fix oss list in some certain condition

Author: Coldwings

ecosystem/oss.cpp

@@ -509,12 +509,14 @@ int OssClient::walk_list_results(const SimpleDOM::Node& list_bucket_result,
     auto type = NodeStrValue(child["Type"]);
 
     if (!key.has_value() || !size.has_value() || !mtime.has_value() ||
-        !etag.has_value() || !type.has_value())
+        !etag.has_value())
       LOG_ERROR_RETURN(EINVAL, -1,
                        "unexpected response: missing required fields");
 
+    estring_view type_sv = type.has_value() ? static_cast<estring_view>(type) : estring_view();
+
     auto mtim = get_list_lastmodified(mtime);
-    auto r = cb({key, etag, type, static_cast<size_t>(size), mtim,
+    auto r = cb({key, etag, type_sv, static_cast<size_t>(size), mtim,
                  false /*not comm prefix*/});
     if (r < 0) return r;
   }