Re: git-svn and svn:externals, was Re: Hackontest ideas?

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Aug 3, 2008, 23:24 UTC
Message-ID: <alpine.DEB.1.00.0808040113150.9611@pacific.mpi-cbg.de.mpi-cbg.de>
In-Reply-To: <20080803224852.GC3006@untitled>

Hi,

On Sun, 3 Aug 2008, Eric Wong wrote:

Show 11 quoted lines

> Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
>
> > The main concern I have is to get the semantics right: AFAICT 
> > svn:externals has _no notion_ of "what is current".  It just _always_ 
> > fetches the HEAD.  Even if you check out an ancient revision in the 
> > "superproject".
> 
> Based on my limited understanding, peg revisions are only needed in SVN 
> because of the cost of traversing history to DTRT.  git-svn should be 
> able to just use the -r<rev> syntax that has always been supported 
> without needing peg revisions.

I was talking about the svn -> git direction.

And Git does not peg revisions because of the cost of traversing history to DTRT.

Git pegs revisions of submodules, because it is the right thing to do. Subversion just got it wrong to begin with. After all, we are going through a lot to make defined revisions, and we do not want to throw that out by allowing an unversioned submodule.

So, importing a svn:external with git-svn has to undo that error somehow (which might be helped by the linearity of subversion, but might be tricky because of possible clock skews between the two subversion repositories).

Ciao, Dscho