Update wp_parse_url() for performance and legacy code removal

src/wp-includes/http.php

@@ -710,31 +710,58 @@ function ms_allowed_http_request_hosts( $is_external, $host ) {
  *               PHP_URL_PORT - integer when it does. See parse_url()'s return values.
  */
 function wp_parse_url( $url, $component = -1 ) {
-	$to_unset = array();
-	$url      = (string) $url;
 
-	if ( str_starts_with( $url, '//' ) ) {
-		$to_unset[] = 'scheme';
-		$url        = 'placeholder:' . $url;
-	} elseif ( str_starts_with( $url, '/' ) ) {
-		$to_unset[] = 'scheme';
-		$to_unset[] = 'host';
-		$url        = 'placeholder://placeholder' . $url;
-	}
+	switch ( $component ) {
 
-	$parts = parse_url( $url );
+		case -1:
+		case PHP_URL_PATH:
+		case PHP_URL_QUERY:
+		case PHP_URL_SCHEME:
+		case PHP_URL_HOST:
+		case PHP_URL_PORT:
+		case PHP_URL_USER:
+		case PHP_URL_PASS:
+		case PHP_URL_FRAGMENT:
+			break;
 
-	if ( false === $parts ) {
-		// Parsing failure.
-		return $parts;
-	}
+		case 'path':
+			$component = PHP_URL_PATH;
+			break;
+
+		case 'query':
+			$component = PHP_URL_QUERY;
+			break;
+
+		case 'scheme':
+			$component = PHP_URL_SCHEME;
+			break;
+
+		case 'host':
+			$component = PHP_URL_HOST;
+			break;
+
+		case 'port':
+			$component = PHP_URL_PORT;
+			break;
+
+		case 'user':
+			$component = PHP_URL_USER;
+			break;
+
+		case 'pass':
+			$component = PHP_URL_PASS;
+			break;
+
+		case 'fragment':
+			$component = PHP_URL_FRAGMENT;
+			break;
 
-	// Remove the placeholder values.
-	foreach ( $to_unset as $key ) {
-		unset( $parts[ $key ] );
+		default:
+			return null;
+			break;
 	}
 
-	return _get_component_from_parsed_url_array( $parts, $component );
+	return parse_url( (string) $url, $component );
 }
 
 /**