do not attempt to save undo history if it is empty, and do not do any part of history...

diff --git a/libs/ardour/session_state.cc b/libs/ardour/session_state.cc
index 21088227d50f7010eb0b4be486207e002f7ddbd8..4e99c663f0521cb931f25826fb6888f792e3a345 100644 (file)
--- a/libs/ardour/session_state.cc
+++ b/libs/ardour/session_state.cc
@@ -3111,6 +3111,11 @@ Session::save_history (string snapshot_name)
                return 0;
        }
 
+       if (!Config->get_save_history() || Config->get_saved_history_depth() < 0 || 
+           (_history.undo_depth() == 0 && _history.redo_depth() == 0)) {
+               return 0;
+       }
+
        if (snapshot_name.empty()) {
                snapshot_name = _current_snapshot_name;
        }
@@ -3127,10 +3132,6 @@ Session::save_history (string snapshot_name)
                }
        }
 
-       if (!Config->get_save_history() || Config->get_saved_history_depth() < 0) {
-               return 0;
-       }
-
        tree.set_root (&_history.get_state (Config->get_saved_history_depth()));
 
        if (!tree.write (xml_path))