Fix Tree copy by doing a shallow copy of the value (#5081)

* Fix Tree copy by doing a shallow copy of the value

* Update cloneValue implementation to be recursive

components/lib/tree/Tree.js

@@ -58,9 +58,32 @@ export const Tree = React.memo(
             dragState.current = null;
         };
 
+        /**
+         * Deep copy a value. If the value has a data property, it will be shallow copied.
+         * Values that are not plain objects or arrays are returned as-is.
+         */
+        const cloneValue = (value) => {
+            if (Array.isArray(value)) {
+                return value.map(cloneValue);
+            } else if (!!value && Object.getPrototypeOf(value) === Object.prototype) {
+                const result = {};
+
+                // Leave data property alone and clone children
+                for (let key in value) {
+                    if (key !== 'data') {
+                        result[key] = cloneValue(value[key]);
+                    } else {
+                        result[key] = value[key];
+                    }
+                }
+
+                return result;
+            } else return value;
+        };
+
         const onDrop = (event) => {
             if (validateDropNode(dragState.current.path, event.path)) {
-                let value = JSON.parse(JSON.stringify(props.value));
+                const value = cloneValue(props.value);
                 let dragPaths = dragState.current.path.split('-');
 
                 dragPaths.pop();
@@ -89,7 +112,7 @@ export const Tree = React.memo(
 
         const onDropPoint = (event) => {
             if (validateDropPoint(event)) {
-                let value = JSON.parse(JSON.stringify(props.value));
+                const value = cloneValue(props.value);
                 let dragPaths = dragState.current.path.split('-');
 
                 dragPaths.pop();