HV-1480 Only set the property value if required

Only property and container node exposes it to users.

Author: gsmet

engine/src/main/java/org/hibernate/validator/internal/engine/ValueContext.java

@@ -192,7 +192,7 @@ public final void setCurrentGroup(Class<?> currentGroup) {
 	}
 
 	public final void setCurrentValidatedValue(V currentValue) {
-		propertyPath.setLeafNodeValue( currentValue );
+		propertyPath.setLeafNodeValueIfRequired( currentValue );
 		this.currentValue = currentValue;
 	}
 

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

@@ -222,13 +222,16 @@ public NodeImpl makeLeafNodeIterableAndSetMapKey(Object key) {
 		return currentLeafNode;
 	}
 
-	public NodeImpl setLeafNodeValue(Object value) {
-		requiresWriteableNodeList();
+	public NodeImpl setLeafNodeValueIfRequired(Object value) {
+		// The value is only exposed for property and container element nodes
+		if ( currentLeafNode.getKind() == ElementKind.PROPERTY || currentLeafNode.getKind() == ElementKind.CONTAINER_ELEMENT ) {
+			requiresWriteableNodeList();
 
-		currentLeafNode = NodeImpl.setPropertyValue( currentLeafNode, value );
+			currentLeafNode = NodeImpl.setPropertyValue( currentLeafNode, value );
 
-		nodeList.set( nodeList.size() - 1, currentLeafNode );
-		hashCode = -1;
+			nodeList.set( nodeList.size() - 1, currentLeafNode );
+			hashCode = -1;
+		}
 		return currentLeafNode;
 	}