Creates a #GSimpleAsyncResult from an error condition.
a #GObject, or %NULL.
a #GAsyncReadyCallback.
user data passed to @callback.
a #GError
Return: a #GSimpleAsyncResult.
Deprecated: Use g_task_new() and g_task_return_error() instead.
ConstructionException GTK+ fails to create the object.
See Implementation
Creates a #GSimpleAsyncResult from an error condition.