OO-1242: row can be null in the list of objects if someone jump a page

src/main/java/org/olat/repository/ui/list/RepositoryEntryListController.java

@@ -355,7 +355,7 @@ public class RepositoryEntryListController extends FormBasicController
 						Long rowKey = new Long(rowKeyStr);
 						List<RepositoryEntryRow> rows = model.getObjects();
 						for(RepositoryEntryRow row:rows) {
-							if(row.getKey().equals(rowKey)) {
+							if(row != null && row.getKey().equals(rowKey)) {
 								if (row.isMember()) {
 									doOpen(ureq, row);					
 								} else {