packfile: always populate pack-specific info when reading object info

When reading object information via `packed_object_info()` we may not
populate the object info's packfile-specific fields. This leads to
inconsistent object info depending on whether the info was populated via
`packfile_store_read_object_info()` or `packed_object_info()`.

Fix this inconsistency so that we can always assume the pack info to be
populated when reading object info from a pack.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pks-t

packfile.c

@@ -1657,6 +1657,20 @@ int packed_object_info(struct repository *r, struct packed_git *p,
 	}
 
 	oi->whence = OI_PACKED;
+	oi->u.packed.offset = obj_offset;
+	oi->u.packed.pack = p;
+
+	switch (type) {
+	case OBJ_REF_DELTA:
+		oi->u.packed.type = PACKED_OBJECT_TYPE_REF_DELTA;
+		break;
+	case OBJ_OFS_DELTA:
+		oi->u.packed.type = PACKED_OBJECT_TYPE_OFS_DELTA;
+		break;
+	default:
+		oi->u.packed.type = PACKED_OBJECT_TYPE_FULL;
+		break;
+	}
 
 out:
 	unuse_pack(&w_curs);
@@ -2156,23 +2170,6 @@ int packfile_store_read_object_info(struct packfile_store *store,
 		return -1;
 	}
 
-	if (oi->whence == OI_PACKED) {
-		oi->u.packed.offset = e.offset;
-		oi->u.packed.pack = e.p;
-
-		switch (rtype) {
-		case OBJ_REF_DELTA:
-			oi->u.packed.type = PACKED_OBJECT_TYPE_REF_DELTA;
-			break;
-		case OBJ_OFS_DELTA:
-			oi->u.packed.type = PACKED_OBJECT_TYPE_OFS_DELTA;
-			break;
-		default:
-			oi->u.packed.type = PACKED_OBJECT_TYPE_FULL;
-			break;
-		}
-	}
-
 	return 0;
 }