Julian Foad wrote on Wed, Jun 12, 2013 at 12:22:31 +0100:
> Daniel Shahaf wrote:
>
> > danie...@apache.org wrote on Wed, Jun 12, 2013 at 10:29:35 -0000:
> >> Author: danielsh
> >> Date: Wed Jun 12 10:29:34 2013
> >> New Revision: 1492134
> >>
> >> URL: http://svn.apache.org/r1492134
> >> Log:
> >> Add an XFail test for 'svn blame -r 3:1' (where 3 > 1).
> >>
> >> Not filing an issue since I plan to commit a fix soon.
>
> What behaviour change are you planning for 'blame'?
>
> I ask because I don't think it's obvious.
>
> For example, it would be useful to have a mode that looks forward in
> time from a given revision, to find the *next* revision at which each
> line is changed after the starting revision. Is that the behaviour
> you are planning?
>
What I was thinking was to allow blame to consider the sequence of
revisions in opposite order: instead of considering the oldest revision
the first one in the chain, so `svn blame` output prints the youngest
revision that touched a given line, allow 'svn blame' (when invoked as
-r M:N with M<N, which is currently an error) to consider the _youngest_
revision as the first one in the chain, so that `svn blame` output will
print the _oldest_ revision that touched a given line.
In other words: 'svn blame -r 3:1 iota' will, for each line in iota@1,
print the oldest revision which changed or removed that line.
Does that make sense?
Thanks for asking,
Daniel
> - Julian
>
>
> > Update: Bert found a potential problem with peg revisions here that
> > might require revving an RA API, so it'll take me longer to get to
> > committing a fix than I planned.
> >
> > Current WIP patch:
> >
> > Index: subversion/libsvn_client/blame.c
> > ===================================================================
> > --- subversion/libsvn_client/blame.c (revision 1492120)
> > +++ subversion/libsvn_client/blame.c (working copy)
> > @@ -466,7 +466,7 @@ file_rev_handler(void *baton, const char *path, sv
> > /* Create the rev structure. */
> > frb->rev = apr_pcalloc(frb->mainpool, sizeof(struct rev));
> >
> > - if (revnum < frb->start_rev)
> > + if (revnum < MIN(frb->start_rev, frb->end_rev))
> > {
> > /* We shouldn't get more than one revision before the starting
> > revision (unless of including merged revisions). */
> > @@ -479,7 +479,8 @@ file_rev_handler(void *baton, const char *path, sv
> > }
> > else
> > {
> > - SVN_ERR_ASSERT(revnum <= frb->end_rev);
> > + /* 1+ for the "youngest to oldest" blame */
> > + SVN_ERR_ASSERT(revnum <= 1 + MAX(frb->end_rev, frb->start_rev));
> >
> > /* Set values from revision props. */
> > frb->rev->revision = revnum;
> > @@ -578,6 +579,7 @@ svn_client_blame5(const char *target,
> > svn_stream_t *last_stream;
> > svn_stream_t *stream;
> > const char *target_abspath_or_url;
> > + svn_revnum_t youngest;
> >
> > if (start->kind == svn_opt_revision_unspecified
> > || end->kind == svn_opt_revision_unspecified)
> > @@ -599,11 +601,6 @@ svn_client_blame5(const char *target,
> > target_abspath_or_url,
> > ra_session,
> > start, pool));
> >
> > - if (end_revnum < start_revnum)
> > - return svn_error_create
> > - (SVN_ERR_CLIENT_BAD_REVISION, NULL,
> > - _("Start revision must precede end revision"));
> > -
> > /* We check the mime-type of the yougest revision before getting all
> > the older revisions. */
> > if (!ignore_mime_type)
> > @@ -674,8 +671,14 @@ svn_client_blame5(const char *target,
> > We need to ensure that we get one revision before the start_rev,
> > if available so that we can know what was actually changed in the
> > start
> > revision. */
> > + SVN_ERR(svn_ra_get_latest_revnum(ra_session, &youngest, frb.currpool));
> > SVN_ERR(svn_ra_get_file_revs2(ra_session, "",
> > - start_revnum - (start_revnum > 0 ? 1 : 0),
> > + start_revnum
> > + - (0 < start_revnum && start_revnum
> > < end_revnum ? 1 : 0)
> > + + (youngest > start_revnum &&
> > start_revnum > end_revnum ? 1 : 0),
> > + /* ### pass MAX(start_revnum, end_revnum)
> > as
> > peg thru to svn_fs_revision_root() */
> > + /* ### blame 5 fails. */
> > + /* ### check svn_repos_get_file_revs2
> > tests. */
> > end_revnum, include_merged_revisions,
> > file_rev_handler, &frb, pool));
> >
> >
> >> * subversion/tests/cmdline/blame_tests.py
> >> (blame_youngest_to_oldest): New test, XFail.
> >> (test_list): Run it.
> >
