Ticket #21609: 21609.2.patch

wp-includes/comment.php

@@ -669 +669 @@
 
         // Simple duplicate check
         // expected_slashed ($comment_post_ID, $comment_author, $comment_author_email, $comment_content)
-        $dupe = "SELECT comment_ID FROM $wpdb->comments WHERE comment_post_ID = '$comment_post_ID' AND comment_approved != 'trash' AND ( comment_author = '$comment_author' ";
+        $dupe = $wpdb->prepare( "SELECT comment_ID FROM $wpdb->comments WHERE comment_post_ID = %d AND comment_parent = %d AND comment_approved != 'trash' AND ( comment_author = %s ", $comment_post_ID, $comment_parent, $comment_author );
         if ( $comment_author_email )
-                $dupe .= "OR comment_author_email = '$comment_author_email' ";
-        $dupe .= ") AND comment_content = '$comment_content' LIMIT 1";
+                $dupe .= $wpdb->prepare( "OR comment_author_email = %s ", $comment_author_email );
+        $dupe .= $wpdb->prepare( ") AND comment_content = %s LIMIT 1", $comment_content );
         if ( $wpdb->get_var($dupe) ) {
                 do_action( 'comment_duplicate_trigger', $commentdata );
                 if ( defined('DOING_AJAX') )