Re: git-svn and repository hierarchy?

From: Peter Harris <git@peter.is-a-geek.org>
Date: Mar 4, 2009, 00:18 UTC
Message-ID: <eaa105840903031618s5e0b6f24j64aade8d752fb11@mail.gmail.com>
In-Reply-To: <20090303223600.GB11278@raven.wolf.lan>

On Tue, Mar 3, 2009 at 5:36 PM, Josef Wolf wrote:

>
> I'd rather not let every clone talk to subversion for several reasons.
> One of them is that it is very inconvenient (e.g. the password has to
> be entered several times for every commit).

Sounds like subversion isn't properly caching your credentials, or your admin is paranoid and turned off the svn credential cache. I can't remember the last time I had to enter a password.

Of course, git-svn-repo can't cache credentials, since it has to impersonate different users. You are impersonating different users so that the svn author field is correct, aren't you? But that shouldn't be a problem for userN working on cloneN.

>  After all, the whole point
> for having git-svn-repos is for the clone to avoid working directly
> against the subversion repos.  If every clone works against subversion
> anyway, I can get rid of git-svn-repos as well.

From my perspective, the main advantage of git-svn-repos is the inital clone. Subversion is way too slow to clone an entire project's history (days, vs minutes for git). Subsequent 'git pull --rebase's are faster than 'git svn rebase's, too, although not by the same ratio (except for large subtree moves, which really are that much faster).

Show 16 quoted lines

> On Tue, Mar 03, 2009 at 02:35:28PM -0500, Peter Harris wrote:
>> Also, this line says "rebase my changes onto those of ../clone$clone",
>> which isn't what you want. It will end up rebasing svn commits that
>> the client didn't have on top of the client's commits, and will break
>> git-svn's index. Don't use --rebase here.
>
> Hmm, I must have misunderstood Michael, then.  Wasn't he suggesting
> to rebase here?  Here's the citation:
>
> |>   (cd git-svn-repos; git pull ../clone1)  # if this line is executed,
> |
> |That's the problem. This creates a merge after which you 1-2-3-4 and
> |1-2'-3'-4' plus the merge of 4 and 4'.
> |
> |Instead, use git pull --rebase here. You don't want merges in the branch
> |from which you dcommit.

I think he meant to say "git pull ../cloneN && git rebase trunk".

Show 8 quoted lines

>> >  # Although we have resolved the conflict, spurious conflicts are
>> >  # propagated to the clones
>>
>> ...and this is because you had clones all merge from each other (via
>> git-svn-repos) *before* the changes were in svn.
>
> Does that mean that the conflicts would disappear if I do
> git-svn-rebase + git-svn-dcommit after every pull from a clone?

Well, 'disappear' is a strong word. "cloneX" has to be willing to reset to your branch if you have resolved any conflicts on behalf of cloneX. But the other cloneNs should not see those conflicts, at least.

Not to mention that it's not outside the realm of possibility that various cloneNs may be working with each other without involving you.

Plus, there is a small window where clones may be pulling from each other, and will have to resolve the same conflicts you resolve during your "git svn dcommit". I'm sure you've heard the saying "Every computer science problem can be solved by adding a level of indirection." You could add a git-svn-stage that pulls from cloneN and does the dcommit (and then pushes to git-svn-repos, or lets git-svn-repos do its own "git svn fetch"), leaving git-svn-repos clean for cloneN to pull from...

Peter Harris