anastasis

commit 88c04f61150c2334015439b27bfd5c8a52849ef9
parent f93e54134818d14c87d5a3cbf97d1c0874155a16
Author: Christian Grothoff <christian@grothoff.org>
Date:   Tue,  4 Aug 2026 15:34:14 +0200

fix issue where race might create concurrent payment requests for the same challenge

Diffstat:
M
src/stasis/get_pending_challenge_payment.c
 | 
9
++++++++-

1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/src/stasis/get_pending_challenge_payment.c b/src/stasis/get_pending_challenge_payment.c
@@ -67,7 +67,14 @@ ANASTASIS_DB_get_pending_challenge_payment (
            " AND"
            "  truth_uuid=$1"
            " AND"
-           "  creation_date > $2;");
+           "  creation_date > $2"
+           /* Nothing stops a truth from having more than one pending offer:
+              the callers check for one and then insert after a round trip to
+              the merchant, so two concurrent challenge requests race and both
+              insert.  Without this the singleton select would then report a
+              hard error.  Point the client at the most recent offer. */
+           " ORDER BY creation_date DESC"
+           " LIMIT 1;");
   return GNUNET_PQ_eval_prepared_singleton_select (pg->conn,
                                                    "get_pending_challenge_payment",
                                                    params,