t / t4013 / diff.rev-list_--children_HEADon commit merge-octopus: abort if index does not match HEAD (3ec62ad)
   1$ git rev-list --children HEAD
   259d314ad6f356dd08601a4cd5e530381da3e3c64
   3c7a2ab9e8eac7b117442a607d5a9b3950ae34d5a 59d314ad6f356dd08601a4cd5e530381da3e3c64
   49a6d4949b6b76956d9d5e26f2791ec2ceff5fdc0 59d314ad6f356dd08601a4cd5e530381da3e3c64
   51bde4ae5f36c8d9abe3a0fce0c6aab3c4a12fe44 9a6d4949b6b76956d9d5e26f2791ec2ceff5fdc0
   6444ac553ac7612cc88969031b02b3767fb8a353a 1bde4ae5f36c8d9abe3a0fce0c6aab3c4a12fe44 c7a2ab9e8eac7b117442a607d5a9b3950ae34d5a
   7$