Apply suggestions from code review

Co-authored-by: Weston Ruter <westonruter@gmail.com>

Author: adamsilverstein

src/wp-includes/media.php

@@ -6638,8 +6638,8 @@ function wp_add_crossorigin_attributes( string $html ): string {
 				$srcset = $processor->get_attribute( $attr );
 				if ( is_string( $srcset ) ) {
 					foreach ( explode( ',', $srcset ) as $candidate ) {
-						$candidate_url = strtok( trim( $candidate ), ' ' );
-						if ( is_string( $candidate_url ) && '' !== $candidate_url && ! str_starts_with( $candidate_url, $site_url ) && ! str_starts_with( $candidate_url, '/' ) ) {
+						$candidate_url = strtok( trim( $candidate, " \t\f\r\n" ), " \t\f\r\n" );
+						if ( is_string( $candidate_url ) && ! str_starts_with( $candidate_url, $site_url ) && ! str_starts_with( $candidate_url, '/' ) ) {
 							$is_cross_origin = true;
 							break;
 						}

src/wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php

@@ -415,7 +415,7 @@ public function create_item( $request ) {
 	 *
 	 * @since 7.0.0
 	 */
-	private function remove_client_side_media_processing_filters() {
+	private function remove_client_side_media_processing_filters(): void {
 		remove_filter( 'intermediate_image_sizes_advanced', '__return_empty_array', 100 );
 		remove_filter( 'fallback_intermediate_image_sizes', '__return_empty_array', 100 );
 		remove_filter( 'wp_image_maybe_exif_rotate', '__return_false', 100 );
@@ -2012,7 +2012,7 @@ public function sideload_item_permissions_check( $request ) {
 	 * @return WP_REST_Response|WP_Error Response object on success, WP_Error object on failure.
 	 */
 	public function sideload_item( WP_REST_Request $request ) {
-		$attachment_id = $request['id'];
+		$attachment_id = (int) $request['id'];
 
 		$post = $this->get_post( $attachment_id );
 
@@ -2225,7 +2225,7 @@ private static function filter_wp_unique_filename( $filename, $dir, $number, $at
 	 * @return WP_REST_Response|WP_Error Response object on success, WP_Error object on failure.
 	 */
 	public function finalize_item( WP_REST_Request $request ) {
-		$attachment_id = $request['id'];
+		$attachment_id = (int) $request['id'];
 
 		$post = $this->get_post( $attachment_id );
 		if ( is_wp_error( $post ) ) {