Ticket #28488: post.php.diff

src/wp-includes/post.php

@@ -2185 +2185 @@
         $cache_key = 'posts-' . $type;
         if ( 'readable' == $perm && is_user_logged_in() ) {
                 $post_type_object = get_post_type_object( $type );
-                if ( ! current_user_can( $post_type_object->cap->read_private_posts ) ) {
+                if ( null !== $post_type_object && !current_user_can( $post_type_object->cap->read_private_posts ) ) {
                         $cache_key .= '_' . $perm . '_' . get_current_user_id();
                 }
         }