Created attachment 112614 [details]
Specifically, it doesn't scroll.
This seems to work for me now. I bet adding the layout in the stretch case fixed it. I'll add some tests for it.
Created attachment 122133 [details]
Comment on attachment 122133 [details]
Clearing flags on attachment: 122133
Committed r104785: <http://trac.webkit.org/changeset/104785>
All reviewed patches have been landed. Closing bug.
Hmm, turns out that we get the wrong behavior when we're not using flex-item-align: stretch. I'll debug some more.
(In reply to comment #5)
> Hmm, turns out that we get the wrong behavior when we're not using flex-item-align: stretch. I'll debug some more.
Nevermind, it's working properly. The cross direction was auto on the div that have 'overflow: auto' so there was no overflow in the cross direction (in the case of stretch, we would shrink to match the flexbox size and scrollbars would appear).