merchant

commit b0c73f8d7c39b6c342b497030b31ec6dc089e9c5
parent c50f08ddd051b165012c9b331eb34acc5c03a828
Author: Christian Grothoff <grothoff@gnunet.org>
Date:   Mon, 20 Jul 2026 09:19:39 +0200

keep data_source alive while MHD needs it

Diffstat:
M
src/backend/taler-merchant-httpd.c
 | 
1
+
M
src/backend/taler-merchant-httpd.h
 | 
11
+++++++++++
M
src/backend/taler-merchant-httpd_dispatcher.c
 | 
4
++++
M
src/backend/taler-merchant-httpd_post-reports-REPORT_ID.c
 | 
11
+++++++++--

4 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/src/backend/taler-merchant-httpd.c b/src/backend/taler-merchant-httpd.c
@@ -329,6 +329,7 @@ handle_mhd_completion_callback (void *cls,
     hc->cc (hc->ctx);
   TALER_MHD_parse_post_cleanup_callback (hc->json_parse_context);
   GNUNET_free (hc->infix);
+  GNUNET_free (hc->rewritten_url);
   if (NULL != hc->request_body)
     json_decref (hc->request_body);
   if (NULL != hc->instance)
diff --git a/src/backend/taler-merchant-httpd.h b/src/backend/taler-merchant-httpd.h
@@ -615,6 +615,17 @@ struct TMH_HandlerContext
   char *infix;
 
   /**
+   * URL a request was internally rewritten to (e.g. by the
+   * POST /reports/$REPORT_ID handler that re-dispatches to the
+   * report's data source).  When a request is rewritten, query
+   * arguments are registered on the connection with pointers
+   * *into* this buffer via MHD_set_connection_value(), which does
+   * not copy them; the buffer must therefore stay alive until the
+   * connection is finished.  Freed in the completion callback.
+   */
+  char *rewritten_url;
+
+  /**
    * Which connection was suspended.
    */
   struct MHD_Connection *connection;
diff --git a/src/backend/taler-merchant-httpd_dispatcher.c b/src/backend/taler-merchant-httpd_dispatcher.c
@@ -1475,6 +1475,10 @@ identify_handler (struct TMH_HandlerContext *hc,
         suffix_url = slash + 1;   /* skip the '/' */
         suffix_strlen = strlen (suffix_url);
       }
+      /* free any previously set infix in case the request is being
+         re-dispatched (e.g. via POST /reports/$REPORT_ID), otherwise
+         the earlier infix would be leaked */
+      GNUNET_free (hc->infix);
       hc->infix = GNUNET_strndup (infix_url,
                                   infix_strlen);
     }
diff --git a/src/backend/taler-merchant-httpd_post-reports-REPORT_ID.c b/src/backend/taler-merchant-httpd_post-reports-REPORT_ID.c
@@ -174,6 +174,15 @@ TMH_post_reports_ID (
     }
 
     hc->rh = NULL; /* just to make it clear: current one will NOT remain */
+    /* The query arguments parsed above were registered on the
+       connection with pointers *into* @e data_source (MHD does not
+       copy them).  Ownership of @e data_source is therefore handed to
+       @e hc, which frees it only once the connection is finished; we
+       must NOT free it here (doing so would leave the connection --
+       and the re-dispatched GET handler that reads those arguments --
+       with dangling pointers). */
+    GNUNET_free (hc->rewritten_url);
+    hc->rewritten_url = data_source;
     ret = TMH_dispatch_request (hc,
                                 data_source,
                                 MHD_HTTP_METHOD_GET,
@@ -183,13 +192,11 @@ TMH_post_reports_ID (
     if (GNUNET_OK != ret)
     {
       GNUNET_free (instance_id);
-      GNUNET_free (data_source);
       return (GNUNET_NO == ret) ? MHD_YES : MHD_NO;
     }
     GNUNET_break (NULL != hc->rh);
   }
   GNUNET_free (instance_id);
-  GNUNET_free (data_source);
   /* MHD will call the main handler again, which will now
      dispatch into the _new_ handler callback we just installed! */
   return MHD_YES;