* 'jn/maint-setup-fix' (early part):
Revert "rehabilitate 'git index-pack' inside the object store"
setup: do not forget working dir from subdir of gitdir
t4111 (apply): refresh index before applying patches to it
setup: split off get_device_or_die helper
setup: split off a function to handle hitting ceiling in repo search
setup: split off code to handle stumbling upon a repository
setup: split off a function to checks working dir for .git file
setup: split off $GIT_DIR-set case from setup_git_directory_gently
tests: try git apply from subdir of toplevel
t1501 (rev-parse): clarify