OO-4869: filter deleted users from QTI 2.1 results export

src/main/java/org/olat/core/util/StringHelper.java

@@ -475,6 +475,8 @@ public class StringHelper {
 	 * @return transformed string
 	 */
 	public static String transformDisplayNameToFileSystemName(String s){
+		if(s == null) return "";
+		
 		//replace some separator with an underscore
 		s = s.replace('?', '_').replace('\\', '_').replace('/', '_').replace(' ', '_');
 		//remove all non-ascii characters

src/main/java/org/olat/ims/qti21/resultexport/QTI21ResultsExportMediaResource.java

@@ -279,6 +279,10 @@ public class QTI21ResultsExportMediaResource implements MediaResource {
 
 		List<AssessedMember> assessedMembers = new ArrayList<>();		
 		for(Identity identity : identities) {
+			if(identity == null || identity.getStatus() == null || identity.getStatus().equals(Identity.STATUS_DELETED)) {
+				continue;
+			}
+			
 			String lastname = StringHelper.transformDisplayNameToFileSystemName(identity.getUser().getLastName());
 			String idDir = exportFolderName + "/" + DATA + lastname + "_" + identity.getKey();
 			idDir = idDir.endsWith(SEP) ? idDir : idDir + SEP;

src/test/java/org/olat/core/util/StringHelperTest.java

@@ -91,6 +91,11 @@ public class StringHelperTest {
 		Assert.assertEquals("Webclaess", StringHelper.transformDisplayNameToFileSystemName("Webcl\u00E4ss"));
 	}
 	
+	@Test
+	public void transformDisplayNameToFileSystemNameNull() {
+		Assert.assertEquals("", StringHelper.transformDisplayNameToFileSystemName(null));
+	}
+	
 	@Test
 	public void filterPrintControlCharacter() {
 		String value1 = StringHelper.cleanUTF8ForXml("Hello world");