ATLAS-2141: edit/disassociate tag results in NPE

repository/src/main/java/org/apache/atlas/repository/graph/GraphHelper.java

@@ -1079,8 +1079,12 @@ public final class GraphHelper {
 
     }
 
+    public static boolean isInternalType(AtlasVertex vertex) {
+        return vertex != null && isInternalType(getTypeName(vertex));
+    }
+
     public static boolean isInternalType(String typeName) {
-        return typeName.startsWith(Constants.INTERNAL_PROPERTY_KEY_PREFIX);
+        return typeName != null && typeName.startsWith(Constants.INTERNAL_PROPERTY_KEY_PREFIX);
     }
 
     public static void setArrayElementsProperty(IDataType elementType, AtlasVertex instanceVertex, String propertyName, List<Object> values) {

repository/src/main/java/org/apache/atlas/repository/store/graph/v1/AtlasEntityChangeNotifier.java

@@ -227,14 +227,10 @@ public class AtlasEntityChangeNotifier {
         }
 
         for (AtlasEntityHeader atlasEntityHeader : atlasEntityHeaders) {
-            if(GraphHelper.isInternalType(atlasEntityHeader.getTypeName())) {
-                continue;
-            }
-
             String      guid        = atlasEntityHeader.getGuid();
             AtlasVertex atlasVertex = AtlasGraphUtilsV1.findByGuid(guid);
 
-            if(atlasVertex == null) {
+            if(atlasVertex == null || GraphHelper.isInternalType(atlasVertex)) {
                 continue;
             }
 
@@ -262,12 +258,7 @@ public class AtlasEntityChangeNotifier {
         }
 
         AtlasVertex atlasVertex = AtlasGraphUtilsV1.findByGuid(entityId);
-        if(atlasVertex == null) {
-            return;
-        }
-
-        if (atlasVertex == null) {
-            LOG.warn("updateFullTextMapping(): no entity exists with guid {}", entityId);
+        if(atlasVertex == null || GraphHelper.isInternalType(atlasVertex)) {
             return;
         }
 

webapp/src/main/java/org/apache/atlas/notification/NotificationEntityChangeListener.java

@@ -187,7 +187,9 @@ public class NotificationEntityChangeListener implements EntityChangeListener {
             messages.add(notification);
         }
 
-        notificationInterface.send(NotificationInterface.NotificationType.ENTITIES, messages);
+        if (!messages.isEmpty()) {
+            notificationInterface.send(NotificationInterface.NotificationType.ENTITIES, messages);
+        }
     }
 
     private List<String> getNotificationAttributes(String entityType) {