It's hard to say what's the safest thing to do when we get an ack we
weren't expecting due to losing outstanding.agents.state in +load
3-to-4, so this gives both a watch-ack and a poke-ack. This seems most
likely to succeed.
Does not change state type, but clears outstanding.agents.state since
it's full of garbage values. This introduces a possibility that we may
have been in the middle of something, so we handle that in a reasonably
sane way.
outstanding.agents.state is a queue of what sort of message we sent to a
foreign app. We use it so that when the acknowledgment comes back we
know whether to treat it as a watch-ack, poke-ack, or neither. We used
to put this info in the wire, but this gave us a different ames flow,
which meant %leave and %watch didn't get associated (causing #2079).
The error was that when when retrieving the item from the queue, we put
the new 1-item-shorter queue back in outstanding.agents.state at a
different wire than it came from, so the queues never actually got
shorter, and acknowledgments of the wrong sort were commonly produced.
This caused problems mainly in situations where we poke and peer on the
same wire, and possibly when a subscription was cancelled.
Possibly related to #2206 and #2176. I would expect this bug to cause
those issues, but I haven't verified the converse. Also possibly
related to #2153 and #2079.
"Replace" suggests this function either produces an updated set/map when done,
like +snap, or changes all values in-place, like +turn. In truth, it's more
similar to +roll, which does reduction/accumulation.
("Reduce" specifically was chosen because it maintains the mnemonic relation to
the arm name.)
It's very easy to forget to verify that pills have been updated
accordingly when the kernel changes. This adds a warning that prints
when the kernel in the target has changed but the pills have not.
Also prompts the user for confirmation pre-merge.
The scaffold and reducer work thus far had some bugs and shims. This commit
adds the parameters, API calls and fixes the reducers for the two
features.
