[css-inline-3] baseline-source:first and overflow:hidden inline-boxes.

[bfgeek]

https://drafts.csswg.org/css-inline-3/#baseline-source

The definition of this property doesn't mention the overflow:hidden behaviour explicitly - that is we'll force baselines on scrollers (overflow:hidden and friends) to the block-end margin edge by default.

For the non-auto cases (baseline-source:first and baseline-source:last) we can likely allow people to have the same behaviour as baselines within scrollers for flex/grid, that is clamp the baselines to the border-box rect if present.

For example:

baseline <div style="display: inline-block; overflow: hidden; baseline-source: first;">I am aligned</div>

Ian

[css-meeting-bot]

The CSS Working Group just discussed [css-inline-3] baseline-source:first and overflow:hidden inline-boxes., and agreed to the following:

• RESOLVED: Accept this behavior for baseline-source:first|last

The full IRC log of that discussion

<dael> iank_: baseline-source longhand has 2 values which is what we do already. It will behave css2 baseline. We also have baseline-source:first and last
<TabAtkins> gonna go ahead and +1 Ian's suggestion for this issue, it sounds good
<Rossen_> q?
<dael> iank_: The definition...currently the thing that conflicts si when you have overflow:hidden specified. We'll snap to end margin edge. A lot of webdev dislike this behavior. If you add overflow:hidden to hide visual effects you lose baseline alignment. For baseline-source:first|last it would be good to skip that behavior and use clamping like flexbox and gir
<dael> s/gid/grid
<dael> s/gir/grid
<dael> TabAtkins: Sounds great, I like it
<dael> iank_: fwiw the baseline-source:auto needs to be tightened up a little bit to capture some nuance
<dael> Rossen_: Objections?
<dael> RESOLVED: Accept this behavior for baseline-source:first|last