From a6c094f9aaad11ab6cff8e9df52323b356bfe5fb Mon Sep 17 00:00:00 2001
From: Andy Miller <rhuk@mac.com>
Date: Thu, 13 Aug 2020 11:43:55 -0600
Subject: [PATCH] fix error when no parent exists

Signed-off-by: Andy Miller <rhuk@mac.com>
---
 system/src/Grav/Common/Twig/TwigExtension.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/system/src/Grav/Common/Twig/TwigExtension.php b/system/src/Grav/Common/Twig/TwigExtension.php
index 46af147a5..a0aada5e8 100644
--- a/system/src/Grav/Common/Twig/TwigExtension.php
+++ b/system/src/Grav/Common/Twig/TwigExtension.php
@@ -1344,7 +1344,7 @@ class TwigExtension extends AbstractExtension implements GlobalsInterface
         // Try to find var in the page headers
         if ($page instanceof PageInterface && $page->exists()) {
             // Loop over pages and look for header vars
-            while (!$page->root()) {
+            while ($page && !$page->root()) {
                 $header = new Data((array)$page->header());
                 $value = $header->get($var);
                 if (isset($value)) {