Bug 218630 – [css-grid] IndefiniteSizeStrategy::findUsedFlexFraction can iterate the same item multiple times

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

[Oriol Brufau]

IndefiniteSizeStrategy::findUsedFlexFraction needs to iterate all grid items that cross a flexible track. To do so it, takes the indices of the flex tracks, and for each one it uses GridIterator to iterate the items in that track.

Then, to avoid processing the same item multiple times, it checks that the item started in the current flex track, not in a previous one.

However, this is insufficient: it's not taking into account that an item can be in a single flex track, but span multiple tracks in the other axis.

This can make it very slow. Testcase: https://jsbin.com/hefajukaxo/1/edit?html,css,js,output

Chromium has been fixed in https://crbug.com/1026275

[Oriol Brufau]

Created attachment 413335 [details]
Patch

[Javier Fernandez]

Comment on attachment 413335 [details]
Patch

r=me

[EWS]

Committed r269509: <https://trac.webkit.org/changeset/269509>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 413335 [details].

[Radar WebKit Bug Importer]

<rdar://problem/71117312>