ref: f5fd3ab0d6e3fa3c2b7a6a0bc20c5444c7ba8ab9 dir: /sys/src/cmd/diff/test/merge-t3.expected/
1 2 3 4 <<<<<<<<<< merge-t3.l y ========== original 5 ========== merge-t3.r x >>>>>>>>>> 6 7 8 9 10