[PATCH] Fix install-doc-quick target

The script starts in a subdirectory of the source directory to muck with a branch whose structure does not have anything to do with the actual work tree. Go up to the top to make it clear that we operate on the whole tree.

It also exported GIT_DIR without any good reason.  Remove it.

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

 * I am getting the impression that the semantics of the updated
   work-tree support is as broken as the original, although the
   code that implements it is easier to read.  

   Admittedly, this is an unorthodox corner case usage, that
   deals with a tree structure that does not have any relation
   with the current project state, and the script is started
   with a subdirectory of the current project.  What is needed
   is a way to tell git that "we may be in a subdirectory but
   the tree structure we are dealing with does not have anything
   to do with the current work tree structure -- ignore the fact
   that we are not at the toplevel", and exporting of GIT_DIR
   was the way to do so in the old world order.

   Another way to do this in the new world order would be to
   pass "--work-tree=.", but this has its own problems it
   seems.  You can try commenting out cd_to_toplevel this patch
   introduces, then rewrite checkout-index part with:

    git --git-dir="$GIT_DIR" --work-tree=. checkout-index -a...

   which seems to work, but if you drop --git-dir="$GIT_DIR"
   from the above (without reintroducing the export of GIT_DIR),
   you get "fatal: Could not switch to '.git'" which seems quite
   bogus.  If you say:

	git --work-tree=. foo

   without saying anything about GIT_DIR, shouldn't we run the
   usual .git/ discovery, going up the directories? 

 Documentation/install-doc-quick.sh |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)