Selecting and deleting the level prefab root entity crashes editor (#1179)

Early remove the level instance from the entity id list in the delete function and duplicate function.

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabPublicHandler.cpp

@@ -901,7 +901,13 @@ namespace AzToolsFramework
                 return AZ::Failure(AZStd::string("No entities to duplicate."));
             }
 
-            if (!EntitiesBelongToSameInstance(entityIds))
+            const EntityIdList entityIdsNoLevelInstance = GenerateEntityIdListWithoutLevelInstance(entityIds);
+            if (entityIdsNoLevelInstance.empty())
+            {
+                return AZ::Failure(AZStd::string("No entities to duplicate because only instance selected is the level instance."));
+            }
+
+            if (!EntitiesBelongToSameInstance(entityIdsNoLevelInstance))
             {
                 return AZ::Failure(AZStd::string("Cannot duplicate multiple entities belonging to different instances with one operation."
                     "Change your selection to contain entities in the same instance."));
@@ -909,7 +915,7 @@ namespace AzToolsFramework
 
             // We've already verified the entities are all owned by the same instance,
             // so we can just retrieve our instance from the first entity in the list.
-            AZ::EntityId firstEntityIdToDuplicate = entityIds[0];
+            AZ::EntityId firstEntityIdToDuplicate = entityIdsNoLevelInstance[0];
             InstanceOptionalReference commonOwningInstance = GetOwnerInstanceByEntityId(firstEntityIdToDuplicate);
             if (!commonOwningInstance.has_value())
             {
@@ -929,7 +935,7 @@ namespace AzToolsFramework
 
             // This will cull out any entities that have ancestors in the list, since we will end up duplicating
             // the full nested hierarchy with what is returned from RetrieveAndSortPrefabEntitiesAndInstances
-            AzToolsFramework::EntityIdSet duplicationSet = AzToolsFramework::GetCulledEntityHierarchy(entityIds);
+            AzToolsFramework::EntityIdSet duplicationSet = AzToolsFramework::GetCulledEntityHierarchy(entityIdsNoLevelInstance);
 
             AZ_PROFILE_FUNCTION(AZ::Debug::ProfileCategory::AzToolsFramework);
 
@@ -1004,17 +1010,19 @@ namespace AzToolsFramework
 
         PrefabOperationResult PrefabPublicHandler::DeleteFromInstance(const EntityIdList& entityIds, bool deleteDescendants)
         {
-            if (entityIds.empty())
+            const EntityIdList entityIdsNoLevelInstance = GenerateEntityIdListWithoutLevelInstance(entityIds);
+
+            if (entityIdsNoLevelInstance.empty())
             {
                 return AZ::Success();
             }
 
-            if (!EntitiesBelongToSameInstance(entityIds))
+            if (!EntitiesBelongToSameInstance(entityIdsNoLevelInstance))
             {
                 return AZ::Failure(AZStd::string("Cannot delete multiple entities belonging to different instances with one operation."));
             }
 
-            AZ::EntityId firstEntityIdToDelete = entityIds[0];
+            AZ::EntityId firstEntityIdToDelete = entityIdsNoLevelInstance[0];
             InstanceOptionalReference commonOwningInstance = GetOwnerInstanceByEntityId(firstEntityIdToDelete);
 
             // If the first entity id is a container entity id, then we need to mark its parent as the common owning instance because you
@@ -1025,7 +1033,7 @@ namespace AzToolsFramework
             }
 
             // Retrieve entityList from entityIds
-            EntityList inputEntityList = EntityIdListToEntityList(entityIds);
+            EntityList inputEntityList = EntityIdListToEntityList(entityIdsNoLevelInstance);
 
             AZ_PROFILE_FUNCTION(AZ::Debug::ProfileCategory::AzToolsFramework);
 
@@ -1081,7 +1089,7 @@ namespace AzToolsFramework
                 }
                 else
                 {
-                    for (AZ::EntityId entityId : entityIds)
+                    for (AZ::EntityId entityId : entityIdsNoLevelInstance)
                     {
                         InstanceOptionalReference owningInstance = m_instanceEntityMapperInterface->FindOwningInstance(entityId);
                         // If this is the container entity, it actually represents the instance so get its owner
@@ -1437,6 +1445,22 @@ namespace AzToolsFramework
             return (outEntities.size() + outInstances.size()) > 0;
         }
 
+        EntityIdList PrefabPublicHandler::GenerateEntityIdListWithoutLevelInstance(
+            const EntityIdList& entityIds) const
+        {
+            EntityIdList outEntityIds;
+            outEntityIds.reserve(entityIds.size()); // Actual size could be smaller.
+
+            for (const AZ::EntityId& entityId : entityIds)
+            {
+                if (!IsLevelInstanceContainerEntity(entityId))
+                {
+                    outEntityIds.emplace_back(entityId);
+                }
+            }
+            return outEntityIds;
+        }
+
         bool PrefabPublicHandler::EntitiesBelongToSameInstance(const EntityIdList& entityIds) const
         {
             if (entityIds.size() <= 1)

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/PrefabPublicHandler.h

@@ -70,6 +70,7 @@ namespace AzToolsFramework
             PrefabOperationResult DeleteFromInstance(const EntityIdList& entityIds, bool deleteDescendants);
             bool RetrieveAndSortPrefabEntitiesAndInstances(const EntityList& inputEntities, Instance& commonRootEntityOwningInstance,
                 EntityList& outEntities, AZStd::vector<Instance*>& outInstances) const;
+            EntityIdList GenerateEntityIdListWithoutLevelInstance(const EntityIdList& entityIds) const;
 
             InstanceOptionalReference GetOwnerInstanceByEntityId(AZ::EntityId entityId) const;
             bool EntitiesBelongToSameInstance(const EntityIdList& entityIds) const;