From 8ae679d075f32a48148250f74025799b03e92118 Mon Sep 17 00:00:00 2001
From: pietervdvn <pietervdvn@posteo.net>
Date: Mon, 28 Feb 2022 20:21:37 +0100
Subject: [PATCH] Fix generateLayerOverviews

---
 Models/ThemeConfig/Conversion/Conversion.ts   | 6 +++---
 Models/ThemeConfig/Conversion/PrepareLayer.ts | 4 ++++
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/Models/ThemeConfig/Conversion/Conversion.ts b/Models/ThemeConfig/Conversion/Conversion.ts
index 6d93c0158d..bce74f5ebd 100644
--- a/Models/ThemeConfig/Conversion/Conversion.ts
+++ b/Models/ThemeConfig/Conversion/Conversion.ts
@@ -38,8 +38,8 @@ export abstract class Conversion<TIn, TOut> {
     abstract convert(json: TIn, context: string): { result: TOut, errors?: string[], warnings?: string[], information?: string[] }
 
     public convertAll(jsons: TIn[], context: string): { result: TOut[], errors: string[], warnings: string[], information?: string[] } {
-        if(jsons === undefined){
-            throw "convertAll received undefined - don't do this (at "+context+")"
+        if(jsons === undefined || jsons === null){
+            throw "convertAll received undefined or null - don't do this (at "+context+")"
         }
         const result = []
         const errors = []
@@ -105,7 +105,7 @@ export class OnEveryConcat<X, T> extends DesugaringStep<T> {
         const step = this.step
         const key = this.key;
         const values = json[key]
-        if (values === undefined) {
+        if (values === undefined || values === null) {
             // Move on - nothing to see here!
             return {
                 result: json,
diff --git a/Models/ThemeConfig/Conversion/PrepareLayer.ts b/Models/ThemeConfig/Conversion/PrepareLayer.ts
index 9e75fb8021..82ced05b5a 100644
--- a/Models/ThemeConfig/Conversion/PrepareLayer.ts
+++ b/Models/ThemeConfig/Conversion/PrepareLayer.ts
@@ -307,6 +307,10 @@ class ExpandRewrite<T> extends Conversion<T | RewritableConfigJson<T>, T[]> {
 
     convert(json: T | RewritableConfigJson<T>, context: string): { result: T[]; errors?: string[]; warnings?: string[]; information?: string[] } {
 
+        if(json === null || json === undefined){
+            return {result: []}
+        }
+        
         if (json["rewrite"] === undefined) {
             
             // not a rewrite