Re: [csswg-drafts] [css-align][css-sizing] Indefinite percentages in calc() are underspecified

The Working Group just discussed `calc() with percentages in margins/padding`, and agreed to the following resolutions:

* `RESOLVED: zero out percentages on non-sizing use of calc`

<details><summary>The full IRC log of that discussion</summary>
&lt;fantasai> Topic: calc() with percentages in margins/padding<br>
&lt;dael> github: https://github.com/w3c/csswg-drafts/issues/2297#issuecomment-376263348<br>
&lt;fantasai> github: https://github.com/w3c/csswg-drafts/issues/2297#issuecomment-376263348<br>
&lt;fantasai> rego: no<br>
&lt;rego> fantasai: :)<br>
&lt;dael> fantasai: it was to discuss 0ing out a % vs the entire expression. Example calc (10% + 10px) 0ing the entire expression is what's impl. 0ing the % is more meaningful. This is for purpose of calc intrinsic size calc of element.<br>
&lt;dael> dbaron: It's also continuous in terms of what happens when you have a calc that approaches 0 and you remove the calc.<br>
&lt;fantasai> Comment summarizing issue: https://github.com/w3c/csswg-drafts/issues/2297#issuecomment-376263348<br>
&lt;dael> TabAtkins: Are we okay with some properties having a different indefinite percent with calcs.<br>
&lt;dael> fantasai: I prefer 0 out the %<br>
&lt;dael> florian: Justification to 0 everything other then it's what we have<br>
&lt;dael> fantasai: Id din't hear anything.<br>
&lt;dael> Rossen: I agree with fantasai. 0ing the % makes more sense. Having a box model with tabbing and you'll 0 out %<br>
&lt;dael> fantasai: For size we ignore entire calc. We closed that in #1132. SOrry,w e throw out the calc and treat as auto. Fallback to initial value<br>
&lt;dael> fantasai: That makes snese for sizing in a way it doesn't here is if you fallback to the original that has some kind of meaning. In this case there's no meaningful value for margins and padding.<br>
&lt;dael> astearns: In only 0 out % for calc that's not sizing it's a slight descrepency.<br>
&lt;dael> fantasai: correct.<br>
&lt;dael> florian: We can do calc of 10%+10px is the same as 10px but we cant do auto+10px because that's not defined.<br>
&lt;Rossen> s/Having a box model with tabbing and you'll 0 out %/Having a box model with some % and non-% values results in the same logic, where we would zero out the % values and add the rest of the defined sizes/<br>
&lt;dael> astearns: Arguments against only 0ing out % on non-sizing use of calc<br>
&lt;dael> astearns: Obj?<br>
&lt;fantasai> (Florian was responding to Alan's question of why we throw out the expression for sizing props)<br>
&lt;dael> RESOLVED: zero out percentages on non-sizing use of calc<br>
</details>


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Received on Tuesday, 10 April 2018 13:07:17 UTC