Media: Add short-circuit filter to `attachment_url_to_postid()`.

Introduces the filter `pre_attachment_url_to_postid` to allow developers to short-circuit the function `attachment_url_to_postid()`.

The return values are expected to be an attachment ID, zero (`0`) to indicate no attachment was found or `null` to indicate the function should proceed as usual.

The function performs an expensive database query so developers making use of the function frequently may wish to use a custom table with appropriate indexes to reduce the load on their database server.

Props antpb, apermo, audrasjb, joedolson.
Fixes #61383.

Built from https://develop.svn.wordpress.org/trunk@59118


git-svn-id: http://core.svn.wordpress.org/trunk@58514 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/media.php

@@ -5383,6 +5383,31 @@ function wp_maybe_generate_attachment_metadata( $attachment ) {
 function attachment_url_to_postid( $url ) {
 	global $wpdb;
 
+	/**
+	 * Filters the attachment ID to allow short-circuit the function.
+	 *
+	 * Allows plugins to short-circuit attachment ID lookups. Plugins making
+	 * use of this function should return:
+	 *
+	 * - 0 (integer) to indicate the attachment is not found,
+	 * - attachment ID (integer) to indicate the attachment ID found,
+	 * - null to indicate WordPress should proceed with the lookup.
+	 *
+	 * Warning: The post ID may be null or zero, both of which cast to a
+	 * boolean false. For information about casting to booleans see the
+	 * {@link https://www.php.net/manual/en/language.types.boolean.php PHP documentation}.
+	 * Use the === operator for testing the post ID when developing filters using
+	 * this hook.
+	 *
+	 * @param int|null $post_id The result of the post ID lookup. Null to indicate
+	 *                          no lookup has been attempted. Default null.
+	 * @param string   $url     The URL being looked up.
+	 */
+	$post_id = apply_filters( 'pre_attachment_url_to_postid', null, $url );
+	if ( null !== $post_id ) {
+		return (int) $post_id;
+	}
+
 	$dir  = wp_get_upload_dir();
 	$path = $url;
 

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.7-alpha-59117';
+$wp_version = '6.7-alpha-59118';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.