Re: [merge-tracking] record mergeinfo on wc to wc copy

On Sat, 29 Jul 2006, Madan S. wrote:
...
> As part of the merge-tracking tasks, we need to implement recording of
> mergeingo on cp.

Rather, we need to include "copyfrom" history when getting the merge
info for a path.

> This is needed because copy in itself is equivalent of
> merging 1-REV of the source into the target (where REV is the revision
> specified in the cp or the current revision of the wc)

The easiest way to implement this happens to be adding the merge
history and "revisions in existence" of a copy's source and setting
that as the "svn:mergeinfo" for its destination path.

I think 1-REV might not be correct, since very early revs might
represent an entirely different object which was moved to a subsequent
path in a later revision. Do we actually need to do some history
tracing here to find the oldest rev for our copy source?

> There are four ways a 'svn cp' can occur:
> - wc to wc
> - wc to repos
> - repos to wc
> - repos to repos
>
> As a first step, am planning to do the wc to wc part. Am thinking on
> the following lines:
>
> 1) Write a new function called append_wc_mergeinfo(target,
> new_mergeinfo), to prop_get the existing value of svn:mergeinfo on the
> target path, and to append/merge the provided mergeinfo and set the
> mergeinfo back into the target's svn:mergeinfo property.

You'll need both a 'propget' for "svn:mergeinfo" (to account for local
changes), plus a svn_ra_get_merge_info() to retrieve any inherited
merge info from parent directories stored in the repos.

We use/need a similar logic in libsvn_client/diff.c, so we'll want to
share code there.

> 2) Call append_wc_mergeinfo() in svn_wc_copy2() just before calling
> svn_wc_adm_close().

That looks like a likely spot to inject this behavior.

Do we need it to be "loggy"?