have not actually done a 'git update-index' on it yet - there is no
"object" associated with the new state, and you get:
- torvalds@ppc970:~/v2.6/linux> git diff-index HEAD
- *100644->100664 blob 7476bb......->000000...... kernel/sched.c
+ torvalds@ppc970:~/v2.6/linux> git diff-index --abbrev HEAD
+ :100644 100664 7476bb... 000000... kernel/sched.c
i.e., it shows that the tree has changed, and that `kernel/sched.c` has is
not up-to-date and may contain new stuff. The all-zero sha1 means that to