From f23e2c2cdc8d2665d76a335f58a640763c9a425e Mon Sep 17 00:00:00 2001
From: Christian Grothoff <christian@grothoff.org>
Date: Mon, 24 Aug 2020 14:12:02 +0200
Subject: make fulfillment URL optional, fix #6498 as discussed

---
 src/backenddb/plugin_merchantdb_postgres.c | 41 ++++++++++++++++++++++++++----
 1 file changed, 36 insertions(+), 5 deletions(-)

(limited to 'src/backenddb')

diff --git a/src/backenddb/plugin_merchantdb_postgres.c b/src/backenddb/plugin_merchantdb_postgres.c
index 83a4cea2..37d1992f 100644
--- a/src/backenddb/plugin_merchantdb_postgres.c
+++ b/src/backenddb/plugin_merchantdb_postgres.c
@@ -1482,6 +1482,31 @@ postgres_lookup_contract_terms (void *cls,
 }
 
 
+/**
+ * Create a dummy URL for the 'fulfillment' URL that consist
+ * of random letters. Used because we do not like putting NULL
+ * into the database, but do need to ensure that a query
+ * never matches this URL.
+ *
+ * @return randomized URL starting with "void://", changes at
+ *         ever call to this function
+ */
+static const char *
+make_dummy_url (void)
+{
+  static char buf[128] = "void://";
+  struct GNUNET_HashCode hc;
+
+  GNUNET_CRYPTO_hash_create_random (GNUNET_CRYPTO_QUALITY_NONCE,
+                                    &hc);
+  GNUNET_STRINGS_data_to_string (&hc,
+                                 sizeof (hc),
+                                 &buf[7],
+                                 sizeof (buf) - 8);
+  return buf;
+}
+
+
 /**
  * Store contract terms given its @a order_id. Note that some attributes are
  * expected to be calculated inside of the function, like the hash of the
@@ -1519,8 +1544,6 @@ postgres_insert_contract_terms (void *cls,
 
   {
     struct GNUNET_JSON_Specification spec[] = {
-      GNUNET_JSON_spec_string ("fulfillment_url",
-                               &fulfillment_url),
       TALER_JSON_spec_absolute_time ("pay_deadline",
                                      &pay_deadline),
       TALER_JSON_spec_absolute_time ("refund_deadline",
@@ -1539,6 +1562,11 @@ postgres_insert_contract_terms (void *cls,
     }
   }
 
+  fulfillment_url =
+    json_string_value (json_object_get (contract_terms,
+                                        "fulfillment_url"));
+  if (NULL == fulfillment_url)
+    fulfillment_url = make_dummy_url ();
   check_connection (pg);
   {
     struct GNUNET_PQ_QueryParam params[] = {
@@ -1596,8 +1624,6 @@ postgres_update_contract_terms (void *cls,
 
   {
     struct GNUNET_JSON_Specification spec[] = {
-      GNUNET_JSON_spec_string ("fulfillment_url",
-                               &fulfillment_url),
       TALER_JSON_spec_absolute_time ("pay_deadline",
                                      &pay_deadline),
       TALER_JSON_spec_absolute_time ("refund_deadline",
@@ -1616,6 +1642,12 @@ postgres_update_contract_terms (void *cls,
     }
   }
 
+  fulfillment_url =
+    json_string_value (json_object_get (contract_terms,
+                                        "fulfillment_url"));
+  if (NULL == fulfillment_url)
+    fulfillment_url = make_dummy_url ();
+
   check_connection (pg);
   {
     struct GNUNET_PQ_QueryParam params[] = {
@@ -3232,7 +3264,6 @@ postgres_lookup_order_by_fulfillment (void *cls,
                                       char **order_id)
 {
   struct PostgresClosure *pg = cls;
-
   struct GNUNET_PQ_QueryParam params[] = {
     GNUNET_PQ_query_param_string (instance_id),
     GNUNET_PQ_query_param_string (fulfillment_url),
-- 
cgit v1.2.3