custom header stores full URL in database

[tverlaan]

set_header_image is storing the full URL to the custom header in the database. It should only store the relative path in the database and get_header_image should prepend the relative path with get_bloginfo('url'). This makes migrating your site easier. Or you can have a develop and live environment with an easy database sync (my particular issue).

set_header_image
Replace:

$choice['url'] = esc_url_raw( $choice['url'] );

With:

$choice['url'] = str_replace( get_bloginfo('url'), '', esc_url_raw( $choice['url'] ) );

or find another method of getting the relative URL

header_image
then add the bloginfo URL to header_image (and probably a few other places).

function header_image() {
	echo esc_url( get_bloginfo('url').get_header_image() );
}

[obenland]

Why not use content_url()?
For back compat we'd have to add a check if the URL we're appending is indeed relative.

[michalzuber]

Related #28926