[css-flexbox][css-sizing] Move min-width and min-height partial definitions to css-sizing

[Loirooriol]

CSS Flexbox provides partial definitions of min-height and min-width with the new auto initial value.

This kind of things should not be allowed. How is someone looking for the initial value of these properties supposed to know that it's defined in Flexbox?

So I think these definitions should be moved to wherever makes sense. Probably this would be css-box, but it seems it has been abandoned. So css-sizing seems the best option.

Then css-sizing would define auto as the initial value, and say that it represents the "automatic minimum size" which, unless otherwise defined by the layout model, is 0. CSS Flexbox and CSS Grid should only define this automatic minimum size in their layouts.

[fantasai]

Makes sense to me. Agenda+ to get WG approval.

[css-meeting-bot]

The Working Group just discussed Sizing - moving min-width/height partial dfns to Sizing, and agreed to the following resolutions:

• RESOLVED: Move definition of the min-width:auto keyword to Sizing.

The full IRC log of that discussion

<TabAtkins> Topic: Sizing - moving min-width/height partial dfns to Sizing
<astearns> github: https://github.com//issues/1920
<TabAtkins> fantasai: Oriol pointed out the Flexbox isn't the best place to define a new initial value for min-widht/height.
<TabAtkins> fantasai: Suggested it move to the Sizing spec. Makes sense to me.
<TabAtkins> fantasai: Definition of what automatic size means in Flexbox wills tay, but move the propdef that defines the keyword to Sizing.
<TabAtkins> Rossen: Sounds reasonable.
<TabAtkins> RESOLVED: Move definition of the min-width:auto keyword to Sizing.