API: Setting value to NULL

I’m working on a script to manage some settings through the API.

Everything works, with one small exception. Some settings are reported as being null, I can’t figure out how to set that value. E.g. on the page documenting the Application settings API (https://docs.gitlab.com/ee/api/settings.html), after_sign_out_path is shown in the example response to be null.

If I use after_sign_out_path=null in an API call to modify it, it gets set to the string “null”, and if I use after_sign_out_path= it gets set to the empty string.

(In the case of after_sign_out_path null is not really a useable value, and I guess that might generally be true, but is it not possible to restore the default anyway (there’s no default listed for after_sign_out_path - see https://gitlab.com/gitlab-org/gitlab-ce/issues/55235 - but null is specified to be the default value for other settings)?