t / t3901-utf8.txton commit diff.c: the builtin_diff() deals with only two-file comparison (b8d9c1a)
   1: to be sourced in t3901 -- this is utf8
   2GIT_AUTHOR_NAME="Áéí óú" &&
   3GIT_COMMITTER_NAME=$GIT_AUTHOR_NAME &&
   4export GIT_AUTHOR_NAME GIT_COMMITTER_NAME