Jeff King [off-list ref] writes:
Heh. I wonder if I was too optimistic in my review at:
https://lore.kernel.org/git/YHCYfeRsHU34ZF%2Fl@coredump.intra.peff.net/ (local)
Yes, merging is hard. When merging a topic X into 'seen', I can
review "log -p ..MERGE_HEAD" and keep the core changes the topic
wants to do in my head while reviewing the conflicting parts, but
this is the other "log -p MERGE_HEAD.." direction where all the
little cuts _other_ topics inflicted on the codebase before an
attempted merge, and something seemingly benign and well intended
change like "well nobody passes -1 to ask us to count _now_, so
let's drop the feature without even bothering to check nobody does
so in the future" can easily be missed.