+int UI_dup_user_data(UI *ui, void *user_data)
+{
+ void *duplicate = NULL;
+
+ if (ui->meth->ui_duplicate_data == NULL
+ || ui->meth->ui_destroy_data == NULL) {
+ UIerr(UI_F_UI_DUP_USER_DATA, UI_R_USER_DATA_DUPLICATION_UNSUPPORTED);
+ return -1;
+ }
+
+ duplicate = ui->meth->ui_duplicate_data(ui, user_data);
+ if (duplicate == NULL) {
+ UIerr(UI_F_UI_DUP_USER_DATA, ERR_R_MALLOC_FAILURE);
+ return -1;
+ }
+
+ (void)UI_add_user_data(ui, duplicate);
+ ui->flags |= UI_FLAG_DUPL_DATA;
+
+ return 0;
+}
+