From 744cf1aef6789443a669f9f2a6ce73b43ac3c2cf Mon Sep 17 00:00:00 2001
From: Markus <1720843+maxmarkus@users.noreply.github.com>
Date: Thu, 21 Nov 2019 14:51:49 +0100
Subject: [PATCH] Bugfix invalid initial root navnode (#979)

---
 core/src/utilities/helpers/routing-helpers.js | 12 ++++++++-
 docs/navigation-parameters-reference.md       | 25 +++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/core/src/utilities/helpers/routing-helpers.js b/core/src/utilities/helpers/routing-helpers.js
index 836c46a516..390ee12b38 100644
--- a/core/src/utilities/helpers/routing-helpers.js
+++ b/core/src/utilities/helpers/routing-helpers.js
@@ -30,7 +30,17 @@ class RoutingHelpersClass {
       return lastElement.defaultChildNode;
     } else if (children && children.length) {
       const rootPath = pathData.navigationPath.length === 1;
-      if (rootPath) return children[0].pathSegment;
+      if (rootPath) {
+        const firstNodeWithPathSegment = children.find(
+          child => child.pathSegment
+        );
+        return (
+          (firstNodeWithPathSegment && firstNodeWithPathSegment.pathSegment) ||
+          console.error(
+            'At least one navigation node in the root hierarchy must have a pathSegment.'
+          )
+        );
+      }
       const validChild = children.find(
         child =>
           child.pathSegment &&
diff --git a/docs/navigation-parameters-reference.md b/docs/navigation-parameters-reference.md
index b1765a780f..07e78f221a 100644
--- a/docs/navigation-parameters-reference.md
+++ b/docs/navigation-parameters-reference.md
@@ -129,6 +129,31 @@ Node parameters are all the parameters that can be added to an individual naviga
 - **type**: string
 - **description**: sets the child node that Luigi activates automatically if the current node has no **viewUrl** defined. Provide **pathSegment** of the child node you want to activate as a string.
 
+<!-- add-attribute:class:warning -->
+>**NOTE:** To define a root-level **defaultChildNode** which is different than the first header navigation node, set an object with **defaultChildNode** and **children** set to `navigation.nodes` instead of an array of nodes.
+
+- **example**:
+```javascript
+settings: {
+  navigation: {
+    nodes: {
+      defaultChildNode: 'overview',
+      children: [
+        {
+          pathSegment: 'docs',
+          label: 'Documentation',
+          viewUrl: '...'
+        },
+        {
+          pathSegment: 'overview',
+          label: 'Overview',
+          viewUrl: '...'
+        }
+      ]
+    }
+  }
+```
+
 ### isolateView
 - **type**: boolean
 - **description**: renders the view in a new frame when you enter and leave the node. This setting overrides the same-domain frame re-usage. The **isolateView** is disabled by default.