Fix setting File as value in store (T1327666)

packages/devextreme/js/__internal/core/utils/m_object.ts

@@ -10,6 +10,10 @@ const clone = (function () {
   };
 })();
 
+const isBlobLike = function (value: unknown): boolean {
+  return typeof Blob !== 'undefined' && value instanceof Blob;
+};
+
 const orderEach = function (map, func) {
   const keys: string[] = [];
   let key;
@@ -93,6 +97,10 @@ const deepExtendArraySafe = function (target, changes, extendComplexObject?, ass
   let newValue;
   const assignFunc = useNewAssign ? newAssign : legacyAssign;
 
+  if (isBlobLike(changes)) {
+    return changes;
+  }
+
   for (const name in changes) {
     prevValue = target[name];
     newValue = changes[name];

packages/devextreme/testing/tests/DevExpress.core/utils.object.tests.js

@@ -221,3 +221,18 @@ QUnit.test('deepExtendArraySafe preserves custom object instances in arrays', fu
     assert.ok(result.items[0] instanceof CustomClass, 'First item preserves custom type');
     assert.ok(result.items[1] instanceof CustomClass, 'Second item preserves custom type');
 });
+
+QUnit.test('deepExtendArraySafe assigns Blob/File by reference without throwing (nested newAssign)', function(assert) {
+    const file = new File(['x'], 'test.txt', { type: 'text/plain' });
+    const blob = new Blob(['y']);
+
+    const target = { id: 1, file: null, data: null };
+
+    objectUtils.deepExtendArraySafe(target, { file: file, data: blob }, true, false, true, objectUtils.newAssign);
+
+    assert.strictEqual(target.file, file);
+    assert.strictEqual(target.data, blob);
+
+    const merged = objectUtils.deepExtendArraySafe({}, file, true, false, true, objectUtils.newAssign);
+    assert.strictEqual(merged, file);
+});