I am in the process of making an INDI focuser driver for RPi with the A4988 stepper driver, but have run into a problem with the INDI API.
If I delete a IUFillSwitchVector property with more than 4 attributes from the Options tab, it is not being properly removed. See focus_simulator.png for before and after screen captures of driver control panel.
The attached patch file reproduces problem using the INDI focus_simulator.cpp driver code.