Drop `amount_msats` from `InvoiceRequestFields`

An `InvoiceRequest` can overpay for an `Offer` which would be
reflected back to the recipient via the `amount_msats` field, but
its somewhat deceptive as the sender can *also* then further
overpay in the HTLC(s) themselves. The total overpayment is already
communicated in the `Event::ClaimablePayment` so we simply drop the
`InvoiceRequestFields` field here.

Fixes #3002

diff --git a/lightning/src/ln/offers_tests.rs b/lightning/src/ln/offers_tests.rs
index 75a2e290f39e824514fdaa3b6333eb20b319663e..5a6285373846f1e3cf92a306b71cb67a4ebdb3b0 100644 (file)
--- a/lightning/src/ln/offers_tests.rs
+++ b/lightning/src/ln/offers_tests.rs
@@ -412,7 +412,6 @@ fn creates_and_pays_for_offer_using_two_hop_blinded_path() {
                offer_id: offer.id(),
                invoice_request: InvoiceRequestFields {
                        payer_id: invoice_request.payer_id(),
-                       amount_msats: None,
                        features: InvoiceRequestFeatures::empty(),
                        quantity: None,
                        payer_note_truncated: None,
@@ -565,7 +564,6 @@ fn creates_and_pays_for_offer_using_one_hop_blinded_path() {
                offer_id: offer.id(),
                invoice_request: InvoiceRequestFields {
                        payer_id: invoice_request.payer_id(),
-                       amount_msats: None,
                        features: InvoiceRequestFeatures::empty(),
                        quantity: None,
                        payer_note_truncated: None,
@@ -687,7 +685,6 @@ fn pays_for_offer_without_blinded_paths() {
                offer_id: offer.id(),
                invoice_request: InvoiceRequestFields {
                        payer_id: invoice_request.payer_id(),
-                       amount_msats: None,
                        features: InvoiceRequestFeatures::empty(),
                        quantity: None,
                        payer_note_truncated: None,

diff --git a/lightning/src/offers/invoice_request.rs b/lightning/src/offers/invoice_request.rs
index 9157613fcd977a132e9f7b5751f196af0592269a..dcc6394153fb169f80924aa8d6fdf39840eff4a7 100644 (file)
--- a/lightning/src/offers/invoice_request.rs
+++ b/lightning/src/offers/invoice_request.rs
@@ -877,13 +877,12 @@ impl VerifiedInvoiceRequest {
                let InvoiceRequestContents {
                        payer_id,
                        inner: InvoiceRequestContentsWithoutPayerId {
-                               payer: _, offer: _, chain: _, amount_msats, features, quantity, payer_note
+                               payer: _, offer: _, chain: _, amount_msats: _, features, quantity, payer_note
                        },
                } = &self.inner.contents;
 
                InvoiceRequestFields {
                        payer_id: *payer_id,
-                       amount_msats: *amount_msats,
                        features: features.clone(),
                        quantity: *quantity,
                        payer_note_truncated: payer_note.clone()
@@ -1126,12 +1125,6 @@ pub struct InvoiceRequestFields {
        /// A possibly transient pubkey used to sign the invoice request.
        pub payer_id: PublicKey,
 
-       /// The amount to pay in msats (i.e., the minimum lightning-payable unit for [`chain`]), which
-       /// must be greater than or equal to [`Offer::amount`], converted if necessary.
-       ///
-       /// [`chain`]: InvoiceRequest::chain
-       pub amount_msats: Option<u64>,
-
        /// Features pertaining to requesting an invoice.
        pub features: InvoiceRequestFeatures,
 
@@ -1150,7 +1143,6 @@ impl Writeable for InvoiceRequestFields {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
                write_tlv_fields!(writer, {
                        (0, self.payer_id, required),
-                       (2, self.amount_msats.map(|v| HighZeroBytesDroppedBigSize(v)), option),
                        (4, WithoutLength(&self.features), required),
                        (6, self.quantity.map(|v| HighZeroBytesDroppedBigSize(v)), option),
                        (8, self.payer_note_truncated.as_ref().map(|s| WithoutLength(&s.0)), option),
@@ -1163,7 +1155,6 @@ impl Readable for InvoiceRequestFields {
        fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
                _init_and_read_len_prefixed_tlv_fields!(reader, {
                        (0, payer_id, required),
-                       (2, amount_msats, (option, encoding: (u64, HighZeroBytesDroppedBigSize))),
                        (4, features, (option, encoding: (InvoiceRequestFeatures, WithoutLength))),
                        (6, quantity, (option, encoding: (u64, HighZeroBytesDroppedBigSize))),
                        (8, payer_note_truncated, (option, encoding: (String, WithoutLength))),
@@ -1171,7 +1162,7 @@ impl Readable for InvoiceRequestFields {
                let features = features.unwrap_or(InvoiceRequestFeatures::empty());
 
                Ok(InvoiceRequestFields {
-                       payer_id: payer_id.0.unwrap(), amount_msats, features, quantity,
+                       payer_id: payer_id.0.unwrap(), features, quantity,
                        payer_note_truncated: payer_note_truncated.map(|s| UntrustedString(s)),
                })
        }
@@ -2277,7 +2268,6 @@ mod tests {
                                        fields,
                                        InvoiceRequestFields {
                                                payer_id: payer_pubkey(),
-                                               amount_msats: Some(1001),
                                                features: InvoiceRequestFeatures::empty(),
                                                quantity: Some(1),
                                                payer_note_truncated: Some(UntrustedString("0".repeat(PAYER_NOTE_LIMIT))),