1055888 - (flexbox-spec-changes) [META] Tracking bug for CSS flexbox spec changes

Status: NEW

(Core :: Layout, enhancement)

Description

[Daniel Holbert [:dholbert]]

I'm filing this bug to track changes that are (or have been in the past) needed to our CSS flexbox implementation, due to a spec change.

(I'm hoping this reduces the likelihood that an important spec change will get forgotten about and accidentally un-implemented.)

Comment 1

[Karl Dubost💡 :karlcow]

Search about 'flex-basis: auto' in Github
https://github.com/search?utf8=%E2%9C%93&q=%22flex-basis%3A+auto%22&type=Code&ref=searchresults

Comment 2

[Daniel Holbert [:dholbert]]

Thanks -- so, those are all candidates that *might* be (but aren't necessarily) broken by bug 1032922.

The reason they aren't *necessarily* broken is that "flex-basis:auto" and "flex-basis:main-size" may actually produce the same used value (of "auto"), if the main-size property's computed value is "auto". 

In particular, if an element has width:auto; height:auto (the initial values), then "flex-basis:main-size" and "flex-basis:auto" are essentially equivalent.  (Tab hinted at this in the last sentence of [1].)  And in fact, if the author's goal is really "start at the content's auto-width, and then flex from there", then flex-basis:auto is arguably the correct way to express that.  (And it's even more correct now that they can directly ask for "auto", instead of having to rely on flex-basis seeing "auto" and then looking over at width to discover "auto" there.)

So -- we can't necessarily say anything about the brokenness of the CSS in comment 1, without doing a bit more digging (to discover whether the elements have "width" or "height" set to something non-auto).  That sort of thing probably merits its own bug.

[1] http://lists.w3.org/Archives/Public/www-style/2014Jul/0008.htm

Comment 3

[Daniel Holbert [:dholbert]]

sorry, [1] was meant to be http://lists.w3.org/Archives/Public/www-style/2014Jul/0008.html
(I must've backspaced the final "l" accidentally)

Comment 4

[Daniel Holbert [:dholbert]]

Also: I've just filed bug 1057162 to cover website issues of the sort discussed in comment 1 - comment 3.  Any subsequent discussion on that topic should go over there.