Re: [PATCH] protocol: treat unrecognized protocol.version setting as 0

[Junio C Hamano <gitster@pobox.com>]

Jonathan Nieder <jrnieder@gmail.com> writes:

> If I share my .gitconfig or .git/config file between multiple machines
> (or between multiple Git versions on a single machine) and set
>
> 	[protocol]
> 		version = 2
>
> then running "git fetch" with a Git version that does not support
> protocol v2 errors out with
>
> 	fatal: unknown value for config 'protocol.version': 2
>
> In the spirit of v1.7.6-rc0~77^2~1 (Improve error handling when
> parsing dirstat parameters, 2011-04-29), it is better to (perhaps
> after warning the user) ignore the unrecognized protocol version.

I do not agree with the analogy at all.  

Showing dirstat with different tweaks than the user expected to see
is a local and read-only thing.  Talking to the other side over a
protocol the user explicitly wanted to avoid (e.g. imagine the case
where your upstream's protocol version 1 implementation is
critically buggy and you want to use version 2 if you talk with
them) by accident is a more grave error, possibly affecting the
other side that you may not have enough power to recover from
(e.g. damaging the remote repository to which you only have push
access and not interactive shell).