Ticket #18474: 18474.diff

Index: wp-includes/pluggable.php
===================================================================
--- wp-includes/pluggable.php   (revision 18589)
+++ wp-includes/pluggable.php   (working copy)
@@ -844,6 +844,14 @@
        $adminurl = strtolower(admin_url());
        $referer = strtolower(wp_get_referer());
        $result = isset($_REQUEST[$query_arg]) ? wp_verify_nonce($_REQUEST[$query_arg], $action) : false;
+
+       // Detect errors caused by truncated posts
+       // If the file was uploaded, but exceeds the file upload limit, then it will be handled elsewhere
+       // but if the post was too big, then it won't be decoded properly and the nonce won't come through
+       // so it will be caught here
+       if ( 'POST' == $_SERVER['REQUEST_METHOD'] && empty($_POST) && $_SERVER['CONTENT_LENGTH'] > 0 )
+               wp_die(__( 'The request exceeds the <code>post_max_size</code> directive in <code>php.ini</code>.' ));
+
        if ( !$result && !(-1 == $action && strpos($referer, $adminurl) === 0) ) {
                wp_nonce_ays($action);
                die();