ref: b73d0d12fb1a274f854e7aa24bd3f35bebcc98a2 dir: /sys/src/cmd/diff/test/merge-t4.expected/
1 2 3 <<<<<<<<<< merge-t4.l 4 x 6 7 ========== original 4 5 6 7 ========== merge-t4.r w x y z >>>>>>>>>> 8 9 10