What git config --replace-all ONE_ARG should do?

The command 'git config --replace-all ONE_ARG' currently tries to do the same as the command 'git config NAME VALUE', using --replace-all as the NAME and ONE_ARG as VALUE, printing "key does not contain a section: --replace-all".

What this command should do? I'm almost finnishing buitin-config.c to use parse-options and I need to know if that command should do something or just showing the help and exit in such case.

I think that --replace-all should always receive at least two arguments. The documentation currently says: git-config ... --replace-all name [value [value_regex]] and current tests are only cheking two arguments.

Since I cannot imagine a consistent action to do when only the name is given and nobody complains I will do this to print the help message and exit.

Cheers

-- Carlos