hard-code the empty tree object

Now any commands may reference the empty tree object by its sha1 (4b825dc642cb6eb9a060e54bf8d69288fbee4904). This is useful for showing some diffs, especially for initial commits. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Feb 13, 2008 at 06:25 UTC 346245a1bb6272dd370ba2f7b9bf86d3df5fed9a

1 file changed +11

sha1_file.c

+11

@@ -1845,6 +1845,15 @@ static struct cached_object {

1845 } *cached_objects;

1846 static int cached_object_nr, cached_object_alloc;

1847

1848 +static struct cached_object empty_tree = {

1849 + /* empty tree sha1: 4b825dc642cb6eb9a060e54bf8d69288fbee4904 */

1850 + "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60"

1851 + "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04",

1852 + OBJ_TREE,

1853 + "",

1854 + 0

1855 +};

1856 +

1857 static struct cached_object *find_cached_object(const unsigned char *sha1)

1858 {

1859 int i;

@@ -1854,6 +1863,8 @@ static struct cached_object *find_cached_object(const unsigned char *sha1)

1863 if (!hashcmp(co->sha1, sha1))

1864 return co;

1865 }

1866 + if (!hashcmp(sha1, empty_tree.sha1))

1867 + return &empty_tree;

1868 return NULL;

1869 }

1870