revset: use `subset &` in `follow` This takes advantage of the `fullreposet` smartness. revset #0: follow(COPYING) 0) wall 0.002446 comb 0.000000 user 0.000000 sys 0.000000 (best of 735) 1) wall 0.000331 comb 0.000000 user 0.000000 sys 0.000000 (best of 5672)