For some reason this only works for list boxes, but doesn't work for other elements like text areas or iframes. It also happens in GTK port when AC mode is forced (async scrolling is used).
Could it be that this regressed in r257268? Simon, is this the expected behavior with current trunk? ScrollingTree::scrollingNodeForPoint() always returns the root node.
Was Nicosia/Coordinated Graphics relying on that geometry? It was very broken in many cases, so shipping anything that used it was a mistake. I'll be adding new code that fixes this for macOS; Nicosia/Coordinated Graphics should follow what I'm doing.
(In reply to Simon Fraser (smfr) from comment #2) > Was Nicosia/Coordinated Graphics relying on that geometry? It was very > broken in many cases, so shipping anything that used it was a mistake. > > I'll be adding new code that fixes this for macOS; Nicosia/Coordinated > Graphics should follow what I'm doing. The implementation was implicitly relying on it, but nothing shipped with it. We'll disable async overflow scrolling for now, and follow what macOS will be doing.
Created attachment 393012 [details] Patch
Comment on attachment 393012 [details] Patch Clearing flags on attachment: 393012 Committed r258134: <https://trac.webkit.org/changeset/258134>
All reviewed patches have been landed. Closing bug.