[PATCH v4 1/3] object-name: remove unreachable "unknown type" handling

Remove unreachable "unknown type" handling in the code that displays
the ambiguous object list. See [1] for the current output, and [1] for
the commit that added the "unknown type" handling.

The reason this code wasn't reachable is because we're not passing in
OBJECT_INFO_ALLOW_UNKNOWN_TYPE, so we'll die in sort_ambiguous()
before we get to show_ambiguous_object():

    $ git rev-parse 8315
    error: short object ID 8315 is ambiguous
    hint: The candidates are:
    fatal: invalid object type

We should do better here, but let's leave that for some future
improvement. In a subsequent commit I'll improve the output we do
show, and not having to handle the "unknown type" case simplifies that
change.

Even though we know that this isn't reachable let's back that up with
an assert() both for self-documentation and sanity checking.

1. 5cc044e0257 (get_short_oid: sort ambiguous objects by type,
   then SHA-1, 2018-05-10)
2. 1ffa26c461 (get_short_sha1: list ambiguous objects on error,
   2016-09-26)

Signed-off-by: Ævar Arnfjörð Bjarmason <redacted>
---
 object-name.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/object-name.c b/object-name.c
index fdff4601b2c..59e934262e7 100644
--- a/object-name.c
+++ b/object-name.c

@@ -361,6 +361,8 @@ static int show_ambiguous_object(const struct object_id *oid, void *data)
 		return 0;
 
 	type = oid_object_info(ds->repo, oid, NULL);
+	assert(type == OBJ_TREE || type == OBJ_COMMIT ||
+	       type == OBJ_BLOB || type == OBJ_TAG);
 	if (type == OBJ_COMMIT) {
 		struct commit *commit = lookup_commit(ds->repo, oid);
 		if (commit) {

@@ -376,8 +378,7 @@ static int show_ambiguous_object(const struct object_id *oid, void *data)
 
 	advise("  %s %s%s",
 	       repo_find_unique_abbrev(ds->repo, oid, DEFAULT_ABBREV),
-	       type_name(type) ? type_name(type) : "unknown type",
-	       desc.buf);
+	       type_name(type), desc.buf);
 
 	strbuf_release(&desc);
 	return 0;

-- 
2.34.0.822.gc64b680fd55