[REST] Restore the missing double slash in the ID received by /templates

lib/compat/wordpress-5.9/class-gutenberg-rest-templates-controller.php

@@ -173,9 +173,9 @@ public function get_item_permissions_check( $request ) {
 	 */
 	public function get_item( $request ) {
 		if ( isset( $request['source'] ) && 'theme' === $request['source'] ) {
-			$template = get_block_file_template( $request['id'], $this->post_type );
+			$template = $this->get_template_by_id( $request['id'], true );
 		} else {
-			$template = gutenberg_get_block_template( $request['id'], $this->post_type );
+			$template = $this->get_template_by_id( $request['id'] );
 		}
 
 		if ( ! $template ) {
@@ -202,7 +202,7 @@ public function update_item_permissions_check( $request ) {
 	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
 	 */
 	public function update_item( $request ) {
-		$template = gutenberg_get_block_template( $request['id'], $this->post_type );
+		$template = $this->get_template_by_id( $request['id'] );
 		if ( ! $template ) {
 			return new WP_Error( 'rest_template_not_found', __( 'No templates exist with that id.', 'gutenberg' ), array( 'status' => 404 ) );
 		}
@@ -223,7 +223,7 @@ public function update_item( $request ) {
 			return $result;
 		}
 
-		$template      = gutenberg_get_block_template( $request['id'], $this->post_type );
+		$template      = $this->get_template_by_id( $request['id'] );
 		$fields_update = $this->update_additional_fields_for_object( $template, $request );
 		if ( is_wp_error( $fields_update ) ) {
 			return $fields_update;
@@ -292,7 +292,7 @@ public function delete_item_permissions_check( $request ) {
 	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
 	 */
 	public function delete_item( $request ) {
-		$template = gutenberg_get_block_template( $request['id'], $this->post_type );
+		$template = $this->get_template_by_id( $request['id'] );
 		if ( ! $template ) {
 			return new WP_Error( 'rest_template_not_found', __( 'No templates exist with that id.', 'gutenberg' ), array( 'status' => 404 ) );
 		}
@@ -332,6 +332,61 @@ public function delete_item( $request ) {
 		return $this->prepare_item_for_response( $template, $request );
 	}
 
+	/**
+	 * Requesting this endpoint for a template like "twentytwentytwo//home" requires using
+	 * a path like /wp/v2/templates/twentytwentytwo//home. There are special cases when
+	 * WordPress routing corrects the name to contain only a single slash like "twentytwentytwo/home".
+	 *
+	 * This method attempts to find a template with a specific ID, and if it's missing then it
+	 * falls back to parsing REQUEST_URI in an attempt to grab the verbatim ID passed by the user.
+	 *
+	 * See https://core.trac.wordpress.org/ticket/54507 for more context
+	 *
+	 * @param string  $id        ID of the template.
+	 * @param boolean $from_file Optional Whether to use gutenberg_get_block_template instead of get_block_file_template.
+	 * @return WP_Block_Template|null Template.
+	 */
+	private function get_template_by_id( $id, $from_file = false ) {
+		$getter   = $from_file ? 'get_block_file_template' : 'gutenberg_get_block_template';
+		$template = $getter( $id, $this->post_type );
+		if ( ! $template ) {
+			// Make sure REQUEST_URI is set.
+			if ( empty( $_SERVER['REQUEST_URI'] ) ) {
+				return;
+			}
+
+			$uri       = $_SERVER['REQUEST_URI'];
+			$delimiter = $this->namespace . '/' . $this->rest_base . '/';
+
+			// Extract the part of the path that comes after /wp/v2/templates/.
+			$start = strpos( $uri, $delimiter );
+			if ( false === $start ) {
+				return;
+			}
+			$inferred_id = substr( $uri, $start + strlen( $delimiter ) );
+
+			// Only use part of the path until the first querystring-like symbol (either ? or &).
+			$parts = preg_split( '|[?&]|', $inferred_id );
+			if ( ! $parts ) {
+				return;
+			}
+			$inferred_id = $parts[0];
+
+			// Remove any trailing slashes.
+			$inferred_id = rtrim( $inferred_id, '/' );
+
+			// Halt if the parsed string differs from original one in more than just the number of slashes.
+			// This prevents any creative inputs that wouldn't otherwise be used.
+			if ( str_replace( '/', '', $id ) === str_replace( '/', '', $inferred_id ) ) {
+				return;
+			}
+
+			// Get the template.
+			$template = $getter( $inferred_id, $this->post_type );
+		}
+		return $template;
+	}
+
 	/**
 	 * Prepares a single template for create or update.
 	 *

phpunit/class-gutenberg-rest-template-controller-test.php

@@ -160,6 +160,44 @@ public function test_get_item() {
 		);
 	}
 
+	/**
+	 * Ticket 54507
+	 */
+	public function test_get_item_works_with_a_single_slash() {
+		wp_set_current_user( self::$admin_id );
+		$request = new WP_REST_Request( 'GET', '/wp/v2/templates/tt1-blocks/index' );
+		$old_uri = $_SERVER['REQUEST_URI'];
+
+		$_SERVER['REQUEST_URI'] = '/index.php/wp-json/wp/v2/templates/tt1-blocks//index/?context=edit&_locale=user';
+
+		$response = rest_get_server()->dispatch( $request );
+
+		$_SERVER['REQUEST_URI'] = $old_uri;
+
+		$data = $response->get_data();
+		unset( $data['content'] );
+		unset( $data['_links'] );
+
+		$this->assertEquals(
+			array(
+				'id'             => 'tt1-blocks//index',
+				'theme'          => 'tt1-blocks',
+				'slug'           => 'index',
+				'title'          => array(
+					'raw'      => 'Index',
+					'rendered' => 'Index',
+				),
+				'description'    => 'The default template used when no other template is available. This is a required template in WordPress.',
+				'status'         => 'publish',
+				'source'         => 'theme',
+				'type'           => 'wp_template',
+				'wp_id'          => null,
+				'has_theme_file' => true,
+			),
+			$data
+		);
+	}
+
 	public function test_create_item() {
 		wp_set_current_user( self::$admin_id );
 		$request = new WP_REST_Request( 'POST', '/wp/v2/templates' );