fix: Prevent extractQuadsRecursive infinite loop

Author: joachimvh

packages/ucp/src/util/Util.ts

@@ -6,25 +6,23 @@ import { Store } from "n3";
  * @param store
  * @param subjectIRI
  * @param existing IRIs that already have done the recursive search (IRIs in there must not be searched for again)
- * @returns
  */
-
 export function extractQuadsRecursive(store: Store, subjectIRI: string, existing?: string[]): Store {
     const tempStore = new Store();
     const subjectIRIQuads = store.getQuads(subjectIRI, null, null, null);
 
     tempStore.addQuads(subjectIRIQuads);
-    const existingSubjects = existing ?? [subjectIRI];
+    const existingSubjects = [ ...existing ?? [] ];
+    existingSubjects.push(subjectIRI);
 
     for (const subjectIRIQuad of subjectIRIQuads) {
         if (!existingSubjects.includes(subjectIRIQuad.object.id)) {
-            tempStore.addQuads(extractQuadsRecursive(store, subjectIRIQuad.object.id, existingSubjects).getQuads(null, null, null, null));
+            tempStore.addQuads(extractQuadsRecursive(store, subjectIRIQuad.object.id, existingSubjects)
+                .getQuads(null, null, null, null));
         }
         else {
             tempStore.addQuad(subjectIRIQuad);
         }
-        existingSubjects.push(subjectIRIQuad.object.id);
     }
     return tempStore;
-}// instantiated policy consisting of one agreement and one rule
-
+}