WP_CONTENT_URL based defines do not work over SSL (HTTPS)

Nextgen Gallery and a few other plugins I have installed seem to never want to use https urls when the rest of the site does. I have tracked this down to fact that the get_option(‘siteurl’) is not filtered using is_ssl() to ensure the proper URL scheme. This means that any plugin (or theme or whatever) that makes use of a defined URL will always reference http instead of properly switching to https, since the defined URLs are always based on WP_CONTENT_URL (such as WP_PLUGIN_URL).

The proper fix for this would ?probably? be for WP to modify their ‘wp-includes/default-filters.php’ file to have the filter listed below, but for now the easiest thing for me to do is to paste the code below in to my wp-settings.php file, just above the first reference to “WP_CONTENT_URL” (which is line 390 in WP ver 2.9).

Search for:

if ( !defined('WP_CONTENT_URL') )
	define( 'WP_CONTENT_URL', get_option('siteurl') . '/wp-content'); // full url - WP_CONTENT_DIR is defined further up

Replace with:

// Fix the URL root for SSL
function fix_ssl_siteurl($url) {
	$scheme = (is_ssl() ? 'https' : 'http');
	if(0 === strpos($url, 'http')) {
		if(is_ssl())
			$url = str_replace('https://', "{$scheme}://", $url);
	}

    return $url;
}
add_filter('option_siteurl', fix_ssl_siteurl);
add_filter('option_home', fix_ssl_siteurl);

if ( !defined('WP_CONTENT_URL') )
	define( 'WP_CONTENT_URL', get_option('siteurl') . '/wp-content'); // full url - WP_CONTENT_DIR is defined further up

It would be great if this could be fixed in WordPress in the same manner than content_url() was recently added.