make tipping work with latest merchant protocol

packages/taler-util/src/talerTypes.ts

@@ -1654,3 +1654,14 @@ export enum ExchangeProtocolVersion {
   V9 = 9,
   V12 = 12,
 }
+
+export enum MerchantProtocolVersion {
+  /**
+   * Legacy version that is still supported.
+   */
+  V1 = 1,
+  /**
+   * Current version supported by the wallet.
+   */
+  V3 = 3,
+}

packages/taler-wallet-core/src/operations/tip.ts

@@ -33,6 +33,7 @@ import {
   DenomKeyType,
   BlindedDenominationSignature,
   codecForMerchantTipResponseV2,
+  MerchantProtocolVersion,
 } from "@gnu-taler/taler-util";
 import { DerivedTipPlanchet } from "../crypto/cryptoTypes.js";
 import {
@@ -314,13 +315,15 @@ async function processTipImpl(
 
   let blindedSigs: BlindedDenominationSignature[] = [];
 
-  if (merchantInfo.protocolVersionCurrent === 2) {
+  if (merchantInfo.protocolVersionCurrent === MerchantProtocolVersion.V3) {
     const response = await readSuccessResponseJsonOrThrow(
       merchantResp,
       codecForMerchantTipResponseV2(),
     );
     blindedSigs = response.blind_sigs.map((x) => x.blind_sig);
-  } else if (merchantInfo.protocolVersionCurrent === 1) {
+  } else if (
+    merchantInfo.protocolVersionCurrent === MerchantProtocolVersion.V1
+  ) {
     const response = await readSuccessResponseJsonOrThrow(
       merchantResp,
       codecForMerchantTipResponseV1(),
@@ -330,7 +333,9 @@ async function processTipImpl(
       blinded_rsa_signature: x.blind_sig,
     }));
   } else {
-    throw Error("unsupported merchant protocol version");
+    throw Error(
+      `unsupported merchant protocol version (${merchantInfo.protocolVersionCurrent})`,
+    );
   }
 
   if (blindedSigs.length !== planchets.length) {