This one is puzzling to me. The attached test has two named flows, each with multicol layout, each flowing into different regions. The named flow elements have no width (or height) specified and neither do the regions. Result: The content does not render in the regions Expected: Should render Workaround: Specify a width on the named flow multicol element Additional Info: It's puzzling for a couple of reasons. First, this test passes in Canary and fails in Safari. Second, if I make the column-gap smaller - even just by 2px, the content renders.
Created attachment 210527 [details] test file for bug
Created attachment 210528 [details] reference file for test
Multi-column inside regions bug. The test seems to pass with the new-multicolumn implementation. Mark as fixed once a test is added.
CSS Regions were removed in Bug 174978.