csswg-drafts (original) (raw)

When exactly does 'auto' compute to zero?

http://software.hixie.ch/utilities/js/live-dom-viewer/?%3C!DOCTYPE%20html%3E%0A%3Cstyle%3E%0A%20%20html%20%7B%20display%3A%20flex%3B%20%7D%0A%3C%2Fstyle%3E%0ATest%0A%3Cscript%3E%0A%20%20w(window.getComputedStyle(document.body%2C%20null).getPropertyValue(%27min-height%27))%3B%0A%3C%2Fscript%3E

The wording in Flexbox https://www.w3.org/TR/css-flexbox-1/#min-size-auto isn't particularly clear.

On a flex item whose overflow is visible in the main axis, when specified on the flex item’s main-axis min-size property, specifies an automatic minimum size. It otherwise computes to 0 (unless otherwise defined by a future specification).

Does it compute to zero

on flex items, in the main axis, when 'overflow' is visible?
on flex items, in the main axis, always? (Firefox does this)
on flex items, in both axes? (Chrome does this)

We should probably bias towards computing to auto in as many cases as is Web-compatible, but we should also fix the spec to say exactly what happens.