Re: [PATCH 2/3] merge-recursive: add ability to turn off directory rename detection

[Elijah Newren <newren@gmail.com>]

On Wed, Aug 29, 2018 at 5:54 AM Johannes Schindelin
<Johannes.Schindelin@gmx.de> wrote:
>
> Hi Elijah,
>
> On Wed, 29 Aug 2018, Elijah Newren wrote:
>
> > Signed-off-by: Elijah Newren <newren@gmail.com>
> > ---
> >  merge-recursive.c | 18 +++++++++++++-----
> >  merge-recursive.h |  1 +
> >  2 files changed, 14 insertions(+), 5 deletions(-)
> >
> > diff --git a/merge-recursive.c b/merge-recursive.c
> > index f110e1c5ec..bf3cb03d3a 100644
> > --- a/merge-recursive.c
> > +++ b/merge-recursive.c
> > @@ -2843,12 +2843,19 @@ static int handle_renames(struct merge_options *o,
> >       head_pairs = get_diffpairs(o, common, head);
> >       merge_pairs = get_diffpairs(o, common, merge);
> >
> > -     dir_re_head = get_directory_renames(head_pairs, head);
> > -     dir_re_merge = get_directory_renames(merge_pairs, merge);
> > +     if (o->detect_directory_renames) {
> > +             dir_re_head = get_directory_renames(head_pairs, head);
> > +             dir_re_merge = get_directory_renames(merge_pairs, merge);
> >
> > -     handle_directory_level_conflicts(o,
> > -                                      dir_re_head, head,
> > -                                      dir_re_merge, merge);
> > +             handle_directory_level_conflicts(o,
> > +                                              dir_re_head, head,
> > +                                              dir_re_merge, merge);
> > +     } else {
> > +             dir_re_head  = xmalloc(sizeof(*dir_re_head));
> > +             dir_re_merge = xmalloc(sizeof(*dir_re_merge));
>
> This is not a suggestion to change anything, but a genuine question out of
> curiosity: would it make sense to put the `dir_re_head` and `dir_re_merge`
> structures into `struct merge_options` to avoid these extra `malloc()`s?
> Or would that cause issues with the recursive nature of the recursive
> merge?

That would work to avoid the extra `malloc()`s, and be inline with the
current usage of merge_options.  However, I'm not sure I like the
current usage of merge_options. That struct is supposed to be public
API, but it's got a lot of private internal-only use stuff (and
putting dir_re_head and dir_re_merge there would add more).  I'm
tempted to go the other way and eject some of the other internal-only
stuff from merge_options (or wrap it inside an opaque struct
merge_options_internal* internal field, or something like that).