[PATCH] fsck.c: fix bogus "empty tree" check

ba002f3 (builtin-fsck: move common object checking code to fsck.c) did more than what it claimed to. Most notably, it wrongly made an empty tree object an error by pretending to only move code from fsck_tree() in builtin-fsck.c to fsck_tree() in fsck.c, but in fact adding a bogus check to barf on an empty tree.

An empty tree object is _unusual_. Recent porcelains try reasonably hard not to let the user create a commit that contains such a tree. Perhaps warning about them in git-fsck may have some merit.

However, being unusual and being errorneous are two quite different things. This is especially true now we seem to use the same fsck_$object() code in places other than git-fsck itself. For example, receive-pack should not reject unusual objects, even if it would be a good idea to tighten it to reject incorrect ones.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

 * I've wasted a few hours tonight hunting for random breakages in "git
   push", the symptom of which is "fatal: unresolved deltas left after
   unpacking."  I was hoping this patch would fix it, but it seems that
   the problem is elsewhere.

   I'll revert the following two commits for now:

   d5ef408 (unpack-objects: prevent writing of inconsistent objects)
   28f72a0 (receive-pack: use strict mode for unpacking objects)

   as I have verified that running with receive.fsckobjects set to false
   fixes the issues for me, and the repository at the receiving end (both
   before and after the push) pass git-fsck without problems.  Needless to
   say, I am not a happy camper right now.

 fsck.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)