ref: 5ba6c22fafed27542b105dc293371d2b1a1c8a1d dir: /sys/src/cmd/diff/test/merge-t5.expected/
1 a b c 2 3 <<<<<<<<<< merge-t5.l 4 x 6 7 ========== original 4 5 6 7 ========== merge-t5.r w x y z >>>>>>>>>> 8 9 10