Filter should receive an array.

joedolson · joedolson · commit aff316bca25f · 2025-10-31T18:07:22.000-05:00
diff --git a/src/wp-includes/general-template.php b/src/wp-includes/general-template.php
@@ -1436,7 +1436,7 @@ function wp_title( $sep = '&raquo;', $display = true, $seplocation = '' ) {
 	 *
 	 * @param string[] $title_array Array of parts of the page title.
 	 */
-	$title_array = apply_filters( 'wp_title_parts', ! empty( $title ) ? explode( $t_sep, $title ) : '' );
+	$title_array = apply_filters( 'wp_title_parts', ! empty( $title ) ? explode( $t_sep, $title ) : array() );
 
 	// Determines position of the separator and direction of the breadcrumb.
 	if ( 'right' === $seplocation ) { // Separator on right, so reverse the order.

Original file line number	Diff line number	Diff line change
`@@ -1436,7 +1436,7 @@ function wp_title( $sep = '»', $display = true, $seplocation = '' ) {`
`1436`	`1436`	`*`
`1437`	`1437`	`* @param string[] $title_array Array of parts of the page title.`
`1438`	`1438`	`*/`
`1439`		`- $title_array = apply_filters( 'wp_title_parts', ! empty( $title ) ? explode( $t_sep, $title ) : '' );`
	`1439`	`+ $title_array = apply_filters( 'wp_title_parts', ! empty( $title ) ? explode( $t_sep, $title ) : array() );`
`1440`	`1440`
`1441`	`1441`	`// Determines position of the separator and direction of the breadcrumb.`
`1442`	`1442`	`if ( 'right' === $seplocation ) { // Separator on right, so reverse the order.`