difftool: don't assume that default sh is sane

diff --git a/object.c b/object.c
index 9c31e9a5e0e0d913044501089e09037e47894f03..69fbbbf504d861fac42ee50bc04a49ede1f60028 100644 (file)
--- a/object.c
+++ b/object.c
@@ -141,13 +141,12 @@ static void grow_object_hash(void)
        obj_hash_size = new_hash_size;
 }
 
-void *create_object(const unsigned char *sha1, int type, void *o)
+void *create_object(const unsigned char *sha1, void *o)
 {
        struct object *obj = o;
 
        obj->parsed = 0;
        obj->used = 0;
-       obj->type = type;
        obj->flags = 0;
        hashcpy(obj->sha1, sha1);
 
@@ -159,11 +158,30 @@ void *create_object(const unsigned char *sha1, int type, void *o)
        return obj;
 }
 
+void *object_as_type(struct object *obj, enum object_type type, int quiet)
+{
+       if (obj->type == type)
+               return obj;
+       else if (obj->type == OBJ_NONE) {
+               if (type == OBJ_COMMIT)
+                       ((struct commit *)obj)->index = alloc_commit_index();
+               obj->type = type;
+               return obj;
+       }
+       else {
+               if (!quiet)
+                       error("object %s is a %s, not a %s",
+                             sha1_to_hex(obj->sha1),
+                             typename(obj->type), typename(type));
+               return NULL;
+       }
+}
+
 struct object *lookup_unknown_object(const unsigned char *sha1)
 {
        struct object *obj = lookup_object(sha1);
        if (!obj)
-               obj = create_object(sha1, OBJ_NONE, alloc_object_node());
+               obj = create_object(sha1, alloc_object_node());
        return obj;
 }
 
@@ -214,8 +232,6 @@ struct object *parse_object_buffer(const unsigned char *sha1, enum object_type t
                warning("object %s has unknown type id %d", sha1_to_hex(sha1), type);
                obj = NULL;
        }
-       if (obj && obj->type == OBJ_NONE)
-               obj->type = type;
        return obj;
 }