ref: 1f7d3cfc2d7cc9067fb4b1be56cedd6332c2663e 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