Don't call AudioBackend::enumerate_drivers for Backend states without driver selection

AudioBackend::enumerate_drivers is not supposed to be called for backends that
don't support driver selection. The wavesaudio backend asserts if the method is
called.

diff --git a/gtk2_ardour/engine_dialog.cc b/gtk2_ardour/engine_dialog.cc
index 695940e44687e51fcc24a1f7d67b53364c715af5..bdf00207e6ddcfa484cc2d79d1d525e2c985b301 100644 (file)
--- a/gtk2_ardour/engine_dialog.cc
+++ b/gtk2_ardour/engine_dialog.cc
@@ -1775,7 +1775,9 @@ EngineControl::set_state (const XMLNode& root)
                         * can also be set to valid entries and the state will be restored
                         * correctly.
                         */
-                       set_driver_popdown_strings ();
+                       if (!(*i)->driver.empty()) {
+                               set_driver_popdown_strings ();
+                       }
                        driver_combo.set_active_text ((*i)->driver);
                        backend_changed ();