merchant

commit 376dc1548dbc1cfde90c100bd55abf1de84973a8
parent 1a5f1cbdb517dc3b570f28fdedf2f136fbb0f2a8
Author: Christian Grothoff <christian@grothoff.org>
Date:   Wed, 27 May 2026 17:25:56 +0200

allow exchange selection to fail if the payment amount is zero

Diffstat:
M
src/backend/taler-merchant-httpd_post-private-orders.c
 | 
24
+++++++++++++++++++++++-

1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/src/backend/taler-merchant-httpd_post-private-orders.c b/src/backend/taler-merchant-httpd_post-private-orders.c
@@ -2322,6 +2322,26 @@ phase_select_wire_method (struct OrderContext *oc)
   struct WireMethodCandidate *best = NULL;
   unsigned int max_choices = 0;
   unsigned int want_choices = 0;
+  bool zero_amount = false;
+
+  switch (oc->parse_order.order->base->version)
+  {
+  case TALER_MERCHANT_CONTRACT_VERSION_0:
+    ea = &oc->parse_order.order->details.v0.brutto;
+    if (TALER_amount_is_zero (ea))
+      zero_amount = true;
+    break;
+  case TALER_MERCHANT_CONTRACT_VERSION_1:
+    for (unsigned int i = 0; i<oc->parse_choices.choices_len; i++)
+    {
+      ea = &oc->parse_choices.choices[i].amount;
+      if (TALER_amount_is_zero (ea))
+        zero_amount = true;
+    }
+    break;
+  default:
+    GNUNET_assert (0);
+  }
 
   for (struct WireMethodCandidate *wmc = oc->add_payment_details.wmc_head;
        NULL != wmc;
@@ -2379,6 +2399,7 @@ phase_select_wire_method (struct OrderContext *oc)
   }
 
   if ( (NULL == best) &&
+       (! zero_amount) &&
        (NULL != oc->parse_request.payment_target) )
   {
     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
@@ -2392,7 +2413,8 @@ phase_select_wire_method (struct OrderContext *oc)
     return;
   }
 
-  if (NULL == best)
+  if ( (NULL == best) &&
+       (! zero_amount) )
   {
     enum MHD_Result mret;