot of Firefox (38.53 KB, image/png)
2025-05-22 20:25 PDT, Matt Moran 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Matt Moran
Comment 1 2025-05-22 20:23:44 PDT
Created attachment 475346 [details] Test case
Matt Moran
Comment 2 2025-05-22 20:24:07 PDT
Created attachment 475347 [details] Font with large ascenders & descenders
Matt Moran
Comment 3 2025-05-22 20:24:37 PDT
Created attachment 475348 [details] Screenshot of Safari, clipped S at the bottom
Matt Moran
Comment 4 2025-05-22 20:24:57 PDT
Created attachment 475349 [details] Screenshot of Chrome
Matt Moran
Comment 5 2025-05-22 20:25:08 PDT
Created attachment 475350 [details] Screenshot of Firefox
Radar WebKit Bug Importer
Comment 6 2025-05-29 20:24:23 PDT
<rdar://problem/152289503>
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