make sure all schemas are unreferenced

Author: max-at-silverflow

src/middlewares/parsers/schema.preprocessor.ts

@@ -217,7 +217,7 @@ export class SchemaPreprocessor<
       state: VisitorState,
     ) => {
       try {
-        if (node.object === undefined || seenObjects.has(node.object)) {
+        if (node.object === undefined) {
           return;
         }
 
@@ -244,6 +244,8 @@ export class SchemaPreprocessor<
           return traverse(parent, node as VisitorNode<NodeType>, state);
         }
 
+        if (seenObjects.has(node.object)) return;
+
         seenObjects.add(node.object);
 
         this.visitNode(parent, node, state);