Merge branch 'jk/empty-tree'

* jk/empty-tree:
  add--interactive: handle initial commit better
  hard-code the empty tree object

diff --combined sha1_file.c
index d9da7c8f75c8f44a62661d92b6f8e5266df83a73,f7b75b2acc1f52775d70f94fa20c0ca98b8f58c9..1ddb96bb82b60f4da8489664d13f398d88bf5a15
--- 1/sha1_file.c
--- 2/sha1_file.c
+++ b/sha1_file.c
@@@ -1845,6 -1845,15 +1845,15 @@@ static struct cached_object 
  } *cached_objects;
  static int cached_object_nr, cached_object_alloc;
  
+ static struct cached_object empty_tree = {
+       /* empty tree sha1: 4b825dc642cb6eb9a060e54bf8d69288fbee4904 */
+       "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60"
+       "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04",
+       OBJ_TREE,
+       "",
+       0
+ };
+ 
  static struct cached_object *find_cached_object(const unsigned char *sha1)
  {
        int i;
@@@ -1854,6 -1863,8 +1863,8 @@@
                if (!hashcmp(co->sha1, sha1))
                        return co;
        }
+       if (!hashcmp(sha1, empty_tree.sha1))
+               return &empty_tree;
        return NULL;
  }
  
@@@ -1943,8 -1954,7 +1954,8 @@@ void *read_object_with_reference(const 
                }
                ref_length = strlen(ref_type);
  
 -              if (memcmp(buffer, ref_type, ref_length) ||
 +              if (ref_length + 40 > isize ||
 +                  memcmp(buffer, ref_type, ref_length) ||
                    get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
                        free(buffer);
                        return NULL;
@@@ -2359,8 -2369,7 +2370,8 @@@ int index_fd(unsigned char *sha1, int f
        if ((type == OBJ_BLOB) && S_ISREG(st->st_mode)) {
                struct strbuf nbuf;
                strbuf_init(&nbuf, 0);
 -              if (convert_to_git(path, buf, size, &nbuf)) {
 +              if (convert_to_git(path, buf, size, &nbuf,
 +                                 write_object ? safe_crlf : 0)) {
                        munmap(buf, size);
                        buf = strbuf_detach(&nbuf, &size);
                        re_allocated = 1;