Instead of using the old variable name 'dotest' for
"$GIT_DIR"/rebase-merge and no variable for "$GIT_DIR"/rebase-apply,
introduce two variables 'merge_dir' and 'apply_dir' for these paths.
Signed-off-by: Martin von Zweigbergk <martin.von.zweigbergk@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>