work-around engine dialog crashes.

Thanks to brilliant detective work by John E. we
can now reveal that the actual crash in
EngineControl::print_channel_count() is caused
by a seemingly unrelated exception.

The root cause however is waves/ASIO backend reporting a
buffersize that is not in list of available buffer-sizes
it reported earlier.

diff --git a/gtk2_ardour/engine_dialog.cc b/gtk2_ardour/engine_dialog.cc
index dfa22e60354278338eaad9f241d94e3269d6db38..742dce03f88272f6fff84b7aec06caaceb611d74 100644 (file)
--- a/gtk2_ardour/engine_dialog.cc
+++ b/gtk2_ardour/engine_dialog.cc
@@ -1013,7 +1013,7 @@ EngineControl::device_changed ()
                        if (0 == period) {
                                period = backend->default_buffer_size(device_name);
                        }
-                       buffer_size_combo.set_active_text (bufsize_as_string (period));
+                       set_active_text_if_present (buffer_size_combo, bufsize_as_string (period));
                        show_buffer_duration ();
                } else {
                        buffer_size_combo.set_sensitive (false);
@@ -1247,7 +1247,7 @@ EngineControl::maybe_display_saved_state ()
                if (!_desired_sample_rate) {
                        sample_rate_combo.set_active_text (rate_as_string (state->sample_rate));
                }
-               buffer_size_combo.set_active_text (bufsize_as_string (state->buffer_size));
+               set_active_text_if_present (buffer_size_combo, bufsize_as_string (state->buffer_size));
                /* call this explicitly because we're ignoring changes to
                   the controls at this point.
                 */
@@ -1465,7 +1465,7 @@ EngineControl::set_state (const XMLNode& root)
                        driver_combo.set_active_text ((*i)->driver);
                        device_combo.set_active_text ((*i)->device);
                        sample_rate_combo.set_active_text (rate_as_string ((*i)->sample_rate));
-                       buffer_size_combo.set_active_text (bufsize_as_string ((*i)->buffer_size));
+                       set_active_text_if_present (buffer_size_combo, bufsize_as_string ((*i)->buffer_size));
                        input_latency.set_value ((*i)->input_latency);
                        output_latency.set_value ((*i)->output_latency);
                        midi_option_combo.set_active_text ((*i)->midi_option);
@@ -1784,6 +1784,8 @@ EngineControl::get_buffer_size () const
        uint32_t samples;
 
        if (sscanf (txt.c_str(), "%d", &samples) != 1) {
+               fprintf(stderr, "Find a trout and repeatedly slap the nearest C++ who throws exceptions without catching them.\n");
+               fprintf(stderr, "Ardour will likely crash now, giving you time to get the trout.\n");
                throw exception ();
        }
 
@@ -2175,7 +2177,7 @@ EngineControl::engine_running ()
        boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
        assert (backend);
 
-       buffer_size_combo.set_active_text (bufsize_as_string (backend->buffer_size()));
+       set_active_text_if_present (buffer_size_combo, bufsize_as_string (backend->buffer_size()));
        sample_rate_combo.set_active_text (rate_as_string (backend->sample_rate()));
 
        buffer_size_combo.set_sensitive (true);