dos_getdir behaviour with "Make New Folder" flag

[cadconcepts]

I noticed that dos_getdir will show the "Make New Folder" when the associated flag is actively set to nil e.g.
(dos_getdir "Browse for folder" (getvar 'DWGPREFIX) "Select a folder to use" nil)

i.e. if the option flag is present, then the "Make New Folder" will display.

This means you can't pass the folder option as a variable e.g

(dos_getdir "Browse for folder" (getvar 'DWGPREFIX) "Select a folder to use" (getkword "Press Enter to return nil"))

Perhaps the function should test to see whether the flag past is nil?

If you don't want to show the button, you must omit inclusion of the flag altogether.
(dos_getdir "Browse for folder" (getvar 'DWGPREFIX) "Select a folder to use")