The commit #30940 doesn't really fix the issue when you have more than one row. You can add flex-wrap to the flex container to make the rows behave correctly but then it breaks tho option to set one of the rows as

flex: 1 1 auto;

to make one of the rows take all of the unused space
Example

You can overcome the issue stated in commit #30940 by just adding flex-column to the flex container without having to break more things down the line.
Example