See https://github.com/whatwg/html/pull/6735 . No web platform tests, unfortunately. https://bugs.webkit.org/show_bug.cgi?id=187084 may be related; perhaps WebKit wants to fire cancel in such a case, instead of change.
<rdar://problem/80340803>
Pull request: https://github.com/WebKit/WebKit/pull/4986
Committed 255394@main (059f8069cb4a): <https://commits.webkit.org/255394@main> Reviewed commits have been landed. Closing PR #4986 and removing active labels.