On 2023-10-24 at 20:12:52, Eric Sunshine wrote:
> On Tue, Oct 24, 2023 at 3:58 PM brian m. carlson
> <sandals@crustytoothpaste.net> wrote:
> > git merge-file knows how to merge files on the file system already.  It
> > would be helpful, however, to allow it to also merge single blobs.
> > Teach it an `--object-id` option which means that its arguments are
> > object IDs and not files to allow it to do so.
> >
> > Since we obviously won't be writing the data to the first argument,
> > either write to the object store and print the object ID, or honor the
> > -p argument and print it to standard out.
> >
> > We handle the empty blob specially since read_mmblob doesn't read it
> > directly, instead throwing an error, and otherwise users cannot specify
> > an empty ancestor.
> >
> > Signed-off-by: brian m. carlson <bk2204@github.com>
> > ---
> > diff --git a/builtin/merge-file.c b/builtin/merge-file.c
> > @@ -99,20 +116,29 @@ int cmd_merge_file(int argc, const char **argv, const char *prefix)
> >         if (ret >= 0) {
> > -               const char *filename = argv[0];
> > -               char *fpath = prefix_filename(prefix, argv[0]);
> > -               FILE *f = to_stdout ? stdout : fopen(fpath, "wb");
> > +               if (object_id && !to_stdout) {
> > +                       struct object_id oid;
> > +                       if (result.size)
> > +                               write_object_file(result.ptr, result.size, OBJ_BLOB, &oid);
> 
> Should this be caring about errors by checking the return value of
> write_object_file()?

Probably so.  I think I saw write_object_file_prepare returned void and
misinterpreted that as write_object_file returning void.
-- 
brian m. carlson (he/him or they/them)
Toronto, Ontario, CA