REST API, Media: Add `X-WP-Upload-Attachment-ID` HTTP header to enable retrying of post-processing of edited images if the server runs out of resources. This is the same as after uploading a new image, will do up to five additional requests to let the server create all image sub-sizes.

Fixes #50711.
Built from https://develop.svn.wordpress.org/trunk@48525


git-svn-id: http://core.svn.wordpress.org/trunk@48287 1a063a9b-81f0-0310-95a4-ce76da25c4cd

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

@@ -581,6 +581,12 @@ class WP_REST_Attachments_Controller extends WP_REST_Posts_Controller {
 			update_post_meta( $new_attachment_id, '_wp_attachment_image_alt', wp_slash( $image_alt ) );
 		}
 
+		if ( defined( 'REST_REQUEST' ) && REST_REQUEST ) {
+			// Set a custom header with the attachment_id.
+			// Used by the browser/client to resume creating image sub-sizes after a PHP fatal error.
+			header( 'X-WP-Upload-Attachment-ID: ' . $new_attachment_id );
+		}
+
 		// Generate image sub-sizes and meta.
 		$new_image_meta = wp_generate_attachment_metadata( $new_attachment_id, $saved['path'] );
 

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.5-beta2-48524';
+$wp_version = '5.5-beta2-48525';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.