We modified the setup_git_directory_gently_1() function earlier to make
it possible to discover the GIT_DIR without changing global state.
However, it is still a bit cumbersome to use if you only need to figure
out the (possibly absolute) path of the .git/ directory. Let's just
provide a convenient wrapper function with an easier signature that
*just* discovers the .git/ directory.
We will use it in a subsequent patch to fix the early config.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>