From 5764cacfc8a6f3fbf588f04d0d351ccc6c66e9d1 Mon Sep 17 00:00:00 2001
From: Matthias Ronge <matthias.ronge@mik-center.de>
Date: Wed, 21 Feb 2024 10:45:04 +0100
Subject: [PATCH] Prevent saving a broken METS file (#5883)

Throw an illegal argument exception if either side of the pair is null
---
 .../org/kitodo/dataformat/access/MetsXmlElementAccess.java  | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Kitodo-DataFormat/src/main/java/org/kitodo/dataformat/access/MetsXmlElementAccess.java b/Kitodo-DataFormat/src/main/java/org/kitodo/dataformat/access/MetsXmlElementAccess.java
index dc4748b46bd..f27a6fb5642 100644
--- a/Kitodo-DataFormat/src/main/java/org/kitodo/dataformat/access/MetsXmlElementAccess.java
+++ b/Kitodo-DataFormat/src/main/java/org/kitodo/dataformat/access/MetsXmlElementAccess.java
@@ -428,6 +428,12 @@ private DivType generatePhysicalStructMapRecursive(PhysicalDivision physicalDivi
     private StructLink createStructLink(LinkedList<Pair<String, String>> smLinkData) {
         StructLink structLink = new StructLink();
         structLink.getSmLinkOrSmLinkGrp().addAll(smLinkData.parallelStream().map(entry -> {
+            if (Objects.isNull(entry.getLeft())) {
+                throw new IllegalArgumentException("smLinkData.entry[?].left must not be null");
+            }
+            if (Objects.isNull(entry.getRight())) {
+                throw new IllegalArgumentException("smLinkData.entry[?].right must not be null");
+            }
             SmLink smLink = new SmLink();
             smLink.setFrom(entry.getLeft());
             smLink.setTo(entry.getRight());