From 91e200064f93a602044d279111567be74b2a365a Mon Sep 17 00:00:00 2001
From: Matthias Schmidt <gravatronics@live.com>
Date: Thu, 24 Jan 2019 18:24:07 +0100
Subject: [PATCH] Fix exception when reading value of field without
 immutability support

See #2509
See aa6f853584182980c1c7d12891b689317e458b8b
---
 .../files/lib/system/form/builder/TFormParentNode.class.php    | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/wcfsetup/install/files/lib/system/form/builder/TFormParentNode.class.php b/wcfsetup/install/files/lib/system/form/builder/TFormParentNode.class.php
index b581866e42..c9fa7b8fed 100644
--- a/wcfsetup/install/files/lib/system/form/builder/TFormParentNode.class.php
+++ b/wcfsetup/install/files/lib/system/form/builder/TFormParentNode.class.php
@@ -1,6 +1,7 @@
 <?php
 namespace wcf\system\form\builder;
 use wcf\system\form\builder\field\IFormField;
+use wcf\system\form\builder\field\IImmutableFormField;
 
 /**
  * Provides default implementations of `IFormParentNode` methods.
@@ -271,7 +272,7 @@ trait TFormParentNode {
 				if ($child instanceof IFormParentNode) {
 					$child->readValues();
 				}
-				else if ($child instanceof IFormField && $child->isAvailable() && !$child->isImmutable()) {
+				else if ($child instanceof IFormField && $child->isAvailable() && (!($child instanceof IImmutableFormField) || !$child->isImmutable())) {
 					$child->readValue();
 				}
 			}
-- 
2.20.1