Docs: Replace void with null in union return types in Customize

src/wp-includes/class-wp-customize-manager.php

@@ -3863,7 +3863,7 @@ public function add_dynamic_settings( $setting_ids ) {
 	 * @since 3.4.0
 	 *
 	 * @param string $id Customize Setting ID.
-	 * @return WP_Customize_Setting|void The setting, if set.
+	 * @return WP_Customize_Setting|null The setting, if set.
 	 */
 	public function get_setting( $id ) {
 		if ( isset( $this->settings[ $id ] ) ) {
@@ -3915,7 +3915,7 @@ public function add_panel( $id, $args = array() ) {
 	 * @since 4.0.0
 	 *
 	 * @param string $id Panel ID to get.
-	 * @return WP_Customize_Panel|void Requested panel instance, if set.
+	 * @return WP_Customize_Panel|null Requested panel instance, if set.
 	 */
 	public function get_panel( $id ) {
 		if ( isset( $this->panels[ $id ] ) ) {
@@ -4011,7 +4011,7 @@ public function add_section( $id, $args = array() ) {
 	 * @since 3.4.0
 	 *
 	 * @param string $id Section ID.
-	 * @return WP_Customize_Section|void The section, if set.
+	 * @return WP_Customize_Section|null The section, if set.
 	 */
 	public function get_section( $id ) {
 		if ( isset( $this->sections[ $id ] ) ) {
@@ -4090,7 +4090,7 @@ public function add_control( $id, $args = array() ) {
 	 * @since 3.4.0
 	 *
 	 * @param string $id ID of the control.
-	 * @return WP_Customize_Control|void The control object, if set.
+	 * @return WP_Customize_Control|null The control object, if set.
 	 */
 	public function get_control( $id ) {
 		if ( isset( $this->controls[ $id ] ) ) {

src/wp-includes/class-wp-customize-setting.php

@@ -856,15 +856,15 @@ final public function check_capabilities() {
 	 * @param array $root
 	 * @param array $keys
 	 * @param bool  $create Default false.
-	 * @return array|void Keys are 'root', 'node', and 'key'.
+	 * @return array|null Keys are 'root', 'node', and 'key'.
 	 */
 	final protected function multidimensional( &$root, $keys, $create = false ) {
 		if ( $create && empty( $root ) ) {
 			$root = array();
 		}
 
 		if ( ! isset( $root ) || empty( $keys ) ) {
-			return;
+			return null;
 		}
 
 		$last = array_pop( $keys );
@@ -876,7 +876,7 @@ final protected function multidimensional( &$root, $keys, $create = false ) {
 			}
 
 			if ( ! is_array( $node ) || ! isset( $node[ $key ] ) ) {
-				return;
+				return null;
 			}
 
 			$node = &$node[ $key ];
@@ -893,7 +893,7 @@ final protected function multidimensional( &$root, $keys, $create = false ) {
 		}
 
 		if ( ! isset( $node[ $last ] ) ) {
-			return;
+			return null;
 		}
 
 		return array(

src/wp-includes/class-wp-customize-widgets.php

@@ -176,7 +176,7 @@ public function is_widget_selective_refreshable( $id_base ) {
 	 * @since 4.2.0
 	 *
 	 * @param string $setting_id Setting ID.
-	 * @return string|void Setting type.
+	 * @return string|null Setting type.
 	 */
 	protected function get_setting_type( $setting_id ) {
 		static $cache = array();
@@ -1454,7 +1454,7 @@ protected function get_instance_hash_key( $serialized_instance ) {
 	 *
 	 * @param array  $value   Widget instance to sanitize.
 	 * @param string $id_base Optional. Base of the ID of the widget being sanitized. Default null.
-	 * @return array|void Sanitized widget instance.
+	 * @return array|null Sanitized widget instance.
 	 */
 	public function sanitize_widget_instance( $value, $id_base = null ) {
 		global $wp_widget_factory;
@@ -1483,21 +1483,21 @@ public function sanitize_widget_instance( $value, $id_base = null ) {
 			empty( $value['instance_hash_key'] ) ||
 			empty( $value['encoded_serialized_instance'] )
 		) {
-			return;
+			return null;
 		}
 
 		$decoded = base64_decode( $value['encoded_serialized_instance'], true );
 		if ( false === $decoded ) {
-			return;
+			return null;
 		}
 
 		if ( ! hash_equals( $this->get_instance_hash_key( $decoded ), $value['instance_hash_key'] ) ) {
-			return;
+			return null;
 		}
 
 		$instance = unserialize( $decoded );
 		if ( false === $instance ) {
-			return;
+			return null;
 		}
 
 		return $instance;

src/wp-includes/customize/class-wp-customize-header-image-control.php

@@ -193,7 +193,7 @@ public function print_header_image_template() {
 	 *
 	 * @since 3.9.0
 	 *
-	 * @return string|void
+	 * @return string|null
 	 */
 	public function get_current_image_src() {
 		$src = $this->value();