Merge rename tracking

Folker Schamel <schamel23 <at> spinor.com> writes:
> We came accross that issue because currently we have a long living branch.
> We regulary merge from trunk (having trivial scripts managing
> the last merged revision).
> And due to refactoring, several files are renamed in the branch.
> So we encountered that issue.

Actually you can use svk to do the merge. Just add a depot map, say
'project', to the existing subversion repository, and run

    svk merge -rN:M --track-rename /project/trunk /project/branches/mybranch

This is also how I generate the perl bindings backport patch for 1.0.x
branch, since there were reorganization of the tree some while ago.

There is no rename tracking support for 'svk smerge' yet, because the
ancestor and source can be on different branches, and there's
currently no way to inject rename information for svn_repos_dir_delta.

Why is --track-renmae not default? Because it's an expensive
operation. svk has to harvest renames up to last merge points with
svn_fs_node_history, and see if any of the ancestors are deleted in
the same revision. Yes, there's no true rename support, but that's
what we have now.

ghudson said on IRC that it is possible to add APIs to extract copy
ancestors efficiently without schema changes. We definitely need this
as a prerequisite for proper merge support in svn.

Cheers,
CLK