⏫ Forwardport of #11240 to 2.3-develop branch

Applied pull request patch https://github.com/magento/magento2/pull/11240.patch (created by @leptoquark1) based on commit(s): 1. 16a8050 2. 86032de
magento · Jan 23, 2018 · 6d4f36d · 6d4f36d
1 parent 8e77e2f
commit 6d4f36d
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/lib/internal/Magento/Framework/View/Model/Layout/Merge.php b/lib/internal/Magento/Framework/View/Model/Layout/Merge.php
@@ -811,7 +811,7 @@ private function getXmlErrors($libXmlErrors)
     protected function _getPhysicalTheme(\Magento\Framework\View\Design\ThemeInterface $theme)
     {
         $result = $theme;
-        while ($result->getId() && !$result->isPhysical()) {
+        while ($result !== null && $result->getId() && !$result->isPhysical()) {
             $result = $result->getParentTheme();
         }
         if (!$result) {