We don't preserve detailed asset information at the moment, so provide a
way to convert from a sat to an amount_asset struct.
We also need a way to convert from an 'amount_asset' to a 'value' for
elements, which for explicit (i.e. non-blinded) asssets is a 0x01 prefix
plus the big-endian encoded value.
Our existing coin_moves tracking logic assumed that any tx we had an
input in belonged to *all* of our wallet (not a bad assumption as long
as there was no way to update a tx that spends our wallets)
Now that we've got `signpsbt` implemented, however, we need to be
careful about how we account for withdrawals. For now we do a best guess
at what the feerate is, and lump all of our spent outputs as a
'withdrawal' when it's impossible to disambiguate
It returns NULL, so you can simply `return fromwire_fail(...)`
if you want to return NULL in this case. Use that more.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We did this originally because these types are referred to in the bolts, and we
had no way of injecting the correct include lines into those. Now we do, so
there's less excuse for this.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We often want a pointer which will turn to NULL if the pointed-to thing is
freed. This is possible with tal objects, so create it.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
