1221865 - Text shadow should be painted below text in adjacent elements at the same stacking level

Status: NEW

(Core :: Layout: Text and Fonts, defect)

Description

[Xidorn Quan [:xidorn] UTC+10]

See the attachment. In this test, the green areas are two characters, and the red area is the text shadow of the second character. The text shadow is incorrectly painted above the first character.

The CSS Text Decoration Module Level 3 says:
> UAs should avoid painting text shadows over text in adjacent elements belonging to the same stack level and stacking context.
so it is just a recommendation, but I don't think we have any reason not to do that.

Our current implementation matches what CSS2 says. To update the impl to match Text Decoration Level 3, we may need to move text shadow into an independent display item, so that we can put it in a different stack level between text and border/background.

Comment 1

[Xidorn Quan [:xidorn] UTC+10]

Attachment: testcase