Modified Node.clone() to update the parent field of each child to poi…

…nt to it's cloned parent (instead of the original nodes as it was). Added a test to validate this.

node_mutations.go

@@ -184,7 +184,9 @@ func (n *Node) clone() *Node {
 		dirty:    n.dirty,
 	}
 	for key, value := range n.children {
-		node.children[key] = value.clone()
+		clone := value.clone()
+		clone.parent = node
+		node.children[key] = clone
 	}
 	return node
 }

node_mutations_test.go

@@ -1380,6 +1380,7 @@ func TestNode_Clone(t *testing.T) {
 	null := NullNode("")
 	array := ArrayNode("", []*Node{node, null})
 	object := ObjectNode("", map[string]*Node{"array": array})
+	objectWithObject := ObjectNode("", map[string]*Node{"object": object})
 
 	tests := []struct {
 		name string
@@ -1406,6 +1407,11 @@ func TestNode_Clone(t *testing.T) {
 			node: object,
 			json: `{"array":[1.1,null]}`,
 		},
+		{
+			name: "objectWithObject",
+			node: objectWithObject,
+			json: `{"object":{"array":[1.1,null]}}`,
+		},
 	}
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
@@ -1427,10 +1433,23 @@ func TestNode_Clone(t *testing.T) {
 			} else if string(base) != test.json {
 				t.Errorf("Marshal() base not match: \nExpected: %s\nActual: %s", test.json, base)
 			}
+
+			validateParent(t, clone)
 		})
 	}
 }
 
+// validateParent checks if all children have the correct parent, recursively.
+func validateParent(t *testing.T, node *Node) {
+	for _, child := range node.Inheritors() {
+		if child.Parent() != node {
+			t.Errorf("Inheritor.Parent() != node")
+		}
+
+		validateParent(t, child)
+	}
+}
+
 func ExampleNode_Clone() {
 	root := Must(Unmarshal(jsonPathTestData))
 	nodes, _ := root.JSONPath("$..price")