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

On 02/27, Jonathan Nieder wrote:

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.
After all, future Git versions might add even more protocol versions,
and using two different Git versions with the same Git repo, machine,
or home directory should not cripple the older Git version just
because of a parameter that is only understood by a more recent Git
version.

So ignore the unrecognized value.  It may be useful for spell checking
(for instance, if I put "version = v1" intending "version = 1") to
warn about such settings, but this patch does not, since at least in
these early days for protocol v2 it is expected for configurations
that want to opportunistically use protocol v2 if available not to be
unusual.

Signed-off-by: Jonathan Nieder <redacted>
---
Google has been running with a patch like this internally for a while,
since we have been changing the protocol.version number to a new value
like 20180226 each time a minor tweak to the protocolv2 RFC occured.

The bit I have doubts about is whether to warn.  What do you think?

Patch looks good to me.  And I don't have a strong preference either way
for whether to warn or not.


-- 
Brandon Williams