threads / discuss / 30119

Importing a subversion repository where some branches come from trunk subtrees

Subject: Importing a subversion repository where some branches come from trunk subtrees

## tl;dr

3 messages between Mar 31, 2012 and Mar 31, 2012.

replies: 2people: 2as markdown or json

frnchfrgg.jr· Mar 31, 2012, 09:28 UTC · lore

Hello,

I noticed that a svn branch made out of a subtree of trunk confuses git-svn which fetches the whole history a second time (restricted to that subtree). Unfortunately this kind of strange branching has been repeatedly made in the Blender svn repository and I can end up with 5 or 6 times the full history from rev1 to rev20000, which makes the conversion even slower, the mirror bigger and loooong to clone and bisects completely unuseful.

Is this expected ? Or when git-svn identified the svn revision number of the parent and there already is a git commit imported from this revision, should it use that commit as the parent ? This would make the branch creation commit have a big "mangling paths" diff with its parent but I think it is logical.

That also means that when importing a revision, git-svn should always import the state of the whole tree (up to the branch, tag, or trunk root) and not only a part of it.

I have made a 4-revision sample svn repo which exhibits the problem, but it is quite simple to reproduce.

Is there a good reason for this behaviour (in other cases I can't think of) ?

Julien "_FrnchFrgg_" Rivaud

Andrew Sayers· Mar 31, 2012, 10:07 UTC · re: frnchfrgg.jr · lore

Re: Importing a subversion repository where some branches come from trunk subtrees

I'm not an expert on git-svn internals, but I believe sub-project branches are a limitation of its branching implementation. svn-fe doesn't have this problem at the downloading stage (and will do 20,000 revisions much quicker than git-svn), but requires you to split branches out by hand.

I'm currently trying to document these strange edge cases as part of an ongoing effort to add branch information on top of svn-fe's output. Would you mind taking a look at [1] and letting me know if it's an understandable description of your problem? Improvements and other edge cases are very much welcome, and I hope to have something in the coming months that tackles these issues.

	- Andrew

[1]https://github.com/andrew-sayers/SVN-Branching-Language/blob/master/t/advanced/subproject_branch.sh

Julien "_FrnchFrgg_" Rivaud· Mar 31, 2012, 10:23 UTC · re: Andrew Sayers · lore

Re: Importing a subversion repository where some branches come from trunk subtrees

On Sat, Mar 31, 2012 at 12:07 PM, Andrew Sayers <andrew-git@pileofstuff.org> wrote:

> Would you mind taking a look at [1] and letting me know if it's an
> understandable description of your problem?
> [1]https://github.com/andrew-sayers/SVN-Branching-Language/blob/master/t/advanced/subproject_branch.sh

Yes, it indeed is a good description of the action that causes git-svn to duplicate history (on the other hand, the cases I saw from the blender repo seem more like overlooks and/or straight mistakes)

_FrnchFrgg_