rgw_sal_motr : [CORTX-32387] Fix null version-id issues in GET/HEAD o…

…bject API (#377)

Problem: GET and HEAD object with null version-id does not contain "VersionId" field in the response

Solution: In GET/HEAD object with --version-id null parameter for simple and multipart object, set the ent.key.instance value as null to show the VersionId field in the response.

Signed-off-by: Priyanka Salunke <priyanka.s.salunke@seagate.com>

src/rgw/rgw_sal_motr.cc

@@ -3181,6 +3181,11 @@ int MotrObject::get_bucket_dir_ent(const DoutPrefixProvider *dpp, rgw_bucket_dir
   key.set(ent.key);
   obj_key = key.name + '\a' + key.instance;
 
+  // Set the instance value as "null" to show
+  // the VersionId field in the GET/HEAD object response
+  if (this->get_key().have_null_instance())
+    ent.key.instance = "null";
+
   // Put into the cache
   this->store->get_obj_meta_cache()->put(dpp, obj_key, bl);