Re: svn commit: r1577144 - /subversion/trunk/subversion/libsvn_ra/compat.c

On 13 March 2014 17:13, Branko Čibej <brane_at_wandisco.com> wrote:
> On 13.03.2014 13:53, ivan_at_apache.org wrote:
>
> Author: ivan
> Date: Thu Mar 13 12:53:40 2014
> New Revision: 1577144
>
> URL: http://svn.apache.org/r1577144
> Log:
> Fix problem exposed by r1577079.
>
> * subversion/libsvn_ra/compat.c
> (svn_ra__locations_from_log): Make a copy of constant apr_array_header_t
> argument before sorting it.
>
>
> [...]
>
>
> @@ -337,10 +338,11 @@ svn_ra__locations_from_log(svn_ra_sessio
> /* Figure out the youngest and oldest revs (amongst the set of
> requested revisions + the peg revision) so we can avoid
> unnecessary log parsing. */
> - svn_sort__array(location_revisions, compare_revisions);
> - oldest_requested = APR_ARRAY_IDX(location_revisions, 0, svn_revnum_t);
> - youngest_requested = APR_ARRAY_IDX(location_revisions,
> - location_revisions->nelts - 1,
> + sorted_location_revisions = apr_array_copy(pool, location_revisions);
> + svn_sort__array(sorted_location_revisions, compare_revisions);
> + oldest_requested = APR_ARRAY_IDX(sorted_location_revisions, 0,
> svn_revnum_t);
> + youngest_requested = APR_ARRAY_IDX(sorted_location_revisions,
> + sorted_location_revisions->nelts - 1,
> svn_revnum_t);
> youngest = peg_revision;
> youngest = (oldest_requested > youngest) ? oldest_requested : youngest;
> @@ -352,7 +354,7 @@ svn_ra__locations_from_log(svn_ra_sessio
> /* Populate most of our log receiver baton structure. */
> lrb.kind = kind;
> lrb.last_path = fs_path;
> - lrb.location_revisions = apr_array_copy(pool, location_revisions);
> + lrb.location_revisions = apr_array_copy(pool, sorted_location_revisions);
>
>
> So now you've copied the array twice?
>
Yes, I do. Because lrb.locations_revisions will be modified by
svn_ra_get_log3() callback, while we need unmodified and sorted
location revisions if the received log information did not cover any
of the requested revisions:
[[[
  if (! lrb.peg_path)
    lrb.peg_path = lrb.last_path;
  if (lrb.last_path)
    {
      int i;
      for (i = 0; i < sorted_location_revisions->nelts; i++)
        {
          svn_revnum_t rev = APR_ARRAY_IDX(sorted_location_revisions, i,
                                           svn_revnum_t);
          if (! apr_hash_get(locations, &rev, sizeof(rev)))
            apr_hash_set(locations, apr_pmemdup(pool, &rev, sizeof(rev)),
                         sizeof(rev), apr_pstrdup(pool, lrb.last_path));
        }
    }
]]]

So I decided to just copy it twice given that this is fallback code
for older servers and don't covered by our test suite.

-- 
Ivan Zhakov