ACK 277be22

All the per-input fields have _IN_ in their names, but these new fields do not. Why ?

I regret not having a watch turned on the bip repo, so I'm late with my comments, this is already merged.

But IMO it would be better to have one new field, PSBT_IN_UNLOCKDATA, and a byte that specifies the type of unlock, PSBT_UNLOCKDATA_PREIMAGE_SHA256, etc. Or PSBT_IN_HASH_PREIMAGE and four types of hashes.

As I understand, there's no reason to have several preimages of different type for a single input. Thus having them in different fields creates ambiguity. Should having both SHA256 and RIPEMD160 preimages be treated as error ?

@dgpv you can certainly have different kinds of preimages in one input (or multiple of a single kind of preimage)

As for the names missing _IN_, I think we should fix this. Good catch. I will open another PR.

@apoelstra, what happened to the (c) part from https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-March/016720.html ?

(c) a map from public keys to 32-byte "tweaks" that are used in the pay-to-contract construction

I also see no PR for it being opened...