fix sibling pollution in json schema property recursion

core/src/main/java/it/extared/dpp/validator/json/JsonSchemaMetadataExtractor.java

@@ -168,17 +168,16 @@ private Set<String> extractRequiredPaths(
         }
 
         // Traverse non-required properties too to find nested required paths.
-        // Needed for schemas like AAS where the root has no required fields
-        // but nested definitions do.
         if (propertiesNode != null) {
             for (Map.Entry<String, JsonNode> entry : propertiesNode.properties()) {
                 String propName = entry.getKey();
                 if (requiredFields.contains(propName)) continue;
                 String fullPath = currentPath.isEmpty() ? propName : currentPath + "." + propName;
-                paths.addAll(recurseIntoProperty(entry.getValue(), root, fullPath, visited));
+                Set<JsonNode> siblingVisited = Collections.newSetFromMap(new IdentityHashMap<>());
+                siblingVisited.addAll(visited);
+                paths.addAll(recurseIntoProperty(entry.getValue(), root, fullPath, siblingVisited));
             }
         }
-
         return paths;
     }
 

core/src/test/java/it/extrared/dpp/validator/json/JsonPropertyExtractorTest.java

@@ -38,4 +38,10 @@ public void testJsonPropertyExtraction() throws JsonProcessingException {
         props = extractor.extractAllPaths(CommonUtils.readJsonNode("invalid-battery.json"));
         assertEquals(42, props.size());
     }
+
+    @Test
+    public void testJsonPropertyExtraction2() throws JsonProcessingException {
+        Set<String> props = extractor.extractAllPaths(CommonUtils.readJsonNode("aas-bike.json"));
+        assertEquals(64, props.size());
+    }
 }

core/src/test/java/it/extrared/dpp/validator/json/JsonSchemaMetadataExtractorTest.java

@@ -63,7 +63,7 @@ public void testExtraction3() {
     public void testExtraction4() {
         SchemaMetadata schema =
                 extractor.extractMetadata(CommonUtils.readJsonSchemaNode("test-aas-schema.json"));
-        assertEquals(16, schema.getRequiredPaths().size());
+        assertEquals(111, schema.getRequiredPaths().size());
         assertFalse(schema.isHasVariants());
         assertEquals(0, schema.getPatternProperties().size());
     }