Don't prefetch the current page

[joetannenbaum]

Here's the scenario:

• User is on /users
• There is a Link to /users that prefetches on hover on the page
• If they hover that Link it will prefetch page and refresh the data on the current page
• If there is any changed form state, etc it gets reset back to its original state

My solution is: if we are trying to prefetch the current page, just don't. I can't think of a scenario where this is useful, we're already on the page, so we just abort it before it even kicks off.

[joetannenbaum]

Fixes: #2066

[Jussi-Mannisto]

Strict href comparison doesn't take fragments into account, e.g. /about#contact. These links would still get prefetched after this fix.

I used this comparison in my workaround:

function isCurrentPage(href) {
	const url = new URL(href, window.location.origin);
	const current = window.location;

	return url.origin + url.pathname + url.search === current.origin + current.pathname + current.search;
}