solana program write-buffer does not respect --buffer-authority

[ruuda]

See #17890, which was automatically closed despite not being resolved.

[CriesofCarrots]

Looks like the issue is that solana program write-buffer expects --buffer-authority to be a signer, not a pubkey:

$ solana program write-buffer -h
...
--buffer-authority <BUFFER_AUTHORITY_SIGNER>    Buffer authority [default: the default configured keypair]

The command doesn't error on a pubkey string input for the parameter because that can potentially be a signer, if accompanied by an offline signing pair.

But I'm not sure that --buffer-authority needs to be a signer in the first place. As you noted in the original issue, solana program set-buffer-authority just accepts a pubkey for the --new-buffer-authority. I'll take a look.

(edit) Oh, I see. --buffer-authority always needs to be a signer to perform the Write transactions. So I think the best way to fix is to return an error if a Pubkey is supplied, since the command doesn't support offline signing.