From: Jeff King <peff@peff.net>
Date: Thu, 23 Feb 2017 05:58:31 GMT
Subject: Re: [PATCH v2] config: reject invalid VAR in 'git -c VAR=VAL command'
Message-ID: <20170223055831.u3yofkby3c56t7l4@sigill.intra.peff.net>
In-Reply-To: <xmqqd1ebfd9l.fsf_-_@gitster.mtv.corp.google.com>

On Tue, Feb 21, 2017 at 01:24:38PM -0800, Junio C Hamano wrote:

> The parsing of one-shot assignments of configuration variables that
> come from the command line historically was quite loose and allowed
> anything to pass.
> 
> The configuration variable names that come from files are validated
> in git_config_parse_source(), which uses get_base_var() that grabs
> the <section> (and subsection) while making sure that <section>
> consists of iskeychar() letters, the function itself that makes sure
> that the first letter in <variable> is isalpha(), and get_value()
> that grabs the remainder of the <variable> name while making sure
> that it consists of iskeychar() letters.
> 
> Perform an equivalent check in canonicalize_config_variable_name()
> to catch invalid configuration variable names that come from the
> command line.

FWIW, the code looks OK here. It is a shame to duplicate the policy
found in git_config_parse_key(), though.

I wonder if we could make a master version of that which canonicalizes
in-place, and then just wrap it for the git_config_parse_key()
interface. Actually, I guess the function you just wrote _is_ that inner
function, as long as it learned about the "quiet" flag.

-Peff