OO-2480: node attempts must return a value, default is zero

src/main/java/org/olat/course/assessment/manager/CourseAssessmentManagerImpl.java

@@ -388,7 +388,7 @@ public class CourseAssessmentManagerImpl implements AssessmentManager {
 		
 		AssessmentEntry nodeAssessment = assessmentService
 				.loadAssessmentEntry(identity, cgm.getCourseEntry(), courseNode.getIdent());	
-		return nodeAssessment == null ? INTEGER_ZERO : nodeAssessment.getAttempts();
+		return nodeAssessment == null || nodeAssessment.getAttempts() == null  ? INTEGER_ZERO : nodeAssessment.getAttempts();
 	}
 
 	@Override

src/main/java/org/olat/course/nodes/iq/IQRunController.java

@@ -610,7 +610,7 @@ public class IQRunController extends BasicController implements GenericEventList
 	    		myContent.contextPut("passed", assessmentEntry.getPassed());
 	    		StringBuilder comment = Formatter.stripTabsAndReturns(assessmentEntry.getComment());
 	    		myContent.contextPut("comment", StringHelper.xssScan(comment));
-	    		myContent.contextPut("attempts", assessmentEntry.getAttempts());
+	    		myContent.contextPut("attempts", assessmentEntry.getAttempts() == null ? 0 : assessmentEntry.getAttempts());
     		}
     	}