REST API: Allow shortcircuiting rest_pre_insert_comment

rest_pre_insert_{post_type} allows returning a WP_Error from the filter to shortcircuit actually creating the object, so it makes sense to do so for comments too.

Props dspilka.
Fixes #39578.

Built from https://develop.svn.wordpress.org/trunk@39922


git-svn-id: http://core.svn.wordpress.org/trunk@39859 1a063a9b-81f0-0310-95a4-ce76da25c4cd

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

@@ -552,13 +552,19 @@ class WP_REST_Comments_Controller extends WP_REST_Controller {
 		 * Filters a comment before it is inserted via the REST API.
 		 *
 		 * Allows modification of the comment right before it is inserted via wp_insert_comment().
+		 * Returning a WP_Error value from the filter will shortcircuit insertion and allow
+		 * skipping further processing.
 		 *
 		 * @since 4.7.0
+		 * @since 4.8.0 $prepared_comment can now be a WP_Error to shortcircuit insertion.
 		 *
-		 * @param array           $prepared_comment The prepared comment data for wp_insert_comment().
+		 * @param array|WP_Error  $prepared_comment The prepared comment data for wp_insert_comment().
 		 * @param WP_REST_Request $request          Request used to insert the comment.
 		 */
 		$prepared_comment = apply_filters( 'rest_pre_insert_comment', $prepared_comment, $request );
+		if ( is_wp_error( $prepared_comment ) ) {
+			return $prepared_comment;
+		}
 
 		$comment_id = wp_insert_comment( wp_filter_comment( wp_slash( (array) $prepared_comment ) ) );
 

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.8-alpha-39921';
+$wp_version = '4.8-alpha-39922';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.