fix redirection issue to preserve query parameters

2 files changed, 36 insertions, 8 deletions

diff --git a/src/backend/taler-merchant-httpd.c b/src/backend/taler-merchant-httpd.c
index 42cf08ee..829daf55 100644
--- a/src/backend/taler-merchant-httpd.c
+++ b/src/backend/taler-merchant-httpd.c
@@ -1,6 +1,6 @@
 /*
   This file is part of TALER
-  (C) 2014-2022 Taler Systems SA
+  (C) 2014-2024 Taler Systems SA
 
   TALER is free software; you can redistribute it and/or modify it under the
   terms of the GNU Affero General Public License as published by the Free Software
@@ -497,6 +497,7 @@ handle_mhd_completion_callback (void *cls,
     json_decref (hc->request_body);
   if (NULL != hc->instance)
     TMH_instance_decref (hc->instance);
+  GNUNET_free (hc->full_url);
   GNUNET_free (hc);
   *con_cls = NULL;
 }
@@ -736,6 +737,29 @@ prefix_match (const struct TMH_RequestHandler *rh,
 
 
 /**
+ * Function called first by MHD with the full URL.
+ *
+ * @param cls NULL
+ * @param full_url the full URL
+ * @param con MHD connection object
+ * @return our handler context
+ */
+static void *
+full_url_track_callback (void *cls,
+                         const char *full_url,
+                         struct MHD_Connection *con)
+{
+  struct TMH_HandlerContext *hc;
+
+  hc = GNUNET_new (struct TMH_HandlerContext);
+  GNUNET_async_scope_fresh (&hc->async_scope_id);
+  GNUNET_SCHEDULER_begin_async_scope (&hc->async_scope_id);
+  hc->full_url = GNUNET_strdup (full_url);
+  return hc;
+}
+
+
+/**
  * A client has requested the given url using the given method
  * (#MHD_HTTP_METHOD_GET, #MHD_HTTP_METHOD_PUT,
  * #MHD_HTTP_METHOD_DELETE, #MHD_HTTP_METHOD_POST, etc).  The callback
@@ -770,7 +794,8 @@ prefix_match (const struct TMH_RequestHandler *rh,
  *        If necessary, this state can be cleaned up in the
  *        global #MHD_RequestCompletedCallback (which
  *        can be set with the #MHD_OPTION_NOTIFY_COMPLETED).
- *        Initially, `*con_cls` will be NULL.
+ *        Initially, `*con_cls` will be set up by the
+ *        full_url_track_callback().
  * @return #MHD_YES if the connection was handled successfully,
  *         #MHD_NO if the socket must be closed due to a serious
  *         error while handling the request
@@ -1413,7 +1438,7 @@ url_handler (void *cls,
 
   (void) cls;
   (void) version;
-  if (NULL != hc)
+  if (NULL != hc->url)
   {
     /* MHD calls us again for a request, for first call
        see 'else' case below */
@@ -1461,10 +1486,6 @@ url_handler (void *cls,
                             connection,
                             hc);
   }
-  hc = GNUNET_new (struct TMH_HandlerContext);
-  *con_cls = hc;
-  GNUNET_async_scope_fresh (&hc->async_scope_id);
-  GNUNET_SCHEDULER_begin_async_scope (&hc->async_scope_id);
   hc->url = url;
   {
     const char *correlation_id;
@@ -1509,7 +1530,7 @@ url_handler (void *cls,
                       strlen (instance_prefix)))
     {
       /* url starts with "/instances/" */
-      const char *istart = url + strlen (instance_prefix);
+      const char *istart = hc->full_url + strlen (instance_prefix);
       const char *slash = strchr (istart, '/');
       char *instance_id;
 
@@ -2303,6 +2324,8 @@ run (void *cls,
                             NULL, NULL,
                             &url_handler, NULL,
                             MHD_OPTION_LISTEN_SOCKET, fh,
+                            MHD_OPTION_URI_LOG_CALLBACK,
+                            &full_url_track_callback, NULL,
                             MHD_OPTION_NOTIFY_COMPLETED,
                             &handle_mhd_completion_callback, NULL,
                             MHD_OPTION_CONNECTION_TIMEOUT,
diff --git a/src/backend/taler-merchant-httpd.h b/src/backend/taler-merchant-httpd.h
index 7ccf0575..1e5e955d 100644
--- a/src/backend/taler-merchant-httpd.h
+++ b/src/backend/taler-merchant-httpd.h
@@ -589,6 +589,11 @@ struct TMH_HandlerContext
   const char *url;
 
   /**
+   * Copy of our original full URL with query parameters.
+   */
+  char *full_url;
+
+  /**
    * Client-provided authentication token for this
    * request, can be NULL.
    *