RESOLVED FIXED 227652
Shadow host stops rendering after removing a slot, updating style, then its assigned node 
https://bugs.webkit.org/show_bug.cgi?id=227652
Summary Shadow host stops rendering after removing a slot, updating style, then its a...
David Iglesias
Reported 2021-07-02 17:43:21 PDT
Given this DOM: div#container :shadowRoot | div#bg | slot[name=something] ` div#slotted[slot=something] If the slot element is removed from the shadow root, and then (in a separate timeout) div#slotted is removed from the light DOM, the div#container will lose its layout and become invisible on the page. Minimal repro case: * https://jsfiddle.net/ditman/rmwqjLah/ The following things happen in the link above: 1. The output becomes yellow (background of #container) 2. The output becomes green, and has some text (the slot inside of a div#bg container has been appended into the Shadow DOM) 3. The output becomes green, without text (the slot has been deleted from the Shadow DOM) 4. The output becomes RED (the div#slotted is removed from the Light DOM, and #container loses layout, revealing the body of the page behind it!) I'd expect that step 4 stays the same as step 3. I've tested other browsers and that's what they do. I've seen this bug with Safari 14 and 15 (Tech preview) in MacOS 11.4 (Big Sur) and stock Safari on iOS 14.6.
Attachments
Reduction (771 bytes, text/html)
2021-07-07 20:54 PDT, Ryosuke Niwa 		no flags
Details
patch (3.58 KB, patch)
2021-07-08 06:21 PDT, Antti Koivisto 		no flags
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
David Iglesias
Comment 1 2021-07-02 18:04:32 PDT
Original user report (Flutter Web): https://github.com/flutter/flutter/issues/84832 Issue workaround here: https://github.com/flutter/engine/pull/27154 Cleanup ticket: https://github.com/flutter/flutter/issues/85816
Ryosuke Niwa
Comment 2 2021-07-07 12:34:05 PDT
I can reproduce this at r279638.
David Iglesias
Comment 3 2021-07-07 19:38:34 PDT
Thanks for verifying in a more recent build! (I couldn't get builds from the archives to run in my corporate laptop properly!)
Ryosuke Niwa
Comment 4 2021-07-07 20:54:24 PDT
Created attachment 433113 [details] Reduction
Antti Koivisto
Comment 5 2021-07-08 06:21:22 PDT
Created attachment 433128 [details] patch
EWS
Comment 6 2021-07-08 07:47:42 PDT
Committed r279721 (239509@main): <https://commits.webkit.org/239509@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 433128 [details].
Radar WebKit Bug Importer
Comment 7 2021-07-08 07:48:17 PDT
<rdar://problem/80323422>
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