Asking whether the merge contains the held commit refused forward merges
forever on a diverged or rewritten main or a squash-merged registered head,
failed every later merge when the forge no longer had the held commit, and
cost one forge call per held commit. The question is now the reverse: a merge
is kept back only when it is in the taken merge and differs from it. A merged
message asks it once, before it writes anything, and a late message writes no
module, deletion, placement or taken key. A take-in asks it once for its
module. A 404 is not known to be older and is written, and said; any other
failure to say leaves the message for redelivery.
jschoubben
743a3618ea