1769799 - Abspos Block with `writing-mode: vertical-lr` Inside `writing-mode: sideways-lr` Absolute Containing Block Incorrectly Positioned

Status: NEW

(Core :: Layout, defect)

Description

[David Shin[:dshin]]

Attachment: Minimum reproducible test case

STR:

• Load attached min reproducible case

Expected:

• The innermost div positioned as if its position: absolute property is not set

Actual:

• Toggling position: absolute via devtools moves the div

Found while investigating bug 1765668, but this behaviour happens regardless of the absolute containing block having a border.

parent and cb divs' writing modes can be switched with the identical behaviour. Does not seem to happen with any other combination of writing modes.

Comment 1

[Jonathan Kew [:jfkthame]]

Yeah, this seems wrong (though it's a pretty obscure combination!) Marking as S4 as it seems unlikely any real content will be using this, but we should still fix whatever is getting confused here.