[client] Make MapHelper null safe and do lectureCache refresh with QuickTimer after deleting image.

1 files changed, 8 insertions, 1 deletions

diff --git a/dozentenmodul/src/main/java/org/openslx/dozmod/util/MapHelper.java b/dozentenmodul/src/main/java/org/openslx/dozmod/util/MapHelper.java
index e99b1aa6..487a9ac6 100644
--- a/dozentenmodul/src/main/java/org/openslx/dozmod/util/MapHelper.java
+++ b/dozentenmodul/src/main/java/org/openslx/dozmod/util/MapHelper.java
@@ -11,9 +11,14 @@ public class MapHelper {
 
 	private static final Logger LOGGER = Logger.getLogger(MapHelper.class);
 
-	private MapHelper() {}
+	private MapHelper() {
+	}
 
 	public static <T> boolean hasChanged(final Map<String, T> oldMap, final Map<String, T> newMap) {
+		if (oldMap == null && newMap == null)
+			return false;
+		if ((oldMap == null && newMap != null) || (oldMap != null && newMap == null))
+			return true;
 		// build list of users that were added, if any return true
 		if (oldMap.size() != newMap.size())
 			return true;
@@ -28,11 +33,13 @@ public class MapHelper {
 		// everything was the same if we are still here
 		return false;
 	}
+
 	private static <T> Set<String> getAddedUsers(final Map<String, T> oldMap, final Map<String, T> newMap) {
 		Set<String> addedUsers = new HashSet<String>(newMap.keySet());
 		addedUsers.removeAll(oldMap.keySet());
 		return addedUsers;
 	}
+
 	private static <T> Set<String> getRemovedUsers(final Map<String, T> oldMap, final Map<String, T> newMap) {
 		Set<String> removedUsers = new HashSet<String>(oldMap.keySet());
 		removedUsers.removeAll(newMap.keySet());