Scrolling does not work correctly in XHTML documents

When scrollIntoView ascends the element tree it tests the tagName property of elements to work out when it has reached the <body>:

scroll-into-view/scrollIntoView.js

Line 202 in 2a3c18a

if(el.parentElement.tagName === 'BODY'){

In an XHTML document (example) document.body.tagName returns "body" rather than "BODY" as it does in HTML documents. See MDN docs.

The result is that the test incorrectly fails and the document is scrolled to the wrong location. In some limited testing, making the test case insensitive appears to resolve the issue.

Published as 1.16.2, sorry I didn't get around to it sooner.