Bug 94855 – flex item sized incorrectly in a column flexbox with height set via top/bottom

• Status: RESOLVED
• Resolution: FIXED
• Component: CSS

[Steve Orvell]

Created attachment 160246 [details]
Reduction showing actual and expected output.

If a display: -webkit-flex element with flex-flow: column is itself sized by fitting to another container via: setting position absolute + top, bottom, right, left all to 0, then its flex items lose their flexibility and appear to have natural size. 

Note, this problem only occurs for column flex-flow, row is ok. Further, setting height: 100% is ok.

[Steve Orvell]

Created attachment 160251 [details]
corrected reduction

[Ojan Vafai]

Yup, looks like a bug. Not sure where exactly the bug is though.

[Tony Chang]

(In reply to comment #2)
> Yup, looks like a bug. Not sure where exactly the bug is though.

I think it's because we do our own calculation of height by calling computeLogicalClientHeight directly in RenderFlexibleBox::mainAxisContentExtent. It doesn't look like computeLogicalClientHeight handles absolute sized boxes.  If you look at computeLogicalHeight, it does:
    if (isOutOfFlowPositioned())
        computePositionedLogicalHeight();

Ok, I think I now know enough to fix this bug :)

[Tony Chang]

Sorry, it's going to take a while to fix this bug.  I need to fix bug 94982 first, and that's going to take a while.

[Tony Chang]

Created attachment 163723 [details]
Patch

[Ojan Vafai]

Comment on attachment 163723 [details]
Patch

Add a FIXME for mainAxisContentExtent to be used for all the places we call computeLogicalHeight(...)?

[Tony Chang]

Created attachment 163729 [details]
Patch for landing

[WebKit Review Bot]

Comment on attachment 163729 [details]
Patch for landing

Clearing flags on attachment: 163729

Committed r128383: <http://trac.webkit.org/changeset/128383>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.