Media: Make media library searchable by filename.

This applies a new private function, `_filter_query_attachment_filenames()`,
to the `post_clauses` filter hook during `wp_ajax_query_attachments()` and
`wp_edit_attachments_query_vars()` to include `_wp_attached_file` post meta
in search queries performed from the media library or in a `WP_Media_List_Table`.

Props wonderboymusic, DrewAPicture, joemcgill, swissspidy.
Fixes #22744.
Built from https://develop.svn.wordpress.org/trunk@38625


git-svn-id: http://core.svn.wordpress.org/trunk@38568 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/ajax-actions.php

@@ -2397,6 +2397,9 @@ function wp_ajax_query_attachments() {
 	if ( current_user_can( get_post_type_object( 'attachment' )->cap->read_private_posts ) )
 		$query['post_status'] .= ',private';
 
+	// Filter query clauses to include filenames.
+	add_filter( 'posts_clauses', '_filter_query_attachment_filenames' );
+
 	/**
 	 * Filters the arguments passed to WP_Query during an Ajax
 	 * call for querying attachments.

wp-admin/includes/post.php

@@ -1144,9 +1144,37 @@ function wp_edit_attachments_query_vars( $q = false ) {
 		$q['post_parent'] = 0;
 	}
 
+	// Filter query clauses to include filenames.
+	add_filter( 'posts_clauses', '_filter_query_attachment_filenames' );
+
 	return $q;
 }
 
+/**
+ * Filter the SQL clauses of an attachment query to include filenames.
+ *
+ * @since 4.7.0
+ * @access private
+ *
+ * @param array $clauses An array including WHERE, GROUP BY, JOIN, ORDER BY,
+ *                       DISTINCT, fields (SELECT), and LIMITS clauses.
+ * @return array The modified clauses.
+ */
+function _filter_query_attachment_filenames( $clauses ) {
+	global $wpdb;
+	remove_filter( 'posts_clauses', __FUNCTION__ );
+
+	$clauses['join'] = " INNER JOIN {$wpdb->postmeta} ON ( {$wpdb->posts}.ID = {$wpdb->postmeta}.post_id )";
+	$clauses['groupby'] = "{$wpdb->posts}.ID";
+
+	$clauses['where'] = preg_replace(
+		"/\({$wpdb->posts}.post_content (NOT LIKE|LIKE) (\'[^']+\')\)/",
+		"$0 OR ( {$wpdb->postmeta}.meta_key = '_wp_attached_file' AND {$wpdb->postmeta}.meta_value $1 $2 )",
+		$clauses['where'] );
+
+	return $clauses;
+}
+
 /**
  * Executes a query for attachments. An array of WP_Query arguments
  * can be passed in, which will override the arguments set by this function.

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.7-alpha-38624';
+$wp_version = '4.7-alpha-38625';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.