OO-2128: don't copy missing rules (patch S. Clemenz)

src/main/java/org/olat/modules/reminder/manager/ReminderServiceImpl.java

@@ -116,7 +116,7 @@ public class ReminderServiceImpl implements ReminderService {
 		if(StringHelper.containsNonWhitespace(configuration)) {
 			ReminderRules rules = toRules(configuration);
 			for(ReminderRule rule:rules.getRules()) {
-				if(ReminderRuleEngine.DATE_RULE_TYPE.equals(rule.getType()) && rule instanceof ReminderRuleImpl) {
+				if(rule instanceof ReminderRuleImpl && ReminderRuleEngine.DATE_RULE_TYPE.equals(rule.getType())) {
 					ReminderRuleImpl r = (ReminderRuleImpl)rule;
 					if(DateRuleSPI.AFTER.equals(r.getOperator()) && StringHelper.containsNonWhitespace(r.getRightOperand())) {
 						try {

src/main/java/org/olat/repository/handlers/CourseHandler.java

@@ -443,7 +443,8 @@ public class CourseHandler implements RepositoryHandler {
 				RuleSPI ruleSpi = reminderModule.getRuleSPIByType(rule.getType());
 				if(ruleSpi != null) {
 					ReminderRule clonedRule = ruleSpi.clone(rule, envMapper);
-					clonedRules.getRules().add(clonedRule);
+					if (clonedRule != null) 
+						clonedRules.getRules().add(clonedRule);
 				}
 			}