handle zero-amount orders better

3 files changed, 24 insertions, 4 deletions

diff --git a/src/backend/taler-merchant-httpd_post-orders-ID-pay.c b/src/backend/taler-merchant-httpd_post-orders-ID-pay.c
index 349b4d24..555e2959 100644
--- a/src/backend/taler-merchant-httpd_post-orders-ID-pay.c
+++ b/src/backend/taler-merchant-httpd_post-orders-ID-pay.c
@@ -1240,7 +1240,6 @@ process_pay_with_keys (
     return;
   }
 
-  /* FIXME: actually enforce max_amount below! */
   max_amount = eg->total;
   if (GNUNET_OK !=
       TMH_exchange_check_debit (
@@ -1261,6 +1260,18 @@ process_pay_with_keys (
     force_keys (eg);
     return;
   }
+  if (-1 ==
+      TALER_amount_cmp (&max_amount,
+                        &eg->total))
+  {
+    /* max_amount < eg->total */
+    GNUNET_break_op (0);
+    resume_pay_with_error (
+      pc,
+      TALER_EC_MERCHANT_POST_ORDERS_ID_PAY_EXCHANGE_TRANSACTION_LIMIT_VIOLATION,
+      eg->exchange_url);
+    return;
+  }
 
   if (GNUNET_OK !=
       TMH_EXCHANGES_lookup_wire_fee (exchange,
diff --git a/src/backend/taler-merchant-httpd_private-post-orders.c b/src/backend/taler-merchant-httpd_private-post-orders.c
index 9215bc6f..075c2bbe 100644
--- a/src/backend/taler-merchant-httpd_private-post-orders.c
+++ b/src/backend/taler-merchant-httpd_private-post-orders.c
@@ -1929,7 +1929,8 @@ get_acceptable (void *cls,
               "Exchange %s evaluated at %d\n",
               url,
               res);
-  if (TALER_amount_is_zero (&max_amount))
+  if ( (! TALER_amount_is_zero (&max_amount)) &&
+       (TALER_amount_is_zero (&max_amount)) )
   {
     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                 "Exchange %s deposit limit is zero, skipping it\n",
@@ -2071,6 +2072,14 @@ get_exchange_keys (void *cls,
 static bool
 set_exchanges (struct OrderContext *oc)
 {
+  if (TALER_amount_is_zero (&oc->parse_order.brutto))
+  {
+    /* Total amount is zero, so we don't actually need exchanges! */
+    oc->set_exchanges.exchanges = json_array ();
+    GNUNET_assert (NULL != oc->set_exchanges.exchanges);
+    oc->phase++;
+    return false;
+  }
   /* Note: re-building 'oc->set_exchanges.exchanges' every time here might be a
      tad expensive; could likely consider caching the result if it starts to
      matter. */
diff --git a/src/lib/test_merchant_api_common.c b/src/lib/test_merchant_api_common.c
index 821e04a8..e0eb49fa 100644
--- a/src/lib/test_merchant_api_common.c
+++ b/src/lib/test_merchant_api_common.c
@@ -27,11 +27,11 @@ int
 main (int argc,
       const char *const argv[])
 {
-  (void) argc;
-  (void) argv;
   struct TALER_MERCHANT_PayUriData pd;
   struct TALER_MERCHANT_RefundUriData rd;
 
+  (void) argc;
+  (void) argv;
   GNUNET_log_setup ("test_merchant_api_common",
                     "WARNING",
                     NULL);