Created attachment 376398 [details]
STR: Load the minimal test case. the callback will put the intersectionRatio on the page.
Expected: The intersectionRatio should be exactly 1 in this case because the element is entirely in the viewport.
Actual: It's 1.0270270109176636.
The spec states it should be a number between 0 and 1. https://w3c.github.io/IntersectionObserver/#dom-intersectionobserverentry-intersectionratio
This is also reproducible on Chrome but not Firefox.
Tested on Release 89 (Safari 13.1, WebKit 14609.1.1)
Filed on Chromium as https://bugs.chromium.org/p/chromium/issues/detail?id=994298
Still producible on WebKit Nightly Version 12.1.2 (14607.3.9, 609+)
Created attachment 378731 [details]
Comment on attachment 378731 [details]
Clearing flags on attachment: 378731
Committed r249845: <https://trac.webkit.org/changeset/249845>
All reviewed patches have been landed. Closing bug.