1233218 - [css-grid] Grid row track sizing does not keep up with descendant size changes

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Eric A. Meyer]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:46.0) Gecko/20100101 Firefox/46.0
Build ID: 20151216030229

Steps to reproduce:

I created a testcase where images’ sizing was either a percentage of the grid item they inhabit, or a fixed width: http://meyerweb.com/eric/css/tests/grid-resizing.html

(Note the credit in that testcase for where it came from, and follow it to see another example of grid sizing problems, this time with `width`.  I did not file a separate bug because I don’t know if the problems are the same problem, or related problems.)


Actual results:

In the first two tests, the grid row tracks are erroneously sized as if the images had not been scaled to fit their parent elements (which are grid items; the images themselves are not).  Interestingly, this scales with percentage values, so a `width: 50%` will create grid row tracks half as tall as those where the images are given `width: 100%`.

In the third test, where the images are given explicit pixel widths, the error does not happen.


Expected results:

The grid row tracks should be sized to fit the content as it is displayed, and resized if the content resized.  This does happen if you check the checkbox before the second test (the `width: 50%` test): the grid row tracks are made large enough to fit the suddenly huge pictures.  Unchecked the box, though, and the grid row tracks go back to their previous, erroneous size.

Note: this bug may or may not be related to https://bugzilla.mozilla.org/show_bug.cgi?id=1222724.

Comment 1

[Daniel Holbert [:dholbert]]

Mats, mind taking a look?

Comment 2

[Mats Palmgren (inactive)]

Yeah, I'll get to this in the next few weeks hopefully.

Comment 3

[Mats Palmgren (inactive)]

This should be fixed by bug 1174569 in the latest Nightly.

Comment 4

[Mats Palmgren (inactive)]

Actually, the fix is only on m-c, it will be in the *next* Nightly we build from there...
(so it will take a day or so)