Re: [css-grid] Containing block for abs.pos. grid items when the grid overflows

On Wed, Mar 25, 2015 at 7:49 AM, Mats Palmgren <mats@mozilla.com> wrote:
> Can someone clarify how to calculate the containing block (CB)
> for an abs.pos. grid item that has "grid-column: 2 / auto"
> when line 2 is outside padding-area (on the right side)?
> I can't find anything in the Grid spec that defines this case.
> (example included below)

The behavior falls out of the placement definitions.  The abspos has
one line for its placement - its column-start is 2.  Its default span
is 1, per spec, so its column-end gets computed to 3.

Since the abspos doesn't actually contribute to layout, lines 2 and 3
end up coincident (in your example), so the containing block is indeed
zero width.

~TJ