Our psbt input/output comparison functions use serialization to compare
the things, but if there's a map with things in it and the map isn't
sorted exactly the same, it's highly likely you'll mark an identical inputs
as different.
To fix this, we sort all the input/output maps before linearizing them.
There's no stable ordering on unknown serialization, so linearizing
identical but mis-ordered unknown data will lead to 'wrong' results.
Instead, we just ignore any data that's in the psbt unknown struct.
There's probably also problems here with other PSBT maps. Really, this
needs a finer grained comparison function .... fuck
includes facilities for
- sorting psbt inputs by serial_id
- sorting psbt outputs by serial_id
- adding a serial_id
- getting a serial_id
- finding the diffset between two psbts
- adding a max_len to a psbt input
- getting a max_len from a psbt input
