tree-diff: convert diff_root_tree_sha1() to just call diff_tree_sha1 with old=NULL

Now since diff_tree_sha1 understands NULL for both old and new, we could
indicate an empty tree for root commit by providing just NULL for old
sha1.

Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/tree-diff.c b/tree-diff.c
index b919983e96c4104d7a0667cbd009fe6d052d894b..11c3550177dbaab30596be2fc3c1633f2a0485f8 100644 (file)
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -311,18 +311,5 @@ int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const cha
 
 int diff_root_tree_sha1(const unsigned char *new, const char *base, struct diff_options *opt)
 {
 
 int diff_root_tree_sha1(const unsigned char *new, const char *base, struct diff_options *opt)
 {

-       int retval;
-       void *tree;
-       unsigned long size;
-       struct tree_desc empty, real;
-
-       tree = read_object_with_reference(new, tree_type, &size, NULL);
-       if (!tree)
-               die("unable to read root tree (%s)", sha1_to_hex(new));
-       init_tree_desc(&real, tree, size);
-
-       init_tree_desc(&empty, "", 0);
-       retval = diff_tree(&empty, &real, base, opt);
-       free(tree);
-       return retval;
+       return diff_tree_sha1(NULL, new, base, opt);

 }
 }