From 42cb0820a27285542d4938e03917f01eefd26eb2 Mon Sep 17 00:00:00 2001
From: Mojmir Fendek <mojmir@silverstripe.com>
Date: Wed, 5 Jul 2017 10:03:10 +1200
Subject: [PATCH] Limits added to collateDescendants() to ensure reasonable
 performance with thousands of pages.

---
 code/Model/SiteTree.php | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/code/Model/SiteTree.php b/code/Model/SiteTree.php
index 55592efb..23878d8d 100755
--- a/code/Model/SiteTree.php
+++ b/code/Model/SiteTree.php
@@ -1256,6 +1256,12 @@ class SiteTree extends DataObject implements PermissionProvider, i18nEntityProvi
      */
     public function collateDescendants($condition, &$collator)
     {
+        // apply reasonable hierarchy limits
+        $threshold = Config::inst()->get(Hierarchy::class, 'node_threshold_leaf');
+        if ($this->numChildren() > $threshold) {
+            return false;
+        }
+
         $children = $this->Children();
         if ($children) {
             foreach ($children as $item) {