App: Remove old DAG implementation.

src/App/Transactions.cpp

@@ -464,7 +464,6 @@ void TransactionDocumentObject::applyDel(Document& Doc, TransactionalObject* pcO
     if (status == Del) {
         DocumentObject* obj = static_cast<DocumentObject*>(pcObj);
 
-#ifndef USE_OLD_DAG
         // Make sure the backlinks of all linked objects are updated. As the links of the removed
         // object are never set to [] they also do not remove the backlink. But as they are
         // not in the document anymore we need to remove them anyway to ensure a correct graph
@@ -472,7 +471,6 @@ void TransactionDocumentObject::applyDel(Document& Doc, TransactionalObject* pcO
         for (auto link : list) {
             link->_removeBackLink(obj);
         }
-#endif
 
         // simply filling in the saved object
         Doc._removeObject(obj);
@@ -485,13 +483,11 @@ void TransactionDocumentObject::applyNew(Document& Doc, TransactionalObject* pcO
         DocumentObject* obj = static_cast<DocumentObject*>(pcObj);
         Doc._addObject(obj, _NameInDocument.c_str());
 
-#ifndef USE_OLD_DAG
         // make sure the backlinks of all linked objects are updated
         auto list = obj->getOutList();
         for (auto link : list) {
             link->_addBackLink(obj);
         }
-#endif
     }
 }