Customizer Theme Switcher: Live previewing a theme breaks on subfolder installs

[ericlewis]

Live previewing a theme on a subfolder install (e.g. site.com/wordpress) breaks, and will send you to a 404 page.

[ericlewis]

In attachment:31889.mp4​, a screencast of the bug.

[westonruter]

Related: #31782

[ericlewis]

This is because of the way the URL is being built for the theme preview link.

I've modified this logic appropriately in attachment:31896.diff​

[ocean90]

I think this can be simplified to set_url_scheme( 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'] ), see 31896.2.diff​.

[ocean90]

In 32086:

Customizer Theme Switcher: Fix preview URL for subfolder installs.

Use $_SERVER['HTTP_HOST'] and $_SERVER['REQUEST_URI'] instead of site_url() and $_SERVER['REQUEST_URI'].

fixes #31896.

[ocean90]

In 32134:

Customizer: Escape theme preview URLs.

props johnbillion, ocean90.
see #31896.