handle case where get_session() is called from main, i.e. in combination with -f option

src/exchange/test_taler_exchange_httpd_afl.sh

@@ -47,6 +47,6 @@ export GNUNET_FORCE_LOG=";;;;ERROR"
 for n in afl-tests/*
 do
   echo -n "Test $n "
-  $PREFIX taler-exchange-httpd -c test_taler_exchange_httpd.conf -t 1 -f $n -C > /dev/null && echo "OK" || echo "FAIL $!!"
+  $PREFIX taler-exchange-httpd -c test_taler_exchange_httpd.conf -t 1 -f $n -C > /dev/null && echo "OK" || echo "FAIL"
 done
 exit 0

src/exchangedb/plugin_exchangedb_postgres.c

@@ -134,6 +134,16 @@ struct PostgresClosure
    * Which currency should we assume all amounts to be in?
    */
   char *currency;
+
+  /**
+   * Session to be used if the thread is @e main_self.
+   */
+  struct TALER_EXCHANGEDB_Session *main_session;
+
+  /**
+   * Handle for the main() thread of the program.
+   */
+  pthread_t main_self;
 };
 
 
@@ -223,7 +233,12 @@ postgres_get_session (void *cls)
   struct GNUNET_PQ_Context *db_conn;
   struct TALER_EXCHANGEDB_Session *session;
 
-  if (NULL != (session = pthread_getspecific (pc->db_conn_threadlocal)))
+  if (pthread_equal (pc->main_self,
+                     pthread_self ()))
+    session = pc->main_session;
+  else
+    session = pthread_getspecific (pc->db_conn_threadlocal);
+  if (NULL != session)
   {
     GNUNET_PQ_reconnect_if_down (session->conn);
     return session;
@@ -1381,6 +1396,13 @@ postgres_get_session (void *cls)
     return NULL;
   session = GNUNET_new (struct TALER_EXCHANGEDB_Session);
   session->conn = db_conn;
+  if (pthread_equal (pc->main_self,
+                     pthread_self ()))
+  {
+    pc->main_session = session;
+  }
+  else
+  {
     if (0 != pthread_setspecific (pc->db_conn_threadlocal,
                                   session))
     {
@@ -1389,6 +1411,7 @@ postgres_get_session (void *cls)
       GNUNET_free (session);
       return NULL;
     }
+  }
   return session;
 }
 
@@ -7195,6 +7218,7 @@ libtaler_plugin_exchangedb_postgres_init (void *cls)
   const char *ec;
 
   pg = GNUNET_new (struct PostgresClosure);
+  pg->main_self = pthread_self (); /* loaded while single-threaded! */
   if (GNUNET_OK !=
       GNUNET_CONFIGURATION_get_value_filename (cfg,
                                                "exchangedb-postgres",
@@ -7379,6 +7403,10 @@ libtaler_plugin_exchangedb_postgres_done (void *cls)
   struct TALER_EXCHANGEDB_Plugin *plugin = cls;
   struct PostgresClosure *pg = plugin->cls;
 
+  /* If we launched a session for the main thread,
+     kill it here before we unload */
+  if (NULL != pg->main_session)
+    db_conn_destroy (pg->main_session);
   GNUNET_free (pg->connection_cfg_str);
   GNUNET_free (pg->sql_dir);
   GNUNET_free (pg->currency);