<!DOCTYPE html> <meta charset="utf-8"> <link rel="author" title="Daniel Holbert" href="mailto:dholbert@mozilla.com"> <link rel="author" title="Ting-Yu Lin" href="mailto:tlin@mozilla.com"> <link rel="author" title="Mozilla" href="https://www.mozilla.org/"> <link rel="help" href="https://drafts.csswg.org/css-break/#break-decoration"> <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1693616"> <meta name="assert" content="This test verifies that a block element with box-decoration-break:clone, whose block-start border and padding exceed the multicol's height, can make progress when fragmenting without hanging the browser."> <style> #a { column-count: 2; } #b { box-decoration-break: clone; padding: 4px 0px; border: 1px dotted black; } * { height: 19%; } </style> Hopefully this doesn't hang. <div id="a"> <div id="b">