Bug 213554

Summary: Child text-decoration-thickness and text-underline-offset override parent decorating boxes' values
Product: WebKit Reporter: Dominik Röttsches (drott) <d-r>
Component: TextAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: agafvv, kizmarh, mmaxfield, simon.fraser, webkit-bug-importer, zalan
Priority: P2 Keywords: InRadar
Version: Safari Technology Preview   
Hardware: Unspecified   
OS: Unspecified   
See Also: https://bugs.webkit.org/show_bug.cgi?id=203528
https://bugs.webkit.org/show_bug.cgi?id=230083
Attachments:
Description Flags
Offset nesting test
none
Thickness nesting test
none
Offset nesting actual
none
Offset nesting expected
none
Thickness nesting actual
none
Thickness nesting expected none

Description Dominik Röttsches (drott) 2020-06-24 05:44:55 PDT 
Created attachment 402640 [details]
Offset nesting test

In Safari release, and Safari TP, the current child node's text-decoration-thickness and text-underline-offset always override all previously defined text-decoration-thickness and text-underline-offset properties of parent elements / decorating boxes.

While working on Chromium's text-decoration-thickness and text-underline-offset, I noticed these discrepancies when writing a WPT test. 

Example test cases attached and available at:
http://roettsch.es/thickness-nesting.html
http://roettsch.es/offset-nesting.html

Actual: WebKit paints offset underlines and thickness-defined underline all at the same offset / thickness. 
Expected: Decorations should be stacked and the individual thickness and offset properties should be adhered too.
Comment 1 Dominik Röttsches (drott) 2020-06-24 05:45:11 PDT 
Created attachment 402642 [details]
Thickness nesting test
Comment 2 Dominik Röttsches (drott) 2020-06-24 05:47:13 PDT 
Created attachment 402643 [details]
Offset nesting actual
Comment 3 Dominik Röttsches (drott) 2020-06-24 05:47:30 PDT 
Created attachment 402644 [details]
Offset nesting expected
Comment 4 Dominik Röttsches (drott) 2020-06-24 05:47:44 PDT 
Created attachment 402645 [details]
Thickness nesting actual
Comment 5 Dominik Röttsches (drott) 2020-06-24 05:47:56 PDT 
Created attachment 402646 [details]
Thickness nesting expected
Comment 6 Dominik Röttsches (drott) 2020-06-24 05:48:52 PDT 
Potentially related to issue 203528.
Comment 7 Radar WebKit Bug Importer 2020-06-24 09:39:22 PDT 
<rdar://problem/64705955>