merchant

commit 361f28341a7585acf6c4eb5c7e9db8b116993ae1
parent b5260e975b225731b50787c2aca986a5898b8f14
Author: Christian Grothoff <christian@grothoff.org>
Date:   Sun,  2 Aug 2026 20:46:04 +0200

fix GET /private/orders/ long-polling

Diffstat:
M
src/backend/taler-merchant-httpd_get-private-orders-ORDER_ID.c
 | 
85
+++++++++++++++++++++++++++++++++++++++++++++++++++++++------------------------

1 file changed, 59 insertions(+), 26 deletions(-)
diff --git a/src/backend/taler-merchant-httpd_get-private-orders-ORDER_ID.c b/src/backend/taler-merchant-httpd_get-private-orders-ORDER_ID.c
@@ -430,6 +430,18 @@ struct GetOrderRequestContext
   bool paid_session_matches;
 
   /**
+   * When we install the @e session_eh listener, we already checked
+   * the order status. We could not do it earlier, because the
+   * fulfillment URL was unavailable. However, this leaves a chance
+   * for a payment event to be missed if it happens before the first
+   * order status check and us installing the event listener. Thus,
+   * if we afterwards suspend, we should once *immediately* check the
+   * order status a 2nd time before we really suspend. This flag is
+   * set to true to handle this case.
+   */
+  bool instant_retry;
+
+  /**
    * True if the exchange wired the money to the merchant.
    */
   bool wired;
@@ -641,32 +653,6 @@ phase_init (struct GetOrderRequestContext *gorc)
     GNUNET_TIME_absolute_get_remaining (gorc->sc.long_poll_timeout),
     &resume_by_event,
     gorc);
-  if ( (NULL != gorc->session_id) &&
-       (NULL != gorc->ct->fulfillment_url) )
-  {
-    struct TMH_SessionEventP session_eh = {
-      .header.size = htons (sizeof (session_eh)),
-      .header.type = htons (TALER_DBEVENT_MERCHANT_SESSION_CAPTURED),
-      .merchant_pub = hc->instance->merchant_pub
-    };
-
-    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-                "Subscribing to session triggers for %p\n",
-                gorc);
-    GNUNET_CRYPTO_hash (gorc->session_id,
-                        strlen (gorc->session_id),
-                        &session_eh.h_session_id);
-    GNUNET_CRYPTO_hash (gorc->ct->fulfillment_url,
-                        strlen (gorc->ct->fulfillment_url),
-                        &session_eh.h_fulfillment_url);
-    gorc->session_eh
-      = TALER_MERCHANTDB_event_listen (
-          TMH_db,
-          &session_eh.header,
-          GNUNET_TIME_absolute_get_remaining (gorc->sc.long_poll_timeout),
-          &resume_by_event,
-          gorc);
-  }
   gorc->phase++;
 }
 
@@ -856,6 +842,40 @@ phase_parse_contract (struct GetOrderRequestContext *gorc)
     }
   }
 
+  /* Now that the contract terms (and thus the fulfillment URL) are
+     available, subscribe to session-capture triggers if requested.
+     The @e session_eh guard makes this idempotent across the phase
+     re-runs of the long-polling loop; @e gorc->session_eh is cancelled
+     in gorc_cleanup(). */
+  if ( (NULL != gorc->session_id) &&
+       (NULL != gorc->ct->fulfillment_url) &&
+       (NULL == gorc->session_eh) )
+  {
+    struct TMH_SessionEventP session_eh = {
+      .header.size = htons (sizeof (session_eh)),
+      .header.type = htons (TALER_DBEVENT_MERCHANT_SESSION_CAPTURED),
+      .merchant_pub = hc->instance->merchant_pub
+    };
+
+    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+                "Subscribing to session triggers for %p\n",
+                gorc);
+    GNUNET_CRYPTO_hash (gorc->session_id,
+                        strlen (gorc->session_id),
+                        &session_eh.h_session_id);
+    GNUNET_CRYPTO_hash (gorc->ct->fulfillment_url,
+                        strlen (gorc->ct->fulfillment_url),
+                        &session_eh.h_fulfillment_url);
+    gorc->session_eh
+      = TALER_MERCHANTDB_event_listen (
+          TMH_db,
+          &session_eh.header,
+          GNUNET_TIME_absolute_get_remaining (gorc->sc.long_poll_timeout),
+          &resume_by_event,
+          gorc);
+    gorc->instant_retry = true;
+  }
+
   switch (gorc->ct->version)
   {
   case TALER_MERCHANT_CONTRACT_VERSION_0:
@@ -1008,6 +1028,13 @@ check_reply (struct GetOrderRequestContext *gorc,
     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                 "Status unchanged, not returning response yet\n");
     GNUNET_assert (GNUNET_NO == gorc->suspended);
+    if (gorc->instant_retry)
+    {
+      gorc->instant_retry = false;
+      gorc->phase = GOP_FETCH_CONTRACT;
+      GNUNET_free (can);
+      return;
+    }
     /* note: not necessarily actually unpaid ... */
     GNUNET_CONTAINER_DLL_insert (gorc_head,
                                  gorc_tail,
@@ -1211,6 +1238,12 @@ phase_unpaid_finish (struct GetOrderRequestContext *gorc)
   if (GNUNET_TIME_absolute_is_future (gorc->sc.long_poll_timeout) &&
       (! gorc->have_lp_not_etag) )
   {
+    if (gorc->instant_retry)
+    {
+      gorc->instant_retry = false;
+      gorc->phase = GOP_FETCH_CONTRACT;
+      return;
+    }
     GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                 "Suspending GET /private/orders/%s\n",
                 hc->infix);