Adding upstream version 6.4.3+dfsg1.upstream/6.4.3+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 783 insertions, 0 deletions

diff --git a/wp-includes/http.php b/wp-includes/http.php
new file mode 100644
index 0000000..e1738be
--- /dev/null
+++ b/wp-includes/http.php
@@ -0,0 +1,783 @@
+<?php
+/**
+ * Core HTTP Request API
+ *
+ * Standardizes the HTTP requests for WordPress. Handles cookies, gzip encoding and decoding, chunk
+ * decoding, if HTTP 1.1 and various other difficult HTTP protocol implementations.
+ *
+ * @package WordPress
+ * @subpackage HTTP
+ */
+
+/**
+ * Returns the initialized WP_Http Object
+ *
+ * @since 2.7.0
+ * @access private
+ *
+ * @return WP_Http HTTP Transport object.
+ */
+function _wp_http_get_object() {
+	static $http = null;
+
+	if ( is_null( $http ) ) {
+		$http = new WP_Http();
+	}
+	return $http;
+}
+
+/**
+ * Retrieve the raw response from a safe HTTP request.
+ *
+ * This function is ideal when the HTTP request is being made to an arbitrary
+ * URL. The URL is validated to avoid redirection and request forgery attacks.
+ *
+ * @since 3.6.0
+ *
+ * @see wp_remote_request() For more information on the response array format.
+ * @see WP_Http::request() For default arguments information.
+ *
+ * @param string $url  URL to retrieve.
+ * @param array  $args Optional. Request arguments. Default empty array.
+ *                     See WP_Http::request() for information on accepted arguments.
+ * @return array|WP_Error The response or WP_Error on failure.
+ */
+function wp_safe_remote_request( $url, $args = array() ) {
+	$args['reject_unsafe_urls'] = true;
+	$http                       = _wp_http_get_object();
+	return $http->request( $url, $args );
+}
+
+/**
+ * Retrieve the raw response from a safe HTTP request using the GET method.
+ *
+ * This function is ideal when the HTTP request is being made to an arbitrary
+ * URL. The URL is validated to avoid redirection and request forgery attacks.
+ *
+ * @since 3.6.0
+ *
+ * @see wp_remote_request() For more information on the response array format.
+ * @see WP_Http::request() For default arguments information.
+ *
+ * @param string $url  URL to retrieve.
+ * @param array  $args Optional. Request arguments. Default empty array.
+ *                     See WP_Http::request() for information on accepted arguments.
+ * @return array|WP_Error The response or WP_Error on failure.
+ */
+function wp_safe_remote_get( $url, $args = array() ) {
+	$args['reject_unsafe_urls'] = true;
+	$http                       = _wp_http_get_object();
+	return $http->get( $url, $args );
+}
+
+/**
+ * Retrieve the raw response from a safe HTTP request using the POST method.
+ *
+ * This function is ideal when the HTTP request is being made to an arbitrary
+ * URL. The URL is validated to avoid redirection and request forgery attacks.
+ *
+ * @since 3.6.0
+ *
+ * @see wp_remote_request() For more information on the response array format.
+ * @see WP_Http::request() For default arguments information.
+ *
+ * @param string $url  URL to retrieve.
+ * @param array  $args Optional. Request arguments. Default empty array.
+ *                     See WP_Http::request() for information on accepted arguments.
+ * @return array|WP_Error The response or WP_Error on failure.
+ */
+function wp_safe_remote_post( $url, $args = array() ) {
+	$args['reject_unsafe_urls'] = true;
+	$http                       = _wp_http_get_object();
+	return $http->post( $url, $args );
+}
+
+/**
+ * Retrieve the raw response from a safe HTTP request using the HEAD method.
+ *
+ * This function is ideal when the HTTP request is being made to an arbitrary
+ * URL. The URL is validated to avoid redirection and request forgery attacks.
+ *
+ * @since 3.6.0
+ *
+ * @see wp_remote_request() For more information on the response array format.
+ * @see WP_Http::request() For default arguments information.
+ *
+ * @param string $url  URL to retrieve.
+ * @param array  $args Optional. Request arguments. Default empty array.
+ *                     See WP_Http::request() for information on accepted arguments.
+ * @return array|WP_Error The response or WP_Error on failure.
+ */
+function wp_safe_remote_head( $url, $args = array() ) {
+	$args['reject_unsafe_urls'] = true;
+	$http                       = _wp_http_get_object();
+	return $http->head( $url, $args );
+}
+
+/**
+ * Performs an HTTP request and returns its response.
+ *
+ * There are other API functions available which abstract away the HTTP method:
+ *
+ *  - Default 'GET'  for wp_remote_get()
+ *  - Default 'POST' for wp_remote_post()
+ *  - Default 'HEAD' for wp_remote_head()
+ *
+ * @since 2.7.0
+ *
+ * @see WP_Http::request() For information on default arguments.
+ *
+ * @param string $url  URL to retrieve.
+ * @param array  $args Optional. Request arguments. Default empty array.
+ *                     See WP_Http::request() for information on accepted arguments.
+ * @return array|WP_Error {
+ *     The response array or a WP_Error on failure.
+ *
+ *     @type string[]                       $headers       Array of response headers keyed by their name.
+ *     @type string                         $body          Response body.
+ *     @type array                          $response      {
+ *         Data about the HTTP response.
+ *
+ *         @type int|false    $code    HTTP response code.
+ *         @type string|false $message HTTP response message.
+ *     }
+ *     @type WP_HTTP_Cookie[]               $cookies       Array of response cookies.
+ *     @type WP_HTTP_Requests_Response|null $http_response Raw HTTP response object.
+ * }
+ */
+function wp_remote_request( $url, $args = array() ) {
+	$http = _wp_http_get_object();
+	return $http->request( $url, $args );
+}
+
+/**
+ * Performs an HTTP request using the GET method and returns its response.
+ *
+ * @since 2.7.0
+ *
+ * @see wp_remote_request() For more information on the response array format.
+ * @see WP_Http::request() For default arguments information.
+ *
+ * @param string $url  URL to retrieve.
+ * @param array  $args Optional. Request arguments. Default empty array.
+ *                     See WP_Http::request() for information on accepted arguments.
+ * @return array|WP_Error The response or WP_Error on failure.
+ */
+function wp_remote_get( $url, $args = array() ) {
+	$http = _wp_http_get_object();
+	return $http->get( $url, $args );
+}
+
+/**
+ * Performs an HTTP request using the POST method and returns its response.
+ *
+ * @since 2.7.0
+ *
+ * @see wp_remote_request() For more information on the response array format.
+ * @see WP_Http::request() For default arguments information.
+ *
+ * @param string $url  URL to retrieve.
+ * @param array  $args Optional. Request arguments. Default empty array.
+ *                     See WP_Http::request() for information on accepted arguments.
+ * @return array|WP_Error The response or WP_Error on failure.
+ */
+function wp_remote_post( $url, $args = array() ) {
+	$http = _wp_http_get_object();
+	return $http->post( $url, $args );
+}
+
+/**
+ * Performs an HTTP request using the HEAD method and returns its response.
+ *
+ * @since 2.7.0
+ *
+ * @see wp_remote_request() For more information on the response array format.
+ * @see WP_Http::request() For default arguments information.
+ *
+ * @param string $url  URL to retrieve.
+ * @param array  $args Optional. Request arguments. Default empty array.
+ *                     See WP_Http::request() for information on accepted arguments.
+ * @return array|WP_Error The response or WP_Error on failure.
+ */
+function wp_remote_head( $url, $args = array() ) {
+	$http = _wp_http_get_object();
+	return $http->head( $url, $args );
+}
+
+/**
+ * Retrieve only the headers from the raw response.
+ *
+ * @since 2.7.0
+ * @since 4.6.0 Return value changed from an array to an WpOrg\Requests\Utility\CaseInsensitiveDictionary instance.
+ *
+ * @see \WpOrg\Requests\Utility\CaseInsensitiveDictionary
+ *
+ * @param array|WP_Error $response HTTP response.
+ * @return \WpOrg\Requests\Utility\CaseInsensitiveDictionary|array The headers of the response, or empty array
+ *                                                                 if incorrect parameter given.
+ */
+function wp_remote_retrieve_headers( $response ) {
+	if ( is_wp_error( $response ) || ! isset( $response['headers'] ) ) {
+		return array();
+	}
+
+	return $response['headers'];
+}
+
+/**
+ * Retrieve a single header by name from the raw response.
+ *
+ * @since 2.7.0
+ *
+ * @param array|WP_Error $response HTTP response.
+ * @param string         $header   Header name to retrieve value from.
+ * @return array|string The header(s) value(s). Array if multiple headers with the same name are retrieved.
+ *                      Empty string if incorrect parameter given, or if the header doesn't exist.
+ */
+function wp_remote_retrieve_header( $response, $header ) {
+	if ( is_wp_error( $response ) || ! isset( $response['headers'] ) ) {
+		return '';
+	}
+
+	if ( isset( $response['headers'][ $header ] ) ) {
+		return $response['headers'][ $header ];
+	}
+
+	return '';
+}
+
+/**
+ * Retrieve only the response code from the raw response.
+ *
+ * Will return an empty string if incorrect parameter value is given.
+ *
+ * @since 2.7.0
+ *
+ * @param array|WP_Error $response HTTP response.
+ * @return int|string The response code as an integer. Empty string if incorrect parameter given.
+ */
+function wp_remote_retrieve_response_code( $response ) {
+	if ( is_wp_error( $response ) || ! isset( $response['response'] ) || ! is_array( $response['response'] ) ) {
+		return '';
+	}
+
+	return $response['response']['code'];
+}
+
+/**
+ * Retrieve only the response message from the raw response.
+ *
+ * Will return an empty string if incorrect parameter value is given.
+ *
+ * @since 2.7.0
+ *
+ * @param array|WP_Error $response HTTP response.
+ * @return string The response message. Empty string if incorrect parameter given.
+ */
+function wp_remote_retrieve_response_message( $response ) {
+	if ( is_wp_error( $response ) || ! isset( $response['response'] ) || ! is_array( $response['response'] ) ) {
+		return '';
+	}
+
+	return $response['response']['message'];
+}
+
+/**
+ * Retrieve only the body from the raw response.
+ *
+ * @since 2.7.0
+ *
+ * @param array|WP_Error $response HTTP response.
+ * @return string The body of the response. Empty string if no body or incorrect parameter given.
+ */
+function wp_remote_retrieve_body( $response ) {
+	if ( is_wp_error( $response ) || ! isset( $response['body'] ) ) {
+		return '';
+	}
+
+	return $response['body'];
+}
+
+/**
+ * Retrieve only the cookies from the raw response.
+ *
+ * @since 4.4.0
+ *
+ * @param array|WP_Error $response HTTP response.
+ * @return WP_Http_Cookie[] An array of `WP_Http_Cookie` objects from the response.
+ *                          Empty array if there are none, or the response is a WP_Error.
+ */
+function wp_remote_retrieve_cookies( $response ) {
+	if ( is_wp_error( $response ) || empty( $response['cookies'] ) ) {
+		return array();
+	}
+
+	return $response['cookies'];
+}
+
+/**
+ * Retrieve a single cookie by name from the raw response.
+ *
+ * @since 4.4.0
+ *
+ * @param array|WP_Error $response HTTP response.
+ * @param string         $name     The name of the cookie to retrieve.
+ * @return WP_Http_Cookie|string The `WP_Http_Cookie` object, or empty string
+ *                               if the cookie is not present in the response.
+ */
+function wp_remote_retrieve_cookie( $response, $name ) {
+	$cookies = wp_remote_retrieve_cookies( $response );
+
+	if ( empty( $cookies ) ) {
+		return '';
+	}
+
+	foreach ( $cookies as $cookie ) {
+		if ( $cookie->name === $name ) {
+			return $cookie;
+		}
+	}
+
+	return '';
+}
+
+/**
+ * Retrieve a single cookie's value by name from the raw response.
+ *
+ * @since 4.4.0
+ *
+ * @param array|WP_Error $response HTTP response.
+ * @param string         $name     The name of the cookie to retrieve.
+ * @return string The value of the cookie, or empty string
+ *                if the cookie is not present in the response.
+ */
+function wp_remote_retrieve_cookie_value( $response, $name ) {
+	$cookie = wp_remote_retrieve_cookie( $response, $name );
+
+	if ( ! ( $cookie instanceof WP_Http_Cookie ) ) {
+		return '';
+	}
+
+	return $cookie->value;
+}
+
+/**
+ * Determines if there is an HTTP Transport that can process this request.
+ *
+ * @since 3.2.0
+ *
+ * @param array  $capabilities Array of capabilities to test or a wp_remote_request() $args array.
+ * @param string $url          Optional. If given, will check if the URL requires SSL and adds
+ *                             that requirement to the capabilities array.
+ *
+ * @return bool
+ */
+function wp_http_supports( $capabilities = array(), $url = null ) {
+	$http = _wp_http_get_object();
+
+	$capabilities = wp_parse_args( $capabilities );
+
+	$count = count( $capabilities );
+
+	// If we have a numeric $capabilities array, spoof a wp_remote_request() associative $args array.
+	if ( $count && count( array_filter( array_keys( $capabilities ), 'is_numeric' ) ) === $count ) {
+		$capabilities = array_combine( array_values( $capabilities ), array_fill( 0, $count, true ) );
+	}
+
+	if ( $url && ! isset( $capabilities['ssl'] ) ) {
+		$scheme = parse_url( $url, PHP_URL_SCHEME );
+		if ( 'https' === $scheme || 'ssl' === $scheme ) {
+			$capabilities['ssl'] = true;
+		}
+	}
+
+	return (bool) $http->_get_first_available_transport( $capabilities );
+}
+
+/**
+ * Get the HTTP Origin of the current request.
+ *
+ * @since 3.4.0
+ *
+ * @return string URL of the origin. Empty string if no origin.
+ */
+function get_http_origin() {
+	$origin = '';
+	if ( ! empty( $_SERVER['HTTP_ORIGIN'] ) ) {
+		$origin = $_SERVER['HTTP_ORIGIN'];
+	}
+
+	/**
+	 * Change the origin of an HTTP request.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param string $origin The original origin for the request.
+	 */
+	return apply_filters( 'http_origin', $origin );
+}
+
+/**
+ * Retrieve list of allowed HTTP origins.
+ *
+ * @since 3.4.0
+ *
+ * @return string[] Array of origin URLs.
+ */
+function get_allowed_http_origins() {
+	$admin_origin = parse_url( admin_url() );
+	$home_origin  = parse_url( home_url() );
+
+	// @todo Preserve port?
+	$allowed_origins = array_unique(
+		array(
+			'http://' . $admin_origin['host'],
+			'https://' . $admin_origin['host'],
+			'http://' . $home_origin['host'],
+			'https://' . $home_origin['host'],
+		)
+	);
+
+	/**
+	 * Change the origin types allowed for HTTP requests.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param string[] $allowed_origins {
+	 *     Array of default allowed HTTP origins.
+	 *
+	 *     @type string $0 Non-secure URL for admin origin.
+	 *     @type string $1 Secure URL for admin origin.
+	 *     @type string $2 Non-secure URL for home origin.
+	 *     @type string $3 Secure URL for home origin.
+	 * }
+	 */
+	return apply_filters( 'allowed_http_origins', $allowed_origins );
+}
+
+/**
+ * Determines if the HTTP origin is an authorized one.
+ *
+ * @since 3.4.0
+ *
+ * @param string|null $origin Origin URL. If not provided, the value of get_http_origin() is used.
+ * @return string Origin URL if allowed, empty string if not.
+ */
+function is_allowed_http_origin( $origin = null ) {
+	$origin_arg = $origin;
+
+	if ( null === $origin ) {
+		$origin = get_http_origin();
+	}
+
+	if ( $origin && ! in_array( $origin, get_allowed_http_origins(), true ) ) {
+		$origin = '';
+	}
+
+	/**
+	 * Change the allowed HTTP origin result.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param string $origin     Origin URL if allowed, empty string if not.
+	 * @param string $origin_arg Original origin string passed into is_allowed_http_origin function.
+	 */
+	return apply_filters( 'allowed_http_origin', $origin, $origin_arg );
+}
+
+/**
+ * Send Access-Control-Allow-Origin and related headers if the current request
+ * is from an allowed origin.
+ *
+ * If the request is an OPTIONS request, the script exits with either access
+ * control headers sent, or a 403 response if the origin is not allowed. For
+ * other request methods, you will receive a return value.
+ *
+ * @since 3.4.0
+ *
+ * @return string|false Returns the origin URL if headers are sent. Returns false
+ *                      if headers are not sent.
+ */
+function send_origin_headers() {
+	$origin = get_http_origin();
+
+	if ( is_allowed_http_origin( $origin ) ) {
+		header( 'Access-Control-Allow-Origin: ' . $origin );
+		header( 'Access-Control-Allow-Credentials: true' );
+		if ( 'OPTIONS' === $_SERVER['REQUEST_METHOD'] ) {
+			exit;
+		}
+		return $origin;
+	}
+
+	if ( 'OPTIONS' === $_SERVER['REQUEST_METHOD'] ) {
+		status_header( 403 );
+		exit;
+	}
+
+	return false;
+}
+
+/**
+ * Validate a URL for safe use in the HTTP API.
+ *
+ * @since 3.5.2
+ *
+ * @param string $url Request URL.
+ * @return string|false URL or false on failure.
+ */
+function wp_http_validate_url( $url ) {
+	if ( ! is_string( $url ) || '' === $url || is_numeric( $url ) ) {
+		return false;
+	}
+
+	$original_url = $url;
+	$url          = wp_kses_bad_protocol( $url, array( 'http', 'https' ) );
+	if ( ! $url || strtolower( $url ) !== strtolower( $original_url ) ) {
+		return false;
+	}
+
+	$parsed_url = parse_url( $url );
+	if ( ! $parsed_url || empty( $parsed_url['host'] ) ) {
+		return false;
+	}
+
+	if ( isset( $parsed_url['user'] ) || isset( $parsed_url['pass'] ) ) {
+		return false;
+	}
+
+	if ( false !== strpbrk( $parsed_url['host'], ':#?[]' ) ) {
+		return false;
+	}
+
+	$parsed_home = parse_url( get_option( 'home' ) );
+	$same_host   = isset( $parsed_home['host'] ) && strtolower( $parsed_home['host'] ) === strtolower( $parsed_url['host'] );
+	$host        = trim( $parsed_url['host'], '.' );
+
+	if ( ! $same_host ) {
+		if ( preg_match( '#^(([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)\.){3}([1-9]?\d|1\d\d|25[0-5]|2[0-4]\d)$#', $host ) ) {
+			$ip = $host;
+		} else {
+			$ip = gethostbyname( $host );
+			if ( $ip === $host ) { // Error condition for gethostbyname().
+				return false;
+			}
+		}
+		if ( $ip ) {
+			$parts = array_map( 'intval', explode( '.', $ip ) );
+			if ( 127 === $parts[0] || 10 === $parts[0] || 0 === $parts[0]
+				|| ( 172 === $parts[0] && 16 <= $parts[1] && 31 >= $parts[1] )
+				|| ( 192 === $parts[0] && 168 === $parts[1] )
+			) {
+				// If host appears local, reject unless specifically allowed.
+				/**
+				 * Check if HTTP request is external or not.
+				 *
+				 * Allows to change and allow external requests for the HTTP request.
+				 *
+				 * @since 3.6.0
+				 *
+				 * @param bool   $external Whether HTTP request is external or not.
+				 * @param string $host     Host name of the requested URL.
+				 * @param string $url      Requested URL.
+				 */
+				if ( ! apply_filters( 'http_request_host_is_external', false, $host, $url ) ) {
+					return false;
+				}
+			}
+		}
+	}
+
+	if ( empty( $parsed_url['port'] ) ) {
+		return $url;
+	}
+
+	$port = $parsed_url['port'];
+
+	/**
+	 * Controls the list of ports considered safe in HTTP API.
+	 *
+	 * Allows to change and allow external requests for the HTTP request.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param int[]  $allowed_ports Array of integers for valid ports.
+	 * @param string $host          Host name of the requested URL.
+	 * @param string $url           Requested URL.
+	 */
+	$allowed_ports = apply_filters( 'http_allowed_safe_ports', array( 80, 443, 8080 ), $host, $url );
+	if ( is_array( $allowed_ports ) && in_array( $port, $allowed_ports, true ) ) {
+		return $url;
+	}
+
+	if ( $parsed_home && $same_host && isset( $parsed_home['port'] ) && $parsed_home['port'] === $port ) {
+		return $url;
+	}
+
+	return false;
+}
+
+/**
+ * Mark allowed redirect hosts safe for HTTP requests as well.
+ *
+ * Attached to the {@see 'http_request_host_is_external'} filter.
+ *
+ * @since 3.6.0
+ *
+ * @param bool   $is_external
+ * @param string $host
+ * @return bool
+ */
+function allowed_http_request_hosts( $is_external, $host ) {
+	if ( ! $is_external && wp_validate_redirect( 'http://' . $host ) ) {
+		$is_external = true;
+	}
+	return $is_external;
+}
+
+/**
+ * Adds any domain in a multisite installation for safe HTTP requests to the
+ * allowed list.
+ *
+ * Attached to the {@see 'http_request_host_is_external'} filter.
+ *
+ * @since 3.6.0
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
+ *
+ * @param bool   $is_external
+ * @param string $host
+ * @return bool
+ */
+function ms_allowed_http_request_hosts( $is_external, $host ) {
+	global $wpdb;
+	static $queried = array();
+	if ( $is_external ) {
+		return $is_external;
+	}
+	if ( get_network()->domain === $host ) {
+		return true;
+	}
+	if ( isset( $queried[ $host ] ) ) {
+		return $queried[ $host ];
+	}
+	$queried[ $host ] = (bool) $wpdb->get_var( $wpdb->prepare( "SELECT domain FROM $wpdb->blogs WHERE domain = %s LIMIT 1", $host ) );
+	return $queried[ $host ];
+}
+
+/**
+ * A wrapper for PHP's parse_url() function that handles consistency in the return values
+ * across PHP versions.
+ *
+ * PHP 5.4.7 expanded parse_url()'s ability to handle non-absolute URLs, including
+ * schemeless and relative URLs with "://" in the path. This function works around
+ * those limitations providing a standard output on PHP 5.2~5.4+.
+ *
+ * Secondly, across various PHP versions, schemeless URLs containing a ":" in the query
+ * are being handled inconsistently. This function works around those differences as well.
+ *
+ * @since 4.4.0
+ * @since 4.7.0 The `$component` parameter was added for parity with PHP's `parse_url()`.
+ *
+ * @link https://www.php.net/manual/en/function.parse-url.php
+ *
+ * @param string $url       The URL to parse.
+ * @param int    $component The specific component to retrieve. Use one of the PHP
+ *                          predefined constants to specify which one.
+ *                          Defaults to -1 (= return all parts as an array).
+ * @return mixed False on parse failure; Array of URL components on success;
+ *               When a specific component has been requested: null if the component
+ *               doesn't exist in the given URL; a string or - in the case of
+ *               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;
+	}
+
+	$parts = parse_url( $url );
+
+	if ( false === $parts ) {
+		// Parsing failure.
+		return $parts;
+	}
+
+	// Remove the placeholder values.
+	foreach ( $to_unset as $key ) {
+		unset( $parts[ $key ] );
+	}
+
+	return _get_component_from_parsed_url_array( $parts, $component );
+}
+
+/**
+ * Retrieve a specific component from a parsed URL array.
+ *
+ * @internal
+ *
+ * @since 4.7.0
+ * @access private
+ *
+ * @link https://www.php.net/manual/en/function.parse-url.php
+ *
+ * @param array|false $url_parts The parsed URL. Can be false if the URL failed to parse.
+ * @param int         $component The specific component to retrieve. Use one of the PHP
+ *                               predefined constants to specify which one.
+ *                               Defaults to -1 (= return all parts as an array).
+ * @return mixed False on parse failure; Array of URL components on success;
+ *               When a specific component has been requested: null if the component
+ *               doesn't exist in the given URL; a string or - in the case of
+ *               PHP_URL_PORT - integer when it does. See parse_url()'s return values.
+ */
+function _get_component_from_parsed_url_array( $url_parts, $component = -1 ) {
+	if ( -1 === $component ) {
+		return $url_parts;
+	}
+
+	$key = _wp_translate_php_url_constant_to_key( $component );
+	if ( false !== $key && is_array( $url_parts ) && isset( $url_parts[ $key ] ) ) {
+		return $url_parts[ $key ];
+	} else {
+		return null;
+	}
+}
+
+/**
+ * Translate a PHP_URL_* constant to the named array keys PHP uses.
+ *
+ * @internal
+ *
+ * @since 4.7.0
+ * @access private
+ *
+ * @link https://www.php.net/manual/en/url.constants.php
+ *
+ * @param int $constant PHP_URL_* constant.
+ * @return string|false The named key or false.
+ */
+function _wp_translate_php_url_constant_to_key( $constant ) {
+	$translation = array(
+		PHP_URL_SCHEME   => 'scheme',
+		PHP_URL_HOST     => 'host',
+		PHP_URL_PORT     => 'port',
+		PHP_URL_USER     => 'user',
+		PHP_URL_PASS     => 'pass',
+		PHP_URL_PATH     => 'path',
+		PHP_URL_QUERY    => 'query',
+		PHP_URL_FRAGMENT => 'fragment',
+	);
+
+	if ( isset( $translation[ $constant ] ) ) {
+		return $translation[ $constant ];
+	} else {
+		return false;
+	}
+}