Returns the list of actions (possibly empty) that accel maps to. Each item in the list is a detailed action name in the usual form.
This might be useful to discover if an accel already exists in order to prevent installation of a conflicting accelerator (from an accelerator editor or a plugin system, for example). Note that having more than one action per accelerator may not be a bad thing and might make sense in cases where the actions never appear in the same context.
In case there are no actions for a given accelerator, an empty array is returned. NULL is never returned.
It is a programmer error to pass an invalid accelerator string. If you are unsure, check it with gtk_accelerator_parse() first.