Bug 259424

Summary: [IFC] Modern LineLayout should respect subtreePaintRoot
Product: WebKit Reporter: Ethan Wong <bunnnywong>
Component: Layout and RenderingAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: bfulgham, simon.fraser, webkit-bug-importer, zalan
Priority: P2 Keywords: InRadar
Version: Safari 16   
Hardware: All   
OS: macOS 13   
Attachments:
Description Flags
text recognition results causing incorrect drag preview images
none
a more generic test case for this issue none

Description Ethan Wong 2023-07-23 00:02:45 PDT 
Created attachment 467090 [details]
text recognition results causing incorrect drag preview images

Possibly related bugs:
* https://bugs.webkit.org/show_bug.cgi?id=227630
* https://bugs.webkit.org/show_bug.cgi?id=237446

The modern path of RenderBlockFlow::paintInlineChildren should respect subtreePaintRoot.

As demonstrated by the attached screen recording, one of the specific behaviors caused by this issue is that text recognition results causing incorrect drag preview images for elements with draggable="true". It happens due to the results are rendered as large text and then shrinked down by transforms.
Comment 1 Ethan Wong 2023-07-23 00:03:42 PDT 
Created attachment 467091 [details]
a more generic test case for this issue
Comment 2 Ethan Wong 2023-07-23 00:04:54 PDT 
Pull request: https://github.com/WebKit/WebKit/pull/16019
Comment 3 Radar WebKit Bug Importer 2023-07-30 00:03:16 PDT 
<rdar://problem/113095239>