Instant Search: Closing the search overlay on a search page temporarily re-enables body scroll

1. Enable instant search.
2. Open up /?s=foo
3. Reduce your browser size to that of mobile for best visibility and to make sure you have enough content to scroll.
4. Click on the X button of the search overlay – the body scroll will be restored making a scroll bar appear until the redirect to the homepage is done.

https://videopress.com/v/dEofaICk

Original report: p8oabR-DS-p2#comment-5129

No file or test is named. Reproduce the issue at /?s=foo with a mobile-sized viewport, then trace the instant-search overlay close behavior and redirect. Done means closing the overlay does not temporarily restore body scrolling or show a scrollbar before navigation completes.

Written by the indexing model from the issue text.