1 files changed, 9 insertions, 3 deletions

diff --git a/model-data/src/main/java/org/eclipse/viatra/solver/data/map/internal/MapDiffCursor.java b/model-data/src/main/java/org/eclipse/viatra/solver/data/map/internal/MapDiffCursor.java
index 9e3a47ab..e97e4aa1 100644
--- a/model-data/src/main/java/org/eclipse/viatra/solver/data/map/internal/MapDiffCursor.java
+++ b/model-data/src/main/java/org/eclipse/viatra/solver/data/map/internal/MapDiffCursor.java
@@ -51,13 +51,15 @@ public class MapDiffCursor<K,V> implements DiffCursor<K, V>, Cursor<K,V>{
                 this.cursor1 = (MapCursor<K, V>) cursor1;
                 this.cursor2 = (MapCursor<K, V>) cursor2;
         }
-
+        @Override
         public K getKey() {
                 return key;
         }
+        @Override
         public V getFromValue() {
                 return fromValue;
         }
+        @Override
         public V getToValue() {
                 return toValue;
         }
@@ -73,7 +75,7 @@ public class MapDiffCursor<K,V> implements DiffCursor<K, V>, Cursor<K,V>{
                 return this.cursor1.isDirty() || this.cursor2.isDirty();
         }
         @Override
-        public List<VersionedMap<K, V>> getDependingMaps() {
+        public List<VersionedMap<?, ?>> getDependingMaps() {
                 return Stream.concat(
                                 cursor1.getDependingMaps().stream(),
                                 cursor2.getDependingMaps().stream()
@@ -142,7 +144,11 @@ public class MapDiffCursor<K,V> implements DiffCursor<K, V>, Cursor<K,V>{
 
         
         protected boolean sameValues() {
-                return this.fromValue == this.toValue;
+                if(this.fromValue == null) {
+                        return this.toValue == null;
+                } else {
+                        return this.fromValue.equals(this.toValue);
+                }
         }
         protected boolean moveOne() {
                 if(isTerminated()) {