Although a resize handle is shown, the pink pseudo-element in the testcase above cannot actually be resized. css3-ui states that the resize property applies to “elements with ‘overflow’ other than visible”, which includes pseudo-elements.
(In reply to comment #0) > css3-ui states that the resize property applies to “elements with ‘overflow’ > other than visible”, which includes pseudo-elements. The css3-ui spec now also says "Implementations should not apply the resize property to generated content." That includes the pseudo-element in the dabblet testcase here. Spec link: http://dev.w3.org/csswg/css-ui/#resize So, I think the (current) expected behavior here is that WebKit shouldn't be showing a resizer on that pseudo-element. (The resize property "should not apply", i.e. it shouldn't affect rendering at all.) Incidentally, Firefox/Gecko recently changed to have that behavior (not showing a resizer) in https://bugzilla.mozilla.org/show_bug.cgi?id=1043537
Safari continues to show a resize handle, when it should not.
<rdar://problem/96983000>
https://wpt.fyi/results/css/css-ui/resize-generated-content.html?label=master&label=experimental&aligned&q=safari%3Afail Live Link: http://wpt.live/css/css-ui/resize-generated-content.html