1415759 - List markers should inherit 'line-height' from block

Status: NEW

(Core :: Layout: Block and Inline, enhancement, P3)

Description

[fantasai]

Firefox seems to set the line-height of a list marker to normal even if the list-item has line-height set to something else (like 1). This can cause the list-item to inflate the height of the line, which is quite unexpected.

Comment 1

[Sam Sneddon [:gsnedders]]

Attachment: TC.html

Comment 2

[Sam Sneddon [:gsnedders]]

Attachment: NotoNaskhArabic-Regular.subset.ttf

This and TC.html quite clearly show the issue, especially looking compared with Chrome.

Comment 3

[Sam Sneddon [:gsnedders]]

Attachment: TC.html

Comment 4

[Sam Sneddon [:gsnedders]]

I'm unconvinced it's actually `normal`. I think it's using the computed line height + 1 (in some unit I'm not entirely sure about). I'm seeing it always 1px out at 96dpi, regardless of font-size, and 0.5px out at 192dpi.

Comment 5

[Xidorn Quan [:xidorn] UTC+10]

It's... some kind of normal: https://searchfox.org/mozilla-central/rev/fb5422ff98ba43f3732debd9d1f4dcd3b3a920f6/layout/generic/nsBulletFrame.cpp#1113-1120

It uses the font's max height as its height, which should match how height is calculated for inline elements. The probably is probably that line layout / block frame shouldn't count height of bullet frame when placing lines.

(With that being said, IIRC I tried to make bullet frame match inline frame's behavior on line height, but that broke stuff... I cannot recall exactly what did I try to do and what was broken at that time, though.)