Modify tender only if patch data available

src/openprocurement/api/tests/tender.py

@@ -201,6 +201,15 @@ def test_patch_tender(self):
         self.assertEqual(tender, new_tender)
         self.assertNotEqual(modified, new_modified)
 
+        response = self.app.patch_json('/tenders/{}'.format(
+            tender['id']), {'data': {'modified': new_modified}})
+        self.assertEqual(response.status, '200 OK')
+        self.assertEqual(response.content_type, 'application/json')
+        new_tender2 = response.json['data']
+        new_modified2 = new_tender2.pop('modified')
+        self.assertEqual(new_tender, new_tender2)
+        self.assertEqual(new_modified, new_modified2)
+
     def test_modified_tender(self):
         response = self.app.get('/tenders')
         self.assertEqual(response.status, '200 OK')

src/openprocurement/api/views.py

@@ -490,13 +490,14 @@ def patch(self):
             self.request.errors.status = 404
             return
         tender_data = filter_data(self.request.json_body['data'])
-        if 'tenderID' not in tender_data:
-            tender_data['tenderID'] = tender.tenderID
-        try:
-            tender.import_data(tender_data)
-            tender.store(self.db)
-        except Exception, e:
-            return self.request.errors.add('body', 'data', str(e))
+        if tender_data:
+            if 'tenderID' not in tender_data:
+                tender_data['tenderID'] = tender.tenderID
+            try:
+                tender.import_data(tender_data)
+                tender.store(self.db)
+            except Exception, e:
+                return self.request.errors.add('body', 'data', str(e))
         return {'data': tender.serialize("view")}