[css-sizing][css-multicol][css-grid-1] taking into account gaps/gutters in Intrinsic Sizes in Multi-column and Grid Layout

[frivoal]

https://drafts.csswg.org/css-sizing/#multicol-min-content says:

The min-content inline size of a multi-column element with a computed column-width of auto is the largest min-content inline-size contribution of its contents multiplied by its column-count (treating auto as 1).

Is that right? How about column-gap? Doesn't this make more sense?

The min-content inline size of a multi-column element with a computed column-width of auto is the largest min-content inline-size contribution of its contents multiplied by its column-count (treating auto as 1), plus the column-gap multiplied by column-count minus 1.

Similarly, I think

The min-content inline size of a multi-column element with a computed column-width not auto is the smaller of its column-width and the largest min-content inline-size contribution of its contents.

should be

The min-content inline size of a multi-column element with a computed column-width not auto is the smaller of its column-width and the largest min-content inline-size contribution of its contents, multiplied by by its column-count (treating auto as 1), plus the column-gap multiplied by column-count minus 1.

[frivoal]

Actually, it's the same issue in https://drafts.csswg.org/css-sizing/#multicol-max-content and https://drafts.csswg.org/css-sizing/#multicol-max-content-restrained
everytime you multiply something by the column-count, you need to add the column-gap multiplied by column-count minus 1.

[frivoal]

Similarly, I think

The min-content inline size of a multi-column element with a computed column-width not auto is the smaller of its column-width and the largest min-content inline-size contribution of its contents.

should be

The min-content inline size of a multi-column element with a computed column-width not auto is the smaller of its column-width and the largest min-content inline-size contribution of its contents, multiplied by by its column-count (treating auto as 1), plus the column-gap multiplied by column-count minus 1.

Actually, scrap that, this part is wrong. The rest still stands.

[mrego]

I think we've a similar issue on the Grid Layout spec:

The max-content size of a grid container is the sum of the grid container’s track sizes in the appropriate axis, when the grid is sized under a max-content constraint.

The min-content size of a grid container is the sum of the grid container’s track sizes in the appropriate axis, when the grid is sized under a min-content constraint.

I guess we should include the gutters here too.

[tabatkins]

Yeah, we're missing gaps/gutters in those.

[tabatkins]

Okay, so Multicol is done now, and Grid specifically defines that gutters are treated as tracks for the purposes of sizing, so we don't actually need to call out gutters specifically there.