[css-overflow-3] Intrinsic sizing of elements with continue:discard

[frivoal]

The definition of the continue property (and therefore, of its line-clamp shorthand) says that the content after the first forced or unforced break is not taken into account when computing the block direction min-content, max-content, or automatic sizes.

I think that should be changed to only ignore the content after the first forced break for that purpose. Allowing the intrinsic (block) size to depend on where unforced breaks would happen, means the intrinsic (block) size would depend on actually performing layout, and that's an cycle I'd rather not have, since the layout itself may depend on the intrinsic size.

[css-meeting-bot]

The CSS Working Group just discussed overflow-3, and agreed to the following:

• RESOLVED: intrinsic sizing only affected by forced breaks

The full IRC log of that discussion

<eae> Topic: overflow-3
<astearns> github: https://github.com//issues/3214
<eae> florian: intrinsic sizing, currently the spec says that, in the block direction, is from the beginning of the content to the first forced or unforced break.
<eae> florian: That is problematic in that we don't know where the first unforced break is until layout
<eae> florian: Would suggest we change it to the first forced break. From start of content to first forced break.
<eae> dbaron: Two thoughts, one is that I hope the content that is after the first forced break contributors to the intrinsic size of something. Not sure what but should contribute to something.
<eae> florian: Only talking about the discard case now.
<eae> dbaron: For discard that seems reasonable, for some other cases min and max content would do different things. Min content would look at first break opportunity.
<fantasai> while max-content looks until first forced break
<eae> astearns: In cases where there is a fixed height then discard
<eae> florian: We should only conider forced breaks only for the purpose of intristic sizing, for other purposes the spec stays unchanged.
<eae> fantasai: I think this makes sense
<eae> RESOLVED: intrinsic sizing only affected by forced breaks
<fantasai> it would be problematic I think for the 2nd fragmentainer and beyond, but for the first fragmentainer it's doable and reasonable