t / t3901-utf8.txton commit bundle: fix wrong check of read_header()'s return value & add tests (8315588)
   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