Ticket #3799: duplicate-category-protection.diff

C:/xampp/htdocs/wordpress/trunk/wp-admin/admin-ajax.php

@@ -246 +246 @@
                 $x->send();
         }
 
+        if ( category_exists( trim( $_POST['cat_name'] ) ) ) {
+                $x = new WP_Ajax_Response( array(
+                        'what' => 'cat',
+                        'id' => new WP_Error( 'cat_exists', __('The category you are trying to create already exists.') )
+                ) );
+                $x->send();
+        }
+        
         $cat = wp_insert_category( $_POST, true );
 
         if ( is_wp_error($cat) ) {