Created attachment 412456 [details] Minimal working example In the attached example, when using Safari 14 or Safari Technology Preview, moving the mouse over the different elements of the page will result in the CSS rule `table td:first-of-type {color: red;}` being applied to potentially any arbitrary sibling in a group. Only the first `td` in each group should be colored red, but mousing over and out of the other `td` elements results in these element also being colored red. This also occurs with various other properties.
<rdar://problem/70749584>
style sharing bug perhaps?
A decent theory is that the animation code is losing the bits that prevent style sharing.
Yeah, disabling style sharing makes the bug go away.
Created attachment 417380 [details] patch
Created attachment 417386 [details] patch
Committed r271367: <https://trac.webkit.org/changeset/271367> All reviewed patches have been landed. Closing bug and clearing flags on attachment 417386 [details].