Re: [RFC PATCH] config: teach `repo_config()` to allow `repo` to be NULL

> The `repo` value can be NULL if a builtin command is run outside
> any repository. The current implementation of `repo_config()` will
> fail if `repo` is NULL.
>
> If the `repo` is NULL the `repo_config()` can ignore the repository
> configuration but it should read the other configuration sources like
> the system-side configuration instead of failing.

> Teach the `repo_config()` to allow `repo` to be NULL by calling the
> `read_very_early_config()` which read config but only enumerate system
> and global settings.
>
> Suggested-by: Junio C Hamano <gitster@pobox.com>
> Mentored-by: Christian Couder <chriscool@tuxfamily.org>
> Signed-off-by: Usman Akinyemi <usmanakinyemi202@gmail.com>