It's not ideal to do all this computation while the lock is held. We also want
to decode the failure *before* taking the lock, so we can store the failed scid
in the relevant outbound for retry in the next commit(s).
Secrets should not be exposed in-memory at the interface level as it
would be impossible the implement it against a hardware security
module/secure element.
We have a number of debug assertions which are expected to never
fire when running in a single thread. This is just fine in tests,
and gives us good coverage of our lockorder requirements, but is
not-irregularly surprising to users, who may run with their own
debug assertions in test environments.
Instead, we gate these checks by the `cfg(test)` setting as well as
the `_test_utils` feature, ensuring they run in our own tests, but
not downstream tests.
In the next commit(s) we'll start holding `ChannelMonitorUpdate`s
that are being persisted in `Channel`s until they're done
persisting. In order to do that, switch to applying the updates by
reference instead of value.
This fixes a crash in the `full_stack_target` fuzz test (found by
Chaincode's generous fuzzing infrastructure!) but ultimately is a
better error code - a peer disconnecting before we can fund a
channel isn't a "misuse error" its an unavailable channel.
In newer versions of `hashbrown` this code would be broken. While
we aren't updating `hashbrown` any time soon (as it requires an
MSRV bump), it is useful to swap for a newer `hashbrown` when
fuzzing, which this makes easier.
This is purely a refactor that does not change the InitFeatures
advertised by a ChannelManager. This allows users to configure which
features should be advertised based on the values of `UserConfig`. While
there aren't any existing features currently leveraging this behavior,
it will be used by the upcoming anchors_zero_fee_htlc_tx feature.
The UserConfig dependency on provided_init_features caused most
callsites of the main test methods responsible for opening channels to
be updated. This commit foregos that completely by no longer requiring
the InitFeatures of each side to be provided to these methods. The
methods already require a reference to each node's ChannelManager to
open the channel, so we use that same reference to obtain their
InitFeatures. A way to override such features was required for some
tests, so a new `override_init_features` config option now exists on
the test harness.
