test case of /payback done twice, handle 403-case in /payback handler, thereby also testing coin-with-payback history case in test logic (fixes #3887)

4 files changed, 42 insertions, 2 deletions

diff --git a/src/exchange-lib/exchange_api_payback.c b/src/exchange-lib/exchange_api_payback.c
index eff459693..30cd55cba 100644
--- a/src/exchange-lib/exchange_api_payback.c
+++ b/src/exchange-lib/exchange_api_payback.c
@@ -54,6 +54,11 @@ struct TALER_EXCHANGE_PaybackHandle
   char *json_enc;
 
   /**
+   * Denomination key of the coin.
+   */
+  const struct TALER_EXCHANGE_DenomPublicKey *pk;
+  
+  /**
    * Handle for the request.
    */
   struct GNUNET_CURL_Job *job;
@@ -181,6 +186,35 @@ handle_payback_finished (void *cls,
     /* This should never happen, either us or the exchange is buggy
        (or API version conflict); just pass JSON reply to the application */
     break;
+  case MHD_HTTP_FORBIDDEN:
+    {
+      /* Insufficient funds, proof attached */
+      json_t *history;
+      struct TALER_Amount total;
+      const struct TALER_EXCHANGE_DenomPublicKey *dki;
+
+      dki = ph->pk;
+      history = json_object_get (json,
+				 "history");
+      if (GNUNET_OK !=
+	  TALER_EXCHANGE_verify_coin_history (dki->fee_deposit.currency,
+					      &ph->coin_pub,
+					      history,
+					      &total))
+      {
+	GNUNET_break_op (0);
+	response_code = 0;
+      }
+      ph->cb (ph->cb_cls,
+	      response_code,
+	      TALER_JSON_get_error_code (json),
+	      &total,
+	      GNUNET_TIME_UNIT_FOREVER_ABS,
+	      NULL,
+	      json);
+      TALER_EXCHANGE_payback_cancel (ph);
+      return;
+    }
   case MHD_HTTP_UNAUTHORIZED:
     /* Nothing really to verify, exchange says one of the signatures is
        invalid; as we checked them, this should never happen, we
@@ -277,6 +311,7 @@ TALER_EXCHANGE_payback (struct TALER_EXCHANGE_Handle *exchange,
   ph = GNUNET_new (struct TALER_EXCHANGE_PaybackHandle);
   ph->coin_pub = pr.coin_pub;
   ph->exchange = exchange;
+  ph->pk = pk;
   ph->cb = payback_cb;
   ph->cb_cls = payback_cb_cls;
   ph->url = MAH_path_to_url (exchange, "/payback");
diff --git a/src/exchange-lib/test_exchange_api.c b/src/exchange-lib/test_exchange_api.c
index 5b64e79bd..fb0c93eb1 100644
--- a/src/exchange-lib/test_exchange_api.c
+++ b/src/exchange-lib/test_exchange_api.c
@@ -3501,6 +3501,11 @@ run (void *cls)
       .expected_response_code = MHD_HTTP_OK,
       .details.payback.ref = "payback-withdraw-coin-2a",
       .details.payback.amount = "EUR:0.5" },
+    { .oc = OC_PAYBACK,
+      .label = "payback-2b",
+      .expected_response_code = MHD_HTTP_FORBIDDEN,
+      .details.payback.ref = "payback-withdraw-coin-2a",
+      .details.payback.amount = "EUR:0.5" },
     { .oc = OC_DEPOSIT,
       .label = "payback-deposit-revoked",
       .expected_response_code = MHD_HTTP_NOT_FOUND,
diff --git a/src/exchange/taler-exchange-httpd_db.c b/src/exchange/taler-exchange-httpd_db.c
index 57be19708..d7f91c892 100644
--- a/src/exchange/taler-exchange-httpd_db.c
+++ b/src/exchange/taler-exchange-httpd_db.c
@@ -2396,7 +2396,6 @@ TEH_DB_execute_payback (struct MHD_Connection *connection,
   if ( (0 == amount.fraction) &&
        (0 == amount.value) )
   {
-    GNUNET_break_op (0);
     TEH_plugin->rollback (TEH_plugin->cls,
                           session);
     ret = TEH_RESPONSE_reply_coin_insufficient_funds (connection,
diff --git a/src/include/taler_exchange_service.h b/src/include/taler_exchange_service.h
index bd8e281d3..c097dff1a 100644
--- a/src/include/taler_exchange_service.h
+++ b/src/include/taler_exchange_service.h
@@ -1403,7 +1403,8 @@ struct TALER_EXCHANGE_PaybackHandle;
  * @param http_status HTTP response code, #MHD_HTTP_OK (200) for successful status request
  *                    0 if the exchange's reply is bogus (fails to follow the protocol)
  * @param ec taler-specific error code, #TALER_EC_NONE on success
- * @param amount amount the exchange will wire back for this coin
+ * @param amount amount the exchange will wire back for this coin,
+ *        on error the total balance remaining, or NULL
  * @param timestamp what time did the exchange receive the /payback request
  * @param reserve_pub public key of the reserve receiving the payback
  * @param full_response full response from the exchange (for logging, in case of errors)