Compatibility between git.git and jgit

From: Shawn O. Pearce <spearce@spearce.org>
Date: May 2, 2009, 00:01 UTC
Message-ID: <20090502000123.GF23604@spearce.org>
In-Reply-To: <7v4ow4v0xl.fsf@gitster.siamese.dyndns.org>

Junio C Hamano <gitster@pobox.com> wrote:

Show 6 quoted lines

> The code looks correct, I am reasonably sure updated server-client
> combination would work fine, and use of the capability mechanism means
> other combinations like old pusher and new receiver, and/or new pusher and
> old receiver, should be also Ok.
> 
> I see Shawn did the same to jgit.

On an unrelated note, someone asked me recently, how do we ensure compatibility in implementations between git.git and jgit?

There isn't exactly a great notion of "a Git implementation can do X, Y, Z, and never does Q". So its not like we have a compability test suite to run between the two systems.

JGit is really starting to gain some traction in the open source world.

A lot of folks at Eclipse are really excited about being able to ship a BSD licensed VCS. Some of the Maven folks are really excited about being able to link JGit up to Apache MINA SSHD and have a 100% pure Java server solution for Git, that doesn't require native OS authentication systems. Gerrit Code Review relies entirely on it, and some folks within Google are now using Gerrit Code Review and its embedded MINA SSHD/JGit server as their only Git daemon.

Thus far, our compatibility story with git.git has been, "it should work, uh, we think, because Shawn understands git reasonably well, and wrote some of JGit, so uh, yea....". :-)

But I think in another 12 months we'll be seeing people running only JGit in many contexts, making compatibility between the two implementations somewhat more important than it has been in the past.

-- 
Shawn.