This is mainly just copying over the copy-editing from the
lightning-rfc repository.
[ Split to just perform changes prior to the UNKNOWN_PAYMENT_HASH change --RR ]
Signed-off-by: Christian Decker <decker.christian@gmail.com>
Reported-by: Rusty Russell <@rustyrussell>
This was suggested by Pierre-Marie as the solution to the 'same HTLC,
different CLTV' signature mismatch.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
It's just a sha256_double, but importantly when we convert it to a
string (in type_to_string, which is used in logging) we use
bitcoin_txid_to_hex() so it's reversed as people expect.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The wire protocol uses this, in the assumption that we'll never see feerates
in excess of 4294967 satoshi per kiloweight.
So let's use that consistently internally as well.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>