This appears in listsendpays / listpays, and is useful information (if we know!).
This doesn't fix old payments, but means that xpay can use this for new payments.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I used an unknown arg and it didn't complain. injectpaymentonion's schema predated
the sweep which fixed up use of "additionalProperties".
Indeed, we were missing some properties!
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is like `sendonion` but unwraps the onion as the first hop,
avoiding nasty special cases for blinded paths which start with this
node, and also self-pay.
Tests split into multiple ones after Christian's review.
Changelog-Added: JSON-RPC: `injectpaymentonion` for initiating an HTLC like a peer would do.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
