diff --git a/src/include/taler_error_codes.h b/src/include/taler_error_codes.h
index 1e031f4b6..87feea2d3 100644
--- a/src/include/taler_error_codes.h
+++ b/src/include/taler_error_codes.h
@@ -2165,6 +2165,61 @@ enum TALER_ErrorCode
    */
   TALER_EC_RESERVES_DELETE_NO_SUCH_RESERVE = 2722,
 
+  /**
+   * The backend got an unexpected error trying to lookup reserve
+   * details from the backend. This response is provided with HTTP
+   * status code #MHD_HTTP_INTERNAL_SERVER_ERROR.
+   */
+  TALER_EC_TIP_LOOKUP_RESERVE_DB_FAILURE = 2723,
+
+  /**
+   * The backend repeatedly failed to serialize the transaction to
+   * authorize the tip. This response is provided with HTTP status code
+   * #MHD_HTTP_INTERNAL_SERVER_ERROR.
+   */
+  TALER_EC_TIP_AUTHORIZE_DB_SERIALIZATION_FAILURE = 2724,
+
+  /**
+   * The backend failed to start the transaction to authorize the tip.
+   * This response is provided with HTTP status code
+   * #MHD_HTTP_INTERNAL_SERVER_ERROR.
+   */
+  TALER_EC_TIP_AUTHORIZE_DB_START_FAILURE = 2725,
+
+  /**
+   * The backend failed looking up the reserve needed to authorize the
+   * tip. This response is provided with HTTP status code
+   * #MHD_HTTP_INTERNAL_SERVER_ERROR.
+   */
+  TALER_EC_TIP_AUTHORIZE_DB_LOOKUP_RESERVE_FAILURE = 2726,
+
+  /**
+   * The backend failed to find a reserve needed to authorize the tip.
+   * This response is provided with HTTP status code
+   * #MHD_HTTP_SERVICE_UNAVAILABLE.
+   */
+  TALER_EC_TIP_AUTHORIZE_DB_RESERVE_NOT_FOUND = 2727,
+
+  /**
+   * The backend encountered an internal invariant violation. This
+   * response is provided with HTTP status code
+   * #MHD_HTTP_INTERNAL_SERVER_ERROR.
+   */
+  TALER_EC_TIP_AUTHORIZE_DB_RESERVE_INVARIANT_FAILURE = 2728,
+
+  /**
+   * The selected exchange expired. This response is provided with HTTP
+   * status code #MHD_HTTP_GONE.
+   */
+  TALER_EC_TIP_AUTHORIZE_DB_RESERVE_EXPIRED = 2729,
+
+  /**
+   * The backend failed updating the reserve needed to authorize the
+   * tip. This response is provided with HTTP status code
+   * #MHD_HTTP_INTERNAL_SERVER_ERROR.
+   */
+  TALER_EC_TIP_AUTHORIZE_DB_UPDATE_RESERVE_FAILURE = 2730,
+
   /**
    * The backend had trouble accessing the database to persist
    * information about enabling tips. Returned with an HTTP status code
diff --git a/src/lib/exchange_api_melt.c b/src/lib/exchange_api_melt.c
index f89036e40..0695f997b 100644
--- a/src/lib/exchange_api_melt.c
+++ b/src/lib/exchange_api_melt.c
@@ -445,11 +445,11 @@ TALER_EXCHANGE_melt (struct TALER_EXCHANGE_Handle *exchange,
     char pub_str[sizeof (struct TALER_CoinSpendPublicKeyP) * 2];
     char *end;
 
-    end = GNUNET_STRINGS_data_to_string (&melt.coin_pub,
-                                         sizeof (struct
-                                                 TALER_CoinSpendPublicKeyP),
-                                         pub_str,
-                                         sizeof (pub_str));
+    end = GNUNET_STRINGS_data_to_string (
+      &melt.coin_pub,
+      sizeof (struct TALER_CoinSpendPublicKeyP),
+      pub_str,
+      sizeof (pub_str));
     *end = '\0';
     GNUNET_snprintf (arg_str,
                      sizeof (arg_str),