lnrpc: remove receipt field from invoice

lnrpc/invoicesrpc/addinvoice.go

@@ -57,10 +57,6 @@ type AddInvoiceData struct {
 	// description_hash field is not being used.
 	Memo string
 
-	// Deprecated. An optional cryptographic receipt of payment which is not
-	// implemented.
-	Receipt []byte
-
 	// The preimage which will allow settling an incoming HTLC payable to
 	// this preimage. If Preimage is set, Hash should be nil. If both
 	// Preimage and Hash are nil, a random preimage is generated.
@@ -154,10 +150,6 @@ func AddInvoice(ctx context.Context, cfg *AddInvoiceConfig,
 		return nil, nil, fmt.Errorf("memo too large: %v bytes "+
 			"(maxsize=%v)", len(invoice.Memo), channeldb.MaxMemoSize)
 	}
-	if len(invoice.Receipt) > channeldb.MaxReceiptSize {
-		return nil, nil, fmt.Errorf("receipt too large: %v bytes "+
-			"(maxsize=%v)", len(invoice.Receipt), channeldb.MaxReceiptSize)
-	}
 	if len(invoice.DescriptionHash) > 0 && len(invoice.DescriptionHash) != 32 {
 		return nil, nil, fmt.Errorf("description hash is %v bytes, must be 32",
 			len(invoice.DescriptionHash))
@@ -392,7 +384,6 @@ func AddInvoice(ctx context.Context, cfg *AddInvoiceConfig,
 	newInvoice := &channeldb.Invoice{
 		CreationDate:   creationDate,
 		Memo:           []byte(invoice.Memo),
-		Receipt:        invoice.Receipt,
 		PaymentRequest: []byte(payReqString),
 		FinalCltvDelta: int32(payReq.MinFinalCLTVExpiry()),
 		Expiry:         payReq.Expiry(),

lnrpc/invoicesrpc/utils.go

@@ -94,7 +94,6 @@ func CreateRPCInvoice(invoice *channeldb.Invoice,
 
 	rpcInvoice := &lnrpc.Invoice{
 		Memo:            string(invoice.Memo[:]),
-		Receipt:         invoice.Receipt[:],
 		RHash:           decoded.PaymentHash[:],
 		Value:           int64(satAmt),
 		ValueMsat:       int64(invoice.Terms.Value),

lnrpc/rpc.proto

@@ -2217,10 +2217,7 @@ message Invoice {
     */
     string memo = 1 [json_name = "memo"];
 
-    /** Deprecated. An optional cryptographic receipt of payment which is not
-    implemented.
-    */
-    bytes receipt = 2 [json_name = "receipt", deprecated = true];
+    reserved 2;
 
     /**
     The hex-encoded preimage (32 byte) which will allow settling an incoming

lnrpc/rpc.swagger.json

@@ -2660,11 +2660,6 @@
           "type": "string",
           "description": "*\nAn optional memo to attach along with the invoice. Used for record keeping\npurposes for the invoice's creator, and will also be set in the description\nfield of the encoded payment request if the description_hash field is not\nbeing used."
         },
-        "receipt": {
-          "type": "string",
-          "format": "byte",
-          "description": "* Deprecated. An optional cryptographic receipt of payment which is not\nimplemented."
-        },
         "r_preimage": {
           "type": "string",
           "format": "byte",