OO-716, OO-936: fix RS by NullPointerException

src/main/java/org/olat/course/nodes/cl/ui/CheckListRunController.java

@@ -270,8 +270,12 @@ public class CheckListRunController extends FormBasicController implements Contr
 			theOne = wrapper.getDbCheckbox();
 		}
 
-
-		Float score = checked ? wrapper.getCheckbox().getPoints() : 0f;
+		Float score;
+		if(checked) {
+			score = wrapper.getCheckbox().getPoints();
+		} else {
+			score = 0f;
+		}
 		checkboxManager.check(theOne, getIdentity(), score, new Boolean(checked));
 		//make sure all results is on the database before calculating some scores
 		//manager commit already DBFactory.getInstance().commit();

src/main/java/org/olat/ims/qti/statistics/manager/QTIStatisticsManagerImpl.java

@@ -22,6 +22,7 @@ package org.olat.ims.qti.statistics.manager;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -488,7 +489,7 @@ public class QTIStatisticsManagerImpl implements QTIStatisticsManager {
 		List<Object[]> results = query.getResultList();
 		
 		if(results.isEmpty()) {
-			return null;
+			return Collections.emptyList();
 		}
 
 		List<StatisticAnswerOption> answerToNumberList = new ArrayList<>();
@@ -516,7 +517,7 @@ public class QTIStatisticsManagerImpl implements QTIStatisticsManager {
 		List<Object[]> results = query.getResultList();
 		
 		if(results.isEmpty()) {
-			return null;
+			return  Collections.emptyList();
 		}
 		
 		Map<String, Item> identToItemMap = new HashMap<>();