Copy nodes when changing the nature of the leaf

engine/src/main/java/org/hibernate/validator/internal/engine/path/PathImpl.java

@@ -195,7 +195,7 @@ private NodeImpl addMethodNode(String name, Class<?>[] parameterTypes) {
 	}
 
 	public NodeImpl makeLeafNodeIterable() {
-		requiresWriteableNodeList();
+		copyNodeList();
 
 		currentLeafNode = NodeImpl.makeIterable( currentLeafNode );
 
@@ -205,7 +205,7 @@ public NodeImpl makeLeafNodeIterable() {
 	}
 
 	public NodeImpl makeLeafNodeIterableAndSetIndex(Integer index) {
-		requiresWriteableNodeList();
+		copyNodeList();
 
 		currentLeafNode = NodeImpl.makeIterableAndSetIndex( currentLeafNode, index );
 
@@ -215,7 +215,7 @@ public NodeImpl makeLeafNodeIterableAndSetIndex(Integer index) {
 	}
 
 	public NodeImpl makeLeafNodeIterableAndSetMapKey(Object key) {
-		requiresWriteableNodeList();
+		copyNodeList();
 
 		currentLeafNode = NodeImpl.makeIterableAndSetMapKey( currentLeafNode, key );
 
@@ -300,6 +300,10 @@ private void requiresWriteableNodeList() {
 			return;
 		}
 
+		copyNodeList();
+	}
+
+	private void copyNodeList() {
 		// Usually, the write operation is about adding one more node, so let's make the list one element larger.
 		List<Node> newNodeList = new ArrayList<>( nodeList.size() + 1 );
 		newNodeList.addAll( nodeList );