[css-multicol] the minimum and preferred width of a multicol is not defined anywhere

[FremyCompany]

And, of course, that means it isn't interoperable ;-)
So even if it is defined somewhere implementers didn't find it...

https://drafts.csswg.org/css-multicol-1/#pseudo-algorithm

I think Firefox makes sense when you need fit-content:

https://jsfiddle.net/L03rqecj/2/

• Edge allocates 10 columns, then fill only three of them
• Firefox allocates as many columns as the container width allows, then fill only three of them
• Chrome allocates as many columns as the container width allows, then fill only two of them by wrapping the first two lines on the same column, but not the third one (wait, what)?

And it makes sense again when you need min-content:

https://jsfiddle.net/L03rqecj/3/

• Edge does as it does in the previous case (whaaaat?)
• Firefox collapses the whole thing to one column (of about 10px size)
• Chrome does like it did for preferred width (whaaaat?)

I have seen real interop issues due to this while digging some tables bugs.

We should sort this out ;-)

[FremyCompany]

Cc @frivoal, and because chrome is buggy also @tabatkins

[mstensho]

Regarding Chrome's behavior in the first jsfiddle: This is because Chrome respects orphans and widows, whose initial values are 2. See https://bugs.chromium.org/p/chromium/issues/detail?id=638530

[fantasai]

Multi-col intrinsic sizes are defined in https://drafts.csswg.org/css-sizing-4/#multicol-intrinsic

[tabatkins]

Yup, looks like this is well-defined now (and results in Firefox's behavior).

• min-content size is the larger of its column-width and the largest width of its inline content; in this case, that is 100px.
• fit-content is just the normal algorithm: max-content size (here 10 * 100px) clamped by min-content size (100px) and available space. The multicol filling algorithm then decides how many columns to put into that area (here floor(screen-width / 100px, 100px), probably 4 or 5)

[frivoal]

Alright, since we have a definition everybody seems to be happy about, I'm closing this.

[frivoal]

@FremyCompany Based on you being there during the conf call where we decided on this, I'm labeling you as "Commenter Satisfied". Let me know if that is a misunderstanding.

[FremyCompany]

@frivoal No misunderstanding, I'm satisfied with the resolution 💯