Re: git-svn and branches

[Eric Wong <normalperson@yhbt.net>]

Steven Walter <stevenrwalter@gmail.com> wrote:
> I'm using git-svn to track a rather large subversion repository with a
> non-standard layout.  In the past, I've only cared about trunk, but now
> I need to occasionally use branches, too.  By adding a second git-svn
> remote with the branch URL, I can fetch the branch, and git-svn is even
> intelligent enough to notice that the branch was copied off of trunk.
> 
> However, git-svn also does a complete checkout for the first revision of
> the branch.  By this, I mean it goes through shows "A    file" for every
> file in the repository.  This takes quite a while, and seems rather
> unnecessary given that git-svn already noticed that the branch shares a
> history with trunk, which is already fetched.
> 
> Knowing just enough of what git-svn is doing to be dangerous, I whipped
> up a short little patch.  This patch seems to work for the common case,
> and avoids fetching every file from subversion.  It does break
> sometimes, however, and I don't understand why.
> 
> Maybe someone with a better grasps of the code can see what I did wrong,
> or suggest a better means to my end?

I believe your case handles where a branch is created directly from a
trunk copy with no file modifications in the branch, but not when a
branch is created and files are modified in the trunk (or branch) within
the same revision.  Is this what's happening?

Additionally, I think this breaks when an entire trunk or branch is
moved around because the original directory has moved or gone away:

  /trunk => /project-a/trunk

Anyways, as Sam said, newer SVN (1.4.4+) has a working do_switch()
function and that code path will never be hit at all.

> diff --git a/git-svn.perl b/git-svn.perl
> index 484b057..1bc92b6 100755
> --- a/git-svn.perl
> +++ b/git-svn.perl
> @@ -1848,9 +1848,10 @@ sub find_parent_branch {
>                                               $self->full_url, $ed)
>                           or die "SVN connection failed somewhere...\n";
>                 } else {
> +                       $self->assert_index_clean($parent);
>                         print STDERR "Following parent with do_update\n";
>                         $ed = SVN::Git::Fetcher->new($self);
> -                       $self->ra->gs_do_update($rev, $rev, $self, $ed)
> +                       $self->ra->gs_do_update($rev, $r0, $self, $ed)
>                           or die "SVN connection failed somewhere...\n";
>                 }
>                 print STDERR "Successfully followed parent\n";

-- 
Eric Wong