ral calls to this function doesn&#39;t add data, it replaces the previous blob with the one given as argument.</p>

<p>UI_dup_user_data() duplicates the user data and works as an alternative to UI_add_user_data() when the user data needs to be preserved for a longer duration, perhaps even the lifetime of the application. The UI object takes ownership of this duplicate and will free it whenever it gets replaced or the UI is destroyed. UI_dup_user_data() returns 0 on success, or -1 on memory allocation failur