Ticket #43177: 43177.2.patch

src/wp-admin/includes/ajax-actions.php

@@ -1146 +1146 @@
                 wp_die( __( 'Sorry, you must be logged in to reply to a comment.' ) );
         }
 
-        if ( '' == $comment_content ) {
+        if ( '' === trim( $comment_content ) ) {
                 wp_die( __( 'ERROR: please type a comment.' ) );
         }
 

src/wp-includes/class-wp-xmlrpc-server.php

@@ -3719 +3719 @@
 
                 if ( isset( $content_struct['content'] ) ) {
                         $comment_content = $content_struct['content'];
+
+                        if ( '' === trim( $comment_content ) ) {
+                                return new IXR_Error( 403, __( 'Invalid comment content.' ) );
+                        }
                 }
 
                 if ( isset( $content_struct['author'] ) ) {
@@ -3823 +3827 @@
                         return new IXR_Error( 403, __( 'Sorry, comments are closed for this item.' ) );
                 }
 
-                if ( empty( $content_struct['content'] ) ) {
+                if ( empty( $content_struct['content'] ) || '' === trim( $content_struct['content'] ) ) {
                         return new IXR_Error( 403, __( 'Comment is required.' ) );
                 }
 

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

@@ -504 +504 @@
                  * Do not allow a comment to be created with missing or empty
                  * comment_content. See wp_handle_comment_submission().
                  */
-                if ( empty( $prepared_comment['comment_content'] ) ) {
+                if ( empty( $prepared_comment['comment_content'] ) || '' === trim( $prepared_comment['comment_content'] ) ) {
                         return new WP_Error( 'rest_comment_content_invalid', __( 'Invalid comment content.' ), array( 'status' => 400 ) );
                 }
 
@@ -707 +707 @@
                                 return $prepared_args;
                         }
 
-                        if ( isset( $prepared_args['comment_content'] ) && empty( $prepared_args['comment_content'] ) ) {
+                        if ( isset( $prepared_args['comment_content'] ) && '' === trim( $prepared_args['comment_content'] ) ) {
                                 return new WP_Error( 'rest_comment_content_invalid', __( 'Invalid comment content.' ), array( 'status' => 400 ) );
                         }