REST API: Persist attributes for attachment links

In [43437], the link definition implementation caused attachment links to be unexpectedly nested under an attributes key. This changeset restores the prior behavior.

Merges [43681] to trunk.

Props TimothyBlynJacobs, danielbachhuber.
Fixes #44750.


git-svn-id: https://develop.svn.wordpress.org/trunk@43973 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/media-template.php

@@ -96,7 +96,7 @@ function wp_underscore_video_template() {
 	<# if ( w ) { #>width="{{ w }}"<# } #>
 	<# if ( h ) { #>height="{{ h }}"<# } #>
 	<?php
-	$props = array(
+	$props       = array(
 		'poster'  => '',
 		'preload' => 'metadata',
 	);

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

@@ -375,7 +375,12 @@ class WP_REST_Attachments_Controller extends WP_REST_Posts_Controller {
 
 		// Wrap the data in a response object.
 		$response = rest_ensure_response( $data );
-		$response->add_links( $links );
+
+		foreach ( $links as $rel => $rel_links ) {
+			foreach ( $rel_links as $link ) {
+				$response->add_link( $rel, $link['href'], $link['attributes'] );
+			}
+		}
 
 		/**
 		 * Filters an attachment returned from the REST API.