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.
Every exported macro needed to have all the macros used inside it:
1- to be exported as well.
2- be called from the `$crate` namespace so it works in other crates.
Some structs in `lightning::util::ser` needed to be made public as they were used inside the exported macros.
Use the macros like this:
```Rust
lightning::impl_writeable_tlv_based!(...)
```
BOLT 12 invoices may contain blinded_payinfo for each hop in a blinded
path. Each blinded_payinfo contains features, whose length must be
encoded since there may be multiple hops.
Note these features are also needed in the BOLT 4 encrypted_data_tlv
stream. But since they are a single TLV record, the length must *not* be
encoded there.
Most BOLT 12 features are used as the value of a TLV record and thus
don't use an explicit length. One exception is the features inside the
blinded payinfo subtype since the TLV record contains a list of them.
However, these features are also used in the BOLT 4 encrypted_data_tlv
TLV stream as a single record, where the length is implicit.
Implement Readable and Writeable for Features wrapped in WithoutLength
such that either serialization can be used where required.
Once ChannelManager supports payment retries, it will make more sense for its
current send_payment method to be named send_payment_with_route because
retrying should be the default. Here we get a head start on this by making the
rename in outbound_payment, but not changing the public interface yet.
