Don't pass JSONObject.Null as diffstate value (#9026)

diff --git a/server/src/com/vaadin/terminal/gwt/server/JsonCodec.java b/server/src/com/vaadin/terminal/gwt/server/JsonCodec.java
index 884e01f9a5cc69ed303a1d551b8f71012085350c..cb0a604b89f2789541ef1cf4233459781a9cd631 100644 (file)
--- a/server/src/com/vaadin/terminal/gwt/server/JsonCodec.java
+++ b/server/src/com/vaadin/terminal/gwt/server/JsonCodec.java
@@ -624,6 +624,9 @@ public class JsonCodec implements Serializable {
                     diffStateValue = diffState.get(fieldName);
                     Object referenceFieldValue = decodeInternalOrCustomType(
                             fieldType, diffStateValue, connectorTracker);
+                    if (JSONObject.NULL.equals(diffStateValue)) {
+                        diffStateValue = null;
+                    }
                     equals = equals(fieldValue, referenceFieldValue);
                 }
                 if (!equals) {