[css-align] Baseline alignment of absolute positioned items

[javifernandez]

First of all, my understanding is that out-of-flow elements doen't participate in Baseline alignment. Is this assumption correct ? So far, neither Firefox, Safari or Chrome consider such elements as part of Baseline alignment, neither in Flexbox or Grid.

If the above assumption is correct, is there any spec that states something in that regard ? I found this statement in the grid spec:

https://drafts.csswg.org/css-grid/#static-position

An absolutely-positioned child of a grid container is out-of-flow and not a grid item, and so does not affect the placement of other items or the sizing of the grid.

However, I think the statement above was not intended to be applied to the Baseline Alignment logic, which indeed causes items to affect others in the Sharing Baseline Context. Should we add something specific to the Baseline values in the Alignment spec ? Perhaps here ?

https://drafts.csswg.org/css-align/#justify-abspos-static

[fantasai]

An absolutely-positioned item doesn't belong to any shared alignment context https://drafts.csswg.org/css-align/#shared-alignment-context so it can't participate in baseline alignment with anything else, though.