When I read the RETURN VALUE the first time, I didn't realize this command produces (or recreates) the psbt that I need. The change I made makes that more obvious when it's presented as a hit by GH for a search for psbt.
[ Generated man page --RR ]
In the case where you want a PSBT and also want the output to be added
as a change address, use `excess_as_change` = true.
Generates a change address to use. If you want to pay the excess
elsewhere, you will have to add separately.
Changelog-Added: JSON-RPC: Add new parameter `excess_as_change` to fundpsbt+utxopsbt
Needed for v2 of channel opens, where the minimum weight is 110; a
'simple utxo' (sig + key) weighs in at 107, so we a need a way to
establish a floor for this case.
Changelog-Added: JSON-RPC: fundpsbt/utxopsbt have new param, `min_witness_utxo`, which sets a floor for the weight calculation of an added input
This should be more robust in future: we SHA256 all of the deps.
For wiregen we prefix with EXPERIMENTAL_FEATURES, since it can effect them.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This more closely mirrors fundpsbt (which will only select unreserved ones)
but you can turn it off if you want to e.g. rbf in future.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Added: JSON-RPC: New low-level command `utxopsbt` to create PSBT from existing utxos.
It's *possible* to do this using various RPC calls, but it's
unfriendly:
1. Call getinfo to get the current block height.
2. Call listfunds to map the UTXOs.
3. Create the PSBT and hope you get all the fields correct.
Instead, this presents an interface just like `fundpsbt`, with identical
returns.
I think it's different enough to justify a new command (though it
shares much internally, of course).
In particular, it's now quite simple to create a command which uses
specified utxos, and then adds more to meet any shortfall.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
