Merge remote-tracking branch 'origin/maven/fixes/8.1' into maven/rele…

…ase/8.1

Backend/services/core/src/main/java/org/edu_sharing/service/nodeservice/NodeServiceImpl.java

@@ -713,6 +713,10 @@ public void updateNodeNative(StoreRef store, String nodeId, Map<String, ?> _prop
 					(m,entry)-> m.put(QName.createQName(entry.getKey()), (Serializable) entry.getValue()),
 					HashMap::putAll
 			);
+
+			// check that no interceptor has set a previously null variable
+			propsNull.removeIf(prop -> propsStore.get(prop) != null);
+
 			nodeService.setProperties(nodeRef, propsStore);
 			// do in transaction to disable behaviour
 			// otherwise interceptors might be called multiple times -> the final update props is enough!