New test.
[ardour.git] / libs / ardour / session_state.cc
index bb2434b6c6ea0ebffe5dc650350ae239980b4752..7d6f44b7861d2566c1974b48c7e4cc76ca5ad7f0 100644 (file)
@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 1999-2002 Paul Davis 
+  Copyright (C) 1999-2002 Paul Davis
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-    
+
 */
 
-#define __STDC_FORMAT_MACROS 1
+
+#ifdef WAF_BUILD
+#include "libardour-config.h"
+#endif
+
 #include <stdint.h>
 
 #include <algorithm>
 #include <fstream>
 #include <string>
 #include <cerrno>
-
-#include <sigc++/bind.h>
-
 #include <cstdio> /* snprintf(3) ... grrr */
 #include <cmath>
 #include <unistd.h>
@@ -37,7 +38,6 @@
 #include <signal.h>
 #include <sys/mman.h>
 #include <sys/time.h>
-#include <dirent.h>
 
 #ifdef HAVE_SYS_VFS_H
 #include <sys/vfs.h>
 #include <sys/mount.h>
 #endif
 
+#include <glib.h>
+
 #include <glibmm.h>
 #include <glibmm/thread.h>
 
+#include <boost/algorithm/string.hpp>
+
 #include "midi++/mmc.h"
 #include "midi++/port.h"
+#include "midi++/manager.h"
 
+#include "pbd/boost_debug.h"
+#include "pbd/basename.h"
+#include "pbd/controllable_descriptor.h"
+#include "pbd/enumwriter.h"
 #include "pbd/error.h"
 #include "pbd/pathscanner.h"
 #include "pbd/pthread_utils.h"
 #include "pbd/search_path.h"
 #include "pbd/stacktrace.h"
+#include "pbd/convert.h"
+#include "pbd/clear_dir.h"
 
+#include "ardour/amp.h"
+#include "ardour/audio_diskstream.h"
+#include "ardour/audio_playlist_source.h"
+#include "ardour/audio_track.h"
 #include "ardour/audioengine.h"
-#include "ardour/configuration.h"
-#include "ardour/session.h"
-#include "ardour/session_directory.h"
-#include "ardour/session_utils.h"
-#include "ardour/session_state_utils.h"
-#include "ardour/session_metadata.h"
+#include "ardour/audiofilesource.h"
+#include "ardour/audioplaylist.h"
+#include "ardour/audioregion.h"
+#include "ardour/auditioner.h"
+#include "ardour/automation_control.h"
 #include "ardour/buffer.h"
-#include "ardour/audio_diskstream.h"
+#include "ardour/butler.h"
+#include "ardour/configuration.h"
+#include "ardour/control_protocol_manager.h"
+#include "ardour/crossfade.h"
+#include "ardour/cycle_timer.h"
+#include "ardour/directory_names.h"
+#include "ardour/filename_extensions.h"
+#include "ardour/io_processor.h"
+#include "ardour/location.h"
 #include "ardour/midi_diskstream.h"
-#include "ardour/utils.h"
-#include "ardour/audioplaylist.h"
+#include "ardour/midi_model.h"
+#include "ardour/midi_patch_manager.h"
 #include "ardour/midi_playlist.h"
-#include "ardour/smf_source.h"
-#include "ardour/audiofilesource.h"
-#include "ardour/silentfilesource.h"
-#include "ardour/sndfilesource.h"
+#include "ardour/midi_region.h"
 #include "ardour/midi_source.h"
-#include "ardour/sndfile_helpers.h"
-#include "ardour/auditioner.h"
-#include "ardour/io_processor.h"
-#include "ardour/send.h"
-#include "ardour/processor.h"
-#include "ardour/user_bundle.h"
-#include "ardour/slave.h"
-#include "ardour/tempo.h"
-#include "ardour/audio_track.h"
 #include "ardour/midi_track.h"
-#include "ardour/midi_patch_manager.h"
-#include "ardour/cycle_timer.h"
-#include "ardour/utils.h"
 #include "ardour/named_selection.h"
-#include "ardour/version.h"
-#include "ardour/location.h"
-#include "ardour/audioregion.h"
-#include "ardour/midi_region.h"
-#include "ardour/crossfade.h"
-#include "ardour/control_protocol_manager.h"
+#include "ardour/pannable.h"
+#include "ardour/processor.h"
+#include "ardour/port.h"
+#include "ardour/proxy_controllable.h"
+#include "ardour/recent_sessions.h"
 #include "ardour/region_factory.h"
+#include "ardour/route_group.h"
+#include "ardour/send.h"
+#include "ardour/session.h"
+#include "ardour/session_directory.h"
+#include "ardour/session_metadata.h"
+#include "ardour/session_state_utils.h"
+#include "ardour/session_playlists.h"
+#include "ardour/session_utils.h"
+#include "ardour/silentfilesource.h"
+#include "ardour/slave.h"
+#include "ardour/smf_source.h"
+#include "ardour/sndfile_helpers.h"
+#include "ardour/sndfilesource.h"
 #include "ardour/source_factory.h"
-#include "ardour/playlist_factory.h"
-#include "ardour/filename_extensions.h"
-#include "ardour/directory_names.h"
+#include "ardour/speakers.h"
 #include "ardour/template_utils.h"
+#include "ardour/tempo.h"
 #include "ardour/ticker.h"
-#include "ardour/route_group.h"
+#include "ardour/user_bundle.h"
+#include "ardour/utils.h"
+#include "ardour/utils.h"
+#include "ardour/version.h"
+#include "ardour/playlist_factory.h"
 
 #include "control_protocol/control_protocol.h"
 
@@ -114,6 +136,7 @@ using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
 
+/** @param snapshot_name Snapshot name, without the .ardour prefix */
 void
 Session::first_stage_init (string fullpath, string snapshot_name)
 {
@@ -131,8 +154,8 @@ Session::first_stage_init (string fullpath, string snapshot_name)
 
        _path = string(buf);
 
-       if (_path[_path.length()-1] != '/') {
-               _path += '/';
+       if (_path[_path.length()-1] != G_DIR_SEPARATOR) {
+               _path += G_DIR_SEPARATOR;
        }
 
        /* these two are just provisional settings. set_state()
@@ -148,10 +171,12 @@ Session::first_stage_init (string fullpath, string snapshot_name)
        _base_frame_rate = _current_frame_rate;
 
        _tempo_map = new TempoMap (_current_frame_rate);
-       _tempo_map->StateChanged.connect (mem_fun (*this, &Session::tempo_map_changed));
+       _tempo_map->PropertyChanged.connect_same_thread (*this, boost::bind (&Session::tempo_map_changed, this, _1));
 
 
        _non_soloed_outs_muted = false;
+       _listen_cnt = 0;
+       _solo_isolated_cnt = 0;
        g_atomic_int_set (&processing_prohibited, 0);
        _transport_speed = 0;
        _last_transport_speed = 0;
@@ -159,58 +184,52 @@ Session::first_stage_init (string fullpath, string snapshot_name)
        auto_play_legal = false;
        transport_sub_state = 0;
        _transport_frame = 0;
-       end_location = new Location (0, 0, _("end"), Location::Flags ((Location::IsMark|Location::IsEnd)));
-       start_location = new Location (0, 0, _("start"), Location::Flags ((Location::IsMark|Location::IsStart)));
+       _requested_return_frame = -1;
+       _session_range_location = 0;
        g_atomic_int_set (&_record_status, Disabled);
        loop_changing = false;
        play_loop = false;
        have_looped = false;
        _last_roll_location = 0;
+       _last_roll_or_reversal_location = 0;
        _last_record_location = 0;
        pending_locate_frame = 0;
        pending_locate_roll = false;
        pending_locate_flush = false;
-       audio_dstream_buffer_size = 0;
-       midi_dstream_buffer_size = 0;
        state_was_pending = false;
        set_next_event ();
-       outbound_mtc_smpte_frame = 0;
+       outbound_mtc_timecode_frame = 0;
        next_quarter_frame_to_send = -1;
        current_block_size = 0;
        solo_update_disabled = false;
        _have_captured = false;
        _worst_output_latency = 0;
        _worst_input_latency = 0;
-       _worst_track_latency = 0;
+       _worst_track_latency = 0;
        _state_of_the_state = StateOfTheState(CannotSave|InitialConnecting|Loading);
-
+       _was_seamless = Config->get_seamless_loop ();
        _slave = 0;
-       session_send_mmc = false;
-       session_send_mtc = false;
-       post_transport_work = PostTransportWork (0);
-       g_atomic_int_set (&butler_should_do_transport_work, 0);
+       _send_qf_mtc = false;
+       _pframes_since_last_mtc = 0;
        g_atomic_int_set (&_playback_load, 100);
        g_atomic_int_set (&_capture_load, 100);
-       g_atomic_int_set (&_playback_load_min, 100);
-       g_atomic_int_set (&_capture_load_min, 100);
        _play_range = false;
        _exporting = false;
-       _exporting_realtime = false;
-       _gain_automation_buffer = 0;
-       _pan_automation_buffer = 0;
-       _npan_buffers = 0;
        pending_abort = false;
        destructive_index = 0;
        first_file_data_format_reset = true;
        first_file_header_format_reset = true;
-       butler_thread = (pthread_t) 0;
-       //midi_thread = (pthread_t) 0;
+       post_export_sync = false;
+       midi_control_ui = 0;
+        _step_editors = 0;
+        no_questions_about_missing_files = false;
+        _speakers.reset (new Speakers);
 
        AudioDiskstream::allocate_working_buffers();
 
        /* default short fade = 15ms */
 
-       Crossfade::set_short_xfade_length ((nframes_t) floor (config.get_short_xfade_seconds() * frame_rate()));
+       Crossfade::set_short_xfade_length ((framecnt_t) floor (config.get_short_xfade_seconds() * frame_rate()));
        SndFileSource::setup_standard_crossfades (*this, frame_rate());
 
        last_mmc_step.tv_sec = 0;
@@ -220,7 +239,7 @@ Session::first_stage_init (string fullpath, string snapshot_name)
        /* click sounds are unset by default, which causes us to internal
           waveforms for clicks.
        */
-       
+
        click_length = 0;
        click_emphasis_length = 0;
        _clicking = false;
@@ -233,39 +252,39 @@ Session::first_stage_init (string fullpath, string snapshot_name)
                waiting_for_sync_offset = false;
        }
 
-       last_smpte_when = 0;
-       _smpte_offset = 0;
-       _smpte_offset_negative = true;
-       last_smpte_valid = false;
+       last_timecode_when = 0;
+       last_timecode_valid = false;
 
        sync_time_vars ();
 
        last_rr_session_dir = session_dirs.begin();
        refresh_disk_space ();
 
-       // set_default_fade (0.2, 5.0); /* steepness, millisecs */
+        /* default: assume simple stereo speaker configuration */
+
+        _speakers->setup_default_speakers (2);
 
        /* slave stuff */
 
        average_slave_delta = 1800; // !!! why 1800 ????
        have_first_delta_accumulator = false;
        delta_accumulator_cnt = 0;
-       slave_state = Stopped;
+       _slave_state = Stopped;
 
-       _engine.GraphReordered.connect (mem_fun (*this, &Session::graph_reordered));
-
-       /* These are all static "per-class" signals */
+        _solo_cut_control.reset (new ProxyControllable (_("solo cut control (dB)"), PBD::Controllable::GainLike,
+                                                        boost::bind (&RCConfiguration::set_solo_mute_gain, Config, _1),
+                                                        boost::bind (&RCConfiguration::get_solo_mute_gain, Config)));
+        add_controllable (_solo_cut_control);
 
-       RegionFactory::CheckNewRegion.connect (mem_fun (*this, &Session::add_region));
-       SourceFactory::SourceCreated.connect (mem_fun (*this, &Session::add_source));
-       PlaylistFactory::PlaylistCreated.connect (mem_fun (*this, &Session::add_playlist));
-       Processor::ProcessorCreated.connect (mem_fun (*this, &Session::add_processor));
-       NamedSelection::NamedSelectionCreated.connect (mem_fun (*this, &Session::add_named_selection));
-       AutomationList::AutomationListCreated.connect (mem_fun (*this, &Session::add_automation_list));
+       _engine.GraphReordered.connect_same_thread (*this, boost::bind (&Session::graph_reordered, this));
 
-       Controllable::Destroyed.connect (mem_fun (*this, &Session::remove_controllable));
+       /* These are all static "per-class" signals */
 
-       IO::PortCountChanged.connect (mem_fun (*this, &Session::ensure_buffers));
+       SourceFactory::SourceCreated.connect_same_thread (*this, boost::bind (&Session::add_source, this, _1));
+       PlaylistFactory::PlaylistCreated.connect_same_thread (*this, boost::bind (&Session::add_playlist, this, _1, _2));
+       AutomationList::AutomationListCreated.connect_same_thread (*this, boost::bind (&Session::add_automation_list, this, _1));
+       Controllable::Destroyed.connect_same_thread (*this, boost::bind (&Session::remove_controllable, this, _1));
+       IO::PortCountChanged.connect_same_thread (*this, boost::bind (&Session::ensure_buffers, this, _1));
 
        /* stop IO objects from doing stuff until we're ready for them */
 
@@ -274,18 +293,17 @@ Session::first_stage_init (string fullpath, string snapshot_name)
 }
 
 int
-Session::second_stage_init (bool new_session)
+Session::second_stage_init ()
 {
        AudioFileSource::set_peak_dir (_session_dir->peak_path().to_string());
 
-       if (!new_session) {
+       if (!_is_new) {
                if (load_state (_current_snapshot_name)) {
                        return -1;
                }
-               remove_empty_sounds ();
        }
 
-       if (start_butler_thread()) {
+       if (_butler->start_thread()) {
                return -1;
        }
 
@@ -293,11 +311,13 @@ Session::second_stage_init (bool new_session)
                return -1;
        }
 
+       setup_midi_machine_control ();
+
        // set_state() will call setup_raid_path(), but if it's a new session we need
        // to call setup_raid_path() here.
 
        if (state_tree) {
-               if (set_state (*state_tree->root())) {
+               if (set_state (*state_tree->root(), Stateful::loading_state_version)) {
                        return -1;
                }
        } else {
@@ -316,23 +336,22 @@ Session::second_stage_init (bool new_session)
 
        _state_of_the_state = StateOfTheState (_state_of_the_state|CannotSave|Loading);
 
-
-       _locations.changed.connect (mem_fun (this, &Session::locations_changed));
-       _locations.added.connect (mem_fun (this, &Session::locations_added));
+       _locations->changed.connect_same_thread (*this, boost::bind (&Session::locations_changed, this));
+       _locations->added.connect_same_thread (*this, boost::bind (&Session::locations_added, this, _1));
        setup_click_sounds (0);
        setup_midi_control ();
 
        /* Pay attention ... */
 
-       _engine.Halted.connect (mem_fun (*this, &Session::engine_halted));
-       _engine.Xrun.connect (mem_fun (*this, &Session::xrun_recovery));
+       _engine.Halted.connect_same_thread (*this, boost::bind (&Session::engine_halted, this));
+       _engine.Xrun.connect_same_thread (*this, boost::bind (&Session::xrun_recovery, this));
 
        try {
-               when_engine_running();
+               when_engine_running ();
        }
 
        /* handle this one in a different way than all others, so that its clear what happened */
-       
+
        catch (AudioEngine::PortRegistrationFailure& err) {
                error << err.what() << endmsg;
                return -1;
@@ -346,22 +365,19 @@ Session::second_stage_init (bool new_session)
 
        send_full_time_code (0);
        _engine.transport_locate (0);
-       deliver_mmc (MIDI::MachineControl::cmdMmcReset, 0);
-       deliver_mmc (MIDI::MachineControl::cmdLocate, 0);
-       
-       MidiClockTicker::instance().set_session(*this);
-       MIDI::Name::MidiPatchManager::instance().set_session(*this);
-
-       /* initial program change will be delivered later; see ::config_changed() */
 
-       BootMessage (_("Reset Control Protocols"));
+       MIDI::Manager::instance()->mmc()->send (MIDI::MachineControlCommand (MIDI::MachineControl::cmdMmcReset));
+       MIDI::Manager::instance()->mmc()->send (MIDI::MachineControlCommand (Timecode::Time ()));
 
-       ControlProtocolManager::instance().set_session (*this);
+       MidiClockTicker::instance().set_session (this);
+       MIDI::Name::MidiPatchManager::instance().set_session (this);
 
-       config.set_end_marker_is_free (new_session);
+       /* initial program change will be delivered later; see ::config_changed() */
 
        _state_of_the_state = Clean;
-       
+
+       Port::set_connecting_blocked (false);
+
        DirtyChanged (); /* EMIT SIGNAL */
 
        if (state_was_pending) {
@@ -369,7 +385,7 @@ Session::second_stage_init (bool new_session)
                remove_pending_capture_state ();
                state_was_pending = false;
        }
-       
+
        BootMessage (_("Session loading complete"));
 
        return 0;
@@ -383,7 +399,7 @@ Session::raid_path () const
        for (vector<space_and_path>::const_iterator i = session_dirs.begin(); i != session_dirs.end(); ++i) {
                raid_search_path += sys::path((*i).path);
        }
-       
+
        return raid_search_path.to_string ();
 }
 
@@ -393,7 +409,7 @@ Session::setup_raid_path (string path)
        if (path.empty()) {
                return;
        }
-       
+
        space_and_path sp;
        string fspath;
 
@@ -414,14 +430,21 @@ Session::setup_raid_path (string path)
                midi_search_path += sdir.midi_path ();
        }
 
-       // set the search path for each data type
-       FileSource::set_search_path (DataType::AUDIO, sound_search_path.to_string ());
-       SMFSource::set_search_path (DataType::MIDI, midi_search_path.to_string ());
-
        // reset the round-robin soundfile path thingie
        last_rr_session_dir = session_dirs.begin();
 }
 
+bool
+Session::path_is_within_session (const std::string& path)
+{
+       for (vector<space_and_path>::const_iterator i = session_dirs.begin(); i != session_dirs.end(); ++i) {
+               if (path.find ((*i).path) == 0) {
+                       return true;
+               }
+       }
+       return false;
+}
+
 int
 Session::ensure_subdirs ()
 {
@@ -440,7 +463,7 @@ Session::ensure_subdirs ()
                error << string_compose(_("Session: cannot create session sounds dir \"%1\" (%2)"), dir, strerror (errno)) << endmsg;
                return -1;
        }
-       
+
        dir = session_directory().midi_path().to_string();
 
        if (g_mkdir_with_parents (dir.c_str(), 0755) < 0) {
@@ -448,7 +471,7 @@ Session::ensure_subdirs ()
                return -1;
        }
 
-       dir = session_directory().dead_sound_path().to_string();
+       dir = session_directory().dead_path().to_string();
 
        if (g_mkdir_with_parents (dir.c_str(), 0755) < 0) {
                error << string_compose(_("Session: cannot create session dead sounds folder \"%1\" (%2)"), dir, strerror (errno)) << endmsg;
@@ -469,13 +492,22 @@ Session::ensure_subdirs ()
                return -1;
        }
 
+       dir = plugins_dir ();
+
+       if (g_mkdir_with_parents (dir.c_str(), 0755) < 0) {
+               error << string_compose(_("Session: cannot create session plugins folder \"%1\" (%2)"), dir, strerror (errno)) << endmsg;
+               return -1;
+       }
+
        return 0;
 }
 
+/** @param session_template directory containing session template, or empty.
+ *  Caller must not hold process lock.
+ */
 int
-Session::create (bool& new_session, const string& mix_template, nframes_t initial_length)
+Session::create (const string& session_template, BusProfile* bus_profile)
 {
-
        if (g_mkdir_with_parents (_path.c_str(), 0755) < 0) {
                error << string_compose(_("Session: cannot create session folder \"%1\" (%2)"), _path, strerror (errno)) << endmsg;
                return -1;
@@ -485,91 +517,118 @@ Session::create (bool& new_session, const string& mix_template, nframes_t initia
                return -1;
        }
 
-       /* check new_session so we don't overwrite an existing one */
+       _writable = exists_and_writable (sys::path (_path));
 
-       if (!mix_template.empty()) {
-               std::string in_path = mix_template;
+       if (!session_template.empty()) {
+               std::string in_path = session_template_dir_to_file (session_template);
 
                ifstream in(in_path.c_str());
 
-               if (in){
+               if (in) {
                        string out_path = _path;
                        out_path += _name;
                        out_path += statefile_suffix;
 
                        ofstream out(out_path.c_str());
 
-                       if (out){
+                       if (out) {
                                out << in.rdbuf();
+                                _is_new = false;
 
-                               // okay, session is set up.  Treat like normal saved
-                               // session from now on.
-
-                               new_session = false;
+                               /* Copy plugin state files from template to new session */
+                               sys::path template_plugins = session_template;
+                               template_plugins /= X_("plugins");
+                               sys::copy_files (template_plugins, plugins_dir ());
+                               
                                return 0;
 
                        } else {
-                               error << string_compose (_("Could not open %1 for writing mix template"), out_path) 
+                               error << string_compose (_("Could not open %1 for writing session template"), out_path)
                                        << endmsg;
                                return -1;
                        }
 
                } else {
-                       error << string_compose (_("Could not open mix template %1 for reading"), in_path) 
+                       error << string_compose (_("Could not open session template %1 for reading"), in_path)
                                << endmsg;
                        return -1;
                }
 
        }
-       
+
        /* Instantiate metadata */
-       
+
        _metadata = new SessionMetadata ();
 
        /* set initial start + end point */
 
-       start_location->set_end (0);
-       _locations.add (start_location);
+       _state_of_the_state = Clean;
 
-       end_location->set_end (initial_length);
-       _locations.add (end_location);
+        /* set up Master Out and Control Out if necessary */
 
-       _state_of_the_state = Clean;
+        if (bus_profile) {
 
-       save_state ("");
+               RouteList rl;
+               int control_id = 1;
+                ChanCount count(DataType::AUDIO, bus_profile->master_out_channels);
 
-       return 0;
-}
+               if (bus_profile->master_out_channels) {
+                       boost::shared_ptr<Route> r (new Route (*this, _("master"), Route::MasterOut, DataType::AUDIO));
+                        if (r->init ()) {
+                                return -1;
+                        }
+#ifdef BOOST_SP_ENABLE_DEBUG_HOOKS
+                       // boost_debug_shared_ptr_mark_interesting (r.get(), "Route");
+#endif
+                       {
+                               Glib::Mutex::Lock lm (AudioEngine::instance()->process_lock ());
+                               r->input()->ensure_io (count, false, this);
+                               r->output()->ensure_io (count, false, this);
+                       }
+                       r->set_remote_control_id (control_id++);
 
+                       rl.push_back (r);
 
-int
-Session::load_diskstreams (const XMLNode& node)
-{
-       XMLNodeList          clist;
-       XMLNodeConstIterator citer;
-       
-       clist = node.children();
+                        if (Config->get_use_monitor_bus()) {
+                               boost::shared_ptr<Route> r (new Route (*this, _("monitor"), Route::MonitorOut, DataType::AUDIO));
+                                if (r->init ()) {
+                                        return -1;
+                                }
+#ifdef BOOST_SP_ENABLE_DEBUG_HOOKS
+                                // boost_debug_shared_ptr_mark_interesting (r.get(), "Route");
+#endif
+                               {
+                                       Glib::Mutex::Lock lm (AudioEngine::instance()->process_lock ());
+                                       r->input()->ensure_io (count, false, this);
+                                       r->output()->ensure_io (count, false, this);
+                               }
+                                r->set_remote_control_id (control_id);
 
-       for (citer = clist.begin(); citer != clist.end(); ++citer) {
+                                rl.push_back (r);
+                        }
 
-               try {
-                       /* diskstreams added automatically by DiskstreamCreated handler */
-                       if ((*citer)->name() == "AudioDiskstream" || (*citer)->name() == "DiskStream") {
-                               boost::shared_ptr<AudioDiskstream> dstream (new AudioDiskstream (*this, **citer));
-                               add_diskstream (dstream);
-                       } else if ((*citer)->name() == "MidiDiskstream") {
-                               boost::shared_ptr<MidiDiskstream> dstream (new MidiDiskstream (*this, **citer));
-                               add_diskstream (dstream);
-                       } else {
-                               error << _("Session: unknown diskstream type in XML") << endmsg;
-                       }
-               } 
-               
-               catch (failed_constructor& err) {
-                       error << _("Session: could not load diskstream via XML state") << endmsg;
-                       return -1;
+               } else {
+                       /* prohibit auto-connect to master, because there isn't one */
+                       bus_profile->output_ac = AutoConnectOption (bus_profile->output_ac & ~AutoConnectMaster);
+               }
+
+               if (!rl.empty()) {
+                       add_routes (rl, false, false);
                }
-       }
+
+                /* this allows the user to override settings with an environment variable.
+                 */
+
+                if (no_auto_connect()) {
+                        bus_profile->input_ac = AutoConnectOption (0);
+                        bus_profile->output_ac = AutoConnectOption (0);
+                }
+
+                Config->set_input_auto_connect (bus_profile->input_ac);
+                Config->set_output_auto_connect (bus_profile->output_ac);
+        }
+
+       save_state ("");
 
        return 0;
 }
@@ -586,8 +645,8 @@ void
 Session::remove_pending_capture_state ()
 {
        sys::path pending_state_file_path(_session_dir->root_path());
-       
-       pending_state_file_path /= _current_snapshot_name + pending_suffix;
+
+       pending_state_file_path /= legalize_for_path (_current_snapshot_name) + pending_suffix;
 
        try
        {
@@ -601,7 +660,8 @@ Session::remove_pending_capture_state ()
 }
 
 /** Rename a state file.
- * @param snapshot_name Snapshot name.
+ *  @param old_name Old snapshot name.
+ *  @param new_name New snapshot name.
  */
 void
 Session::rename_state (string old_name, string new_name)
@@ -611,8 +671,8 @@ Session::rename_state (string old_name, string new_name)
                return;
        }
 
-       const string old_xml_filename = old_name + statefile_suffix;
-       const string new_xml_filename = new_name + statefile_suffix;
+       const string old_xml_filename = legalize_for_path (old_name) + statefile_suffix;
+       const string new_xml_filename = legalize_for_path (new_name) + statefile_suffix;
 
        const sys::path old_xml_path = _session_dir->root_path() / old_xml_filename;
        const sys::path new_xml_path = _session_dir->root_path() / new_xml_filename;
@@ -629,7 +689,7 @@ Session::rename_state (string old_name, string new_name)
 }
 
 /** Remove a state file.
- * @param snapshot_name Snapshot name.
+ *  @param snapshot_name Snapshot name.
  */
 void
 Session::remove_state (string snapshot_name)
@@ -641,7 +701,7 @@ Session::remove_state (string snapshot_name)
 
        sys::path xml_path(_session_dir->root_path());
 
-       xml_path /= snapshot_name + statefile_suffix;
+       xml_path /= legalize_for_path (snapshot_name) + statefile_suffix;
 
        if (!create_backup_file (xml_path)) {
                // don't remove it if a backup can't be made
@@ -653,38 +713,96 @@ Session::remove_state (string snapshot_name)
        sys::remove (xml_path);
 }
 
+#ifdef HAVE_JACK_SESSION
+void
+Session::jack_session_event (jack_session_event_t * event)
+{
+        char timebuf[128];
+        time_t n;
+        struct tm local_time;
+
+        time (&n);
+        localtime_r (&n, &local_time);
+        strftime (timebuf, sizeof(timebuf), "JS_%FT%T", &local_time);
+
+        if (event->type == JackSessionSaveTemplate)
+        {
+                if (save_template( timebuf )) {
+                        event->flags = JackSessionSaveError;
+                } else {
+                        string cmd ("ardour3 -P -U ");
+                        cmd += event->client_uuid;
+                        cmd += " -T ";
+                        cmd += timebuf;
+
+                        event->command_line = strdup (cmd.c_str());
+                }
+        }
+        else
+        {
+                if (save_state (timebuf)) {
+                        event->flags = JackSessionSaveError;
+                } else {
+                        sys::path xml_path (_session_dir->root_path());
+                        xml_path /= legalize_for_path (timebuf) + statefile_suffix;
+
+                        string cmd ("ardour3 -P -U ");
+                        cmd += event->client_uuid;
+                        cmd += " \"";
+                        cmd += xml_path.to_string();
+                        cmd += '\"';
+
+                        event->command_line = strdup (cmd.c_str());
+                }
+        }
+
+       jack_session_reply (_engine.jack(), event);
+
+       if (event->type == JackSessionSaveAndQuit) {
+               Quit (); /* EMIT SIGNAL */
+       }
+
+       jack_session_event_free( event );
+}
+#endif
+
+/** @param snapshot_name Name to save under, without .ardour / .pending prefix */
 int
-Session::save_state (string snapshot_name, bool pending)
+Session::save_state (string snapshot_name, bool pending, bool switch_to_snapshot)
 {
        XMLTree tree;
        sys::path xml_path(_session_dir->root_path());
 
-       if (_state_of_the_state & CannotSave) {
+       if (!_writable || (_state_of_the_state & CannotSave)) {
                return 1;
        }
 
        if (!_engine.connected ()) {
-               error << _("Ardour's audio engine is not connected and state saving would lose all I/O connections. Session not saved")
+               error << string_compose (_("the %1 audio engine is not connected and state saving would lose all I/O connections. Session not saved"),
+                                         PROGRAM_NAME)
                      << endmsg;
                return 1;
        }
 
        /* tell sources we're saving first, in case they write out to a new file
         * which should be saved with the state rather than the old one */
-       for (SourceMap::const_iterator i = sources.begin(); i != sources.end(); ++i)
+       for (SourceMap::const_iterator i = sources.begin(); i != sources.end(); ++i) {
                i->second->session_saved();
+        }
 
        tree.set_root (&get_state());
 
        if (snapshot_name.empty()) {
                snapshot_name = _current_snapshot_name;
-       }
+       } else if (switch_to_snapshot) {
+                _current_snapshot_name = snapshot_name;
+        }
 
        if (!pending) {
 
                /* proper save: use statefile_suffix (.ardour in English) */
-               
-               xml_path /= snapshot_name + statefile_suffix;
+
+               xml_path /= legalize_for_path (snapshot_name) + statefile_suffix;
 
                /* make a backup copy of the old file */
 
@@ -696,12 +814,12 @@ Session::save_state (string snapshot_name, bool pending)
        } else {
 
                /* pending save: use pending_suffix (.pending in English) */
-               xml_path /= snapshot_name + pending_suffix;
+               xml_path /= legalize_for_path (snapshot_name) + pending_suffix;
        }
 
        sys::path tmp_path(_session_dir->root_path());
 
-       tmp_path /= snapshot_name + temp_suffix;
+       tmp_path /= legalize_for_path (snapshot_name) + temp_suffix;
 
        // cerr << "actually writing state to " << xml_path.to_string() << endl;
 
@@ -712,7 +830,7 @@ Session::save_state (string snapshot_name, bool pending)
 
        } else {
 
-               if (rename (tmp_path.to_string().c_str(), xml_path.to_string().c_str()) != 0) {
+               if (::rename (tmp_path.to_string().c_str(), xml_path.to_string().c_str()) != 0) {
                        error << string_compose (_("could not rename temporary session file %1 to %2"),
                                        tmp_path.to_string(), xml_path.to_string()) << endmsg;
                        sys::remove (tmp_path);
@@ -727,7 +845,7 @@ Session::save_state (string snapshot_name, bool pending)
                bool was_dirty = dirty();
 
                _state_of_the_state = StateOfTheState (_state_of_the_state & ~Dirty);
-               
+
                if (was_dirty) {
                        DirtyChanged (); /* EMIT SIGNAL */
                }
@@ -742,9 +860,9 @@ int
 Session::restore_state (string snapshot_name)
 {
        if (load_state (snapshot_name) == 0) {
-               set_state (*state_tree->root());
+               set_state (*state_tree->root(), Stateful::loading_state_version);
        }
-       
+
        return 0;
 }
 
@@ -759,31 +877,38 @@ Session::load_state (string snapshot_name)
        /* check for leftover pending state from a crashed capture attempt */
 
        sys::path xmlpath(_session_dir->root_path());
-       xmlpath /= snapshot_name + pending_suffix;
+       xmlpath /= legalize_for_path (snapshot_name) + pending_suffix;
 
        if (sys::exists (xmlpath)) {
 
                /* there is pending state from a crashed capture attempt */
 
-               if (AskAboutPendingState()) {
+                boost::optional<int> r = AskAboutPendingState();
+               if (r.get_value_or (1)) {
                        state_was_pending = true;
-               } 
-       } 
+               }
+       }
 
        if (!state_was_pending) {
                xmlpath = _session_dir->root_path();
-               xmlpath /= snapshot_name + statefile_suffix;
-       }
-       
-       if (!sys::exists (xmlpath)) {
-               error << string_compose(_("%1: session state information file \"%2\" doesn't exist!"), _name, xmlpath.to_string()) << endmsg;
-               return 1;
+               xmlpath /= snapshot_name;
        }
 
+        if (!sys::exists (xmlpath)) {
+                xmlpath = _session_dir->root_path();
+                xmlpath /= legalize_for_path (snapshot_name) + statefile_suffix;
+                if (!sys::exists (xmlpath)) {
+                        error << string_compose(_("%1: session state information file \"%2\" doesn't exist!"), _name, xmlpath.to_string()) << endmsg;
+                        return 1;
+                }
+        }
+
        state_tree = new XMLTree;
 
        set_dirty();
 
+       _writable = exists_and_writable (xmlpath);
+
        if (!state_tree->read (xmlpath.to_string())) {
                error << string_compose(_("Could not understand ardour file %1"), xmlpath.to_string()) << endmsg;
                delete state_tree;
@@ -792,41 +917,41 @@ Session::load_state (string snapshot_name)
        }
 
        XMLNode& root (*state_tree->root());
-       
+
        if (root.name() != X_("Session")) {
-               error << string_compose (_("Session file %1 is not an Ardour session"), xmlpath.to_string()) << endmsg;
+               error << string_compose (_("Session file %1 is not a session"), xmlpath.to_string()) << endmsg;
                delete state_tree;
                state_tree = 0;
                return -1;
        }
 
        const XMLProperty* prop;
-       bool is_old = false; // session is _very_ old (pre-2.0)
 
        if ((prop = root.property ("version")) == 0) {
                /* no version implies very old version of Ardour */
-               is_old = true;
+               Stateful::loading_state_version = 1000;
        } else {
-               int major_version;
-               major_version = atoi (prop->value().c_str()); // grab just the first number before the period
-               if (major_version < 2) {
-                       is_old = true;
-               }
+               int major;
+               int minor;
+               int micro;
+
+               sscanf (prop->value().c_str(), "%d.%d.%d", &major, &minor, &micro);
+               Stateful::loading_state_version = (major * 1000) + minor;
        }
 
-       if (is_old) {
+       if (Stateful::loading_state_version < CURRENT_SESSION_FILE_VERSION) {
 
                sys::path backup_path(_session_dir->root_path());
 
-               backup_path /= snapshot_name + "-1" + statefile_suffix;
+               backup_path /= legalize_for_path (snapshot_name) + "-1" + statefile_suffix;
 
                // only create a backup once
                if (sys::exists (backup_path)) {
                        return 0;
                }
 
-               info << string_compose (_("Copying old session file %1 to %2\nUse %2 with Ardour versions before 2.0 from now on"),
-                                       xmlpath.to_string(), backup_path.to_string()
+               info << string_compose (_("Copying old session file %1 to %2\nUse %2 with %3 versions before 2.0 from now on"),
+                                       xmlpath.to_string(), backup_path.to_string(), PROGRAM_NAME)
                     << endmsg;
 
                try
@@ -849,15 +974,7 @@ int
 Session::load_options (const XMLNode& node)
 {
        LocaleGuard lg (X_("POSIX"));
-
        config.set_variables (node);
-
-       /* now reset MIDI ports because the session can have its own 
-          MIDI configuration.
-       */
-
-       setup_midi ();
-
        return 0;
 }
 
@@ -872,9 +989,9 @@ Session::get_template()
 {
        /* if we don't disable rec-enable, diskstreams
           will believe they need to store their capture
-          sources in their state node. 
+          sources in their state node.
        */
-       
+
        disable_record (false);
 
        return state(false);
@@ -890,13 +1007,13 @@ Session::state(bool full_state)
        char buf[16];
        snprintf(buf, sizeof(buf), "%d.%d.%d", libardour3_major_version, libardour3_minor_version, libardour3_micro_version);
        node->add_property("version", string(buf));
-               
+
        /* store configuration settings */
 
        if (full_state) {
-       
+
                node->add_property ("name", _name);
-               snprintf (buf, sizeof (buf), "%" PRId32, _nominal_frame_rate);
+               snprintf (buf, sizeof (buf), "%" PRId64, _nominal_frame_rate);
                node->add_property ("sample-rate", buf);
 
                if (session_dirs.size() > 1) {
@@ -923,17 +1040,22 @@ Session::state(bool full_state)
                                ++next;
                                ++i;
                        }
-                       
+
                        child = node->add_child ("Path");
                        child->add_content (p);
                }
        }
 
        /* save the ID counter */
-       
+
        snprintf (buf, sizeof (buf), "%" PRIu64, ID::counter());
        node->add_property ("id-counter", buf);
 
+       /* save the event ID counter */
+
+       snprintf (buf, sizeof (buf), "%d", Evoral::event_id_counter());
+       node->add_property ("event-counter", buf);
+
        /* various options */
 
        node->add_child_nocopy (config.get_variables ());
@@ -946,64 +1068,69 @@ Session::state(bool full_state)
                Glib::Mutex::Lock sl (source_lock);
 
                for (SourceMap::iterator siter = sources.begin(); siter != sources.end(); ++siter) {
-                       
-                       /* Don't save information about non-destructive file sources that are empty */
-                       /* FIXME: MIDI breaks if this is made FileSource like it should be... */
-                       
-                       boost::shared_ptr<AudioFileSource> fs;
-                       if ((fs = boost::dynamic_pointer_cast<AudioFileSource> (siter->second)) != 0) {
+
+                       /* Don't save information about non-file Sources, or
+                        * about non-destructive file sources that are empty
+                        * and unused by any regions.
+                        */
+
+                       boost::shared_ptr<FileSource> fs;
+
+                       if ((fs = boost::dynamic_pointer_cast<FileSource> (siter->second)) != 0) {
+
                                if (!fs->destructive()) {
-                                       if (fs->length(fs->timeline_position()) == 0) {
+                                       if (fs->empty() && !fs->used()) {
                                                continue;
                                        }
                                }
+
+                               child->add_child_nocopy (siter->second->get_state());
                        }
-                       
-                       child->add_child_nocopy (siter->second->get_state());
                }
        }
 
        child = node->add_child ("Regions");
 
-       if (full_state) { 
+       if (full_state) {
                Glib::Mutex::Lock rl (region_lock);
-
-               for (RegionList::const_iterator i = regions.begin(); i != regions.end(); ++i) {
-                       
-                       /* only store regions not attached to playlists */
-
-                       if (i->second->playlist() == 0) {
-                               child->add_child_nocopy (i->second->state (true));
-                       }
-               }
-       }
-
-       child = node->add_child ("DiskStreams");
-
-       { 
-               boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
-               for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
-                       if (!(*i)->hidden()) {
-                               child->add_child_nocopy ((*i)->get_state());
+                const RegionFactory::RegionMap& region_map (RegionFactory::all_regions());
+                for (RegionFactory::RegionMap::const_iterator i = region_map.begin(); i != region_map.end(); ++i) {
+                        boost::shared_ptr<Region> r = i->second;
+                        /* only store regions not attached to playlists */
+                        if (r->playlist() == 0) {
+                                child->add_child_nocopy (r->state ());
+                        }
+                }
+
+               RegionFactory::CompoundAssociations& cassocs (RegionFactory::compound_associations());
+
+               if (!cassocs.empty()) {
+                       XMLNode* ca = node->add_child (X_("CompoundAssociations"));
+
+                       for (RegionFactory::CompoundAssociations::iterator i = cassocs.begin(); i != cassocs.end(); ++i) {
+                               char buf[64];
+                               XMLNode* can = new XMLNode (X_("CompoundAssociation"));
+                               i->first->id().print (buf, sizeof (buf));
+                               can->add_property (X_("copy"), buf);
+                               i->second->id().print (buf, sizeof (buf));
+                               can->add_property (X_("original"), buf);
+                               ca->add_child_nocopy (*can);
                        }
                }
        }
 
        if (full_state) {
-               node->add_child_nocopy (_locations.get_state());
+               node->add_child_nocopy (_locations->get_state());
        } else {
                // for a template, just create a new Locations, populate it
                // with the default start and end, and get the state for that.
-               Locations loc;
-               Location* start = new Location(0, 0, _("start"), Location::Flags ((Location::IsMark|Location::IsStart)));
-               Location* end = new Location(0, 0, _("end"), Location::Flags ((Location::IsMark|Location::IsEnd)));
-               start->set_end(0);
-               loc.add (start);
-               end->set_end(compute_initial_length());
-               loc.add (end);
+               Locations loc (*this);
+               Location* range = new Location (*this, 0, 0, _("session"), Location::IsSessionRange);
+               range->set (max_framepos, 0);
+               loc.add (range);
                node->add_child_nocopy (loc.get_state());
        }
-       
+
        child = node->add_child ("Bundles");
        {
                boost::shared_ptr<BundleList> bundles = _bundles.reader ();
@@ -1018,11 +1145,17 @@ Session::state(bool full_state)
        child = node->add_child ("Routes");
        {
                boost::shared_ptr<RouteList> r = routes.reader ();
-               
+
                RoutePublicOrderSorter cmp;
                RouteList public_order (*r);
                public_order.sort (cmp);
-               
+
+                /* the sort should have put control outs first */
+
+                if (_monitor_out) {
+                        assert (_monitor_out == public_order.front());
+                }
+
                for (RouteList::iterator i = public_order.begin(); i != public_order.end(); ++i) {
                        if (!(*i)->is_hidden()) {
                                if (full_state) {
@@ -1034,44 +1167,13 @@ Session::state(bool full_state)
                }
        }
 
-       
-       child = node->add_child ("EditGroups");
-       for (list<RouteGroup *>::iterator i = edit_groups.begin(); i != edit_groups.end(); ++i) {
-               child->add_child_nocopy ((*i)->get_state());
-       }
+       playlists->add_state (node, full_state);
 
-       child = node->add_child ("MixGroups");
-       for (list<RouteGroup *>::iterator i = mix_groups.begin(); i != mix_groups.end(); ++i) {
+       child = node->add_child ("RouteGroups");
+       for (list<RouteGroup *>::iterator i = _route_groups.begin(); i != _route_groups.end(); ++i) {
                child->add_child_nocopy ((*i)->get_state());
        }
 
-       child = node->add_child ("Playlists");
-       for (PlaylistList::iterator i = playlists.begin(); i != playlists.end(); ++i) {
-               if (!(*i)->hidden()) {
-                       if (!(*i)->empty()) {
-                               if (full_state) {
-                                       child->add_child_nocopy ((*i)->get_state());
-                               } else {
-                                       child->add_child_nocopy ((*i)->get_template());
-                               }
-                       }
-               }
-       }
-
-       child = node->add_child ("UnusedPlaylists");
-       for (PlaylistList::iterator i = unused_playlists.begin(); i != unused_playlists.end(); ++i) {
-               if (!(*i)->hidden()) {
-                       if (!(*i)->empty()) {
-                               if (full_state) {
-                                       child->add_child_nocopy ((*i)->get_state());
-                               } else {
-                                       child->add_child_nocopy ((*i)->get_template());
-                               }
-                       }
-               }
-       }
-       
-       
        if (_click_io) {
                child = node->add_child ("Click");
                child->add_child_nocopy (_click_io->state (full_state));
@@ -1082,12 +1184,12 @@ Session::state(bool full_state)
                for (NamedSelectionList::iterator i = named_selections.begin(); i != named_selections.end(); ++i) {
                        if (full_state) {
                                child->add_child_nocopy ((*i)->get_state());
-                       } 
+                       }
                }
        }
 
+        node->add_child_nocopy (_speakers->get_state());
        node->add_child_nocopy (_tempo_map->get_state());
-
        node->add_child_nocopy (get_control_protocol_state());
 
        if (_extra_xml) {
@@ -1105,7 +1207,7 @@ Session::get_control_protocol_state ()
 }
 
 int
-Session::set_state (const XMLNode& node)
+Session::set_state (const XMLNode& node, int version)
 {
        XMLNodeList nlist;
        XMLNode* child;
@@ -1113,12 +1215,16 @@ Session::set_state (const XMLNode& node)
        int ret = -1;
 
        _state_of_the_state = StateOfTheState (_state_of_the_state|CannotSave);
-       
-       if (node.name() != X_("Session")){
+
+       if (node.name() != X_("Session")) {
                fatal << _("programming error: Session: incorrect XML node sent to set_state()") << endmsg;
                return -1;
        }
 
+       if ((prop = node.property ("version")) != 0) {
+               version = atoi (prop->value ()) * 1000;
+       }
+
        if ((prop = node.property ("name")) != 0) {
                _name = prop->value ();
        }
@@ -1128,7 +1234,8 @@ Session::set_state (const XMLNode& node)
                _nominal_frame_rate = atoi (prop->value());
 
                if (_nominal_frame_rate != _current_frame_rate) {
-                       if (AskAboutSampleRateMismatch (_nominal_frame_rate, _current_frame_rate)) {
+                        boost::optional<int> r = AskAboutSampleRateMismatch (_nominal_frame_rate, _current_frame_rate);
+                       if (r.get_value_or (0)) {
                                return -1;
                        }
                }
@@ -1150,31 +1257,13 @@ Session::set_state (const XMLNode& node)
                ID::init_counter (now);
        }
 
-       
-       IO::disable_connecting ();
+        if ((prop = node.property (X_("event-counter"))) != 0) {
+                Evoral::init_event_id_counter (atoi (prop->value()));
+        }
 
-       /* Object loading order:
-
-       Path
-       Extra
-       Options/Config
-       MIDI Control // relies on data from Options/Config
-       Metadata
-       Locations
-       Sources
-       AudioRegions
-       AudioDiskstreams
-       Connections
-       Routes
-       EditGroups
-       MixGroups
-       Click
-       ControlProtocols
-       */
+       IO::disable_connecting ();
 
-       if ((child = find_named_node (node, "Extra")) != 0) {
-               _extra_xml = new XMLNode (*child);
-       }
+       Stateful::save_extra_xml (node);
 
        if (((child = find_named_node (node, "Options")) != 0)) { /* old style */
                load_options (*child);
@@ -1184,53 +1273,56 @@ Session::set_state (const XMLNode& node)
                error << _("Session: XML state has no options section") << endmsg;
        }
 
-       if (use_config_midi_ports ()) {
+       if (version >= 3000) {
+               if ((child = find_named_node (node, "Metadata")) == 0) {
+                       warning << _("Session: XML state has no metadata section") << endmsg;
+               } else if (_metadata->set_state (*child, version)) {
+                       goto out;
+               }
+       }
+
+        if ((child = find_named_node (node, X_("Speakers"))) != 0) {
+                _speakers->set_state (*child, version);
+        }
+
+       if ((child = find_named_node (node, "Sources")) == 0) {
+               error << _("Session: XML state has no sources section") << endmsg;
+               goto out;
+       } else if (load_sources (*child)) {
+               goto out;
        }
 
-       if ((child = find_named_node (node, "Metadata")) == 0) {
-               warning << _("Session: XML state has no metadata section (2.0 session?)") << endmsg;
-       } else if (_metadata->set_state (*child)) {
+       if ((child = find_named_node (node, "TempoMap")) == 0) {
+               error << _("Session: XML state has no Tempo Map section") << endmsg;
+               goto out;
+       } else if (_tempo_map->set_state (*child, version)) {
                goto out;
        }
 
        if ((child = find_named_node (node, "Locations")) == 0) {
                error << _("Session: XML state has no locations section") << endmsg;
                goto out;
-       } else if (_locations.set_state (*child)) {
+       } else if (_locations->set_state (*child, version)) {
                goto out;
        }
 
        Location* location;
 
-       if ((location = _locations.auto_loop_location()) != 0) {
+       if ((location = _locations->auto_loop_location()) != 0) {
                set_auto_loop_location (location);
        }
 
-       if ((location = _locations.auto_punch_location()) != 0) {
+       if ((location = _locations->auto_punch_location()) != 0) {
                set_auto_punch_location (location);
        }
 
-       if ((location = _locations.end_location()) == 0) {
-               _locations.add (end_location);
-       } else {
-               delete end_location;
-               end_location = location;
-       }
-
-       if ((location = _locations.start_location()) == 0) {
-               _locations.add (start_location);
-       } else {
-               delete start_location;
-               start_location = location;
+       if ((location = _locations->session_range_location()) != 0) {
+               delete _session_range_location;
+               _session_range_location = location;
        }
 
-       AudioFileSource::set_header_position_offset (start_location->start());
-
-       if ((child = find_named_node (node, "Sources")) == 0) {
-               error << _("Session: XML state has no sources section") << endmsg;
-               goto out;
-       } else if (load_sources (*child)) {
-               goto out;
+       if (_session_range_location) {
+               AudioFileSource::set_header_position_offset (_session_range_location->start());
        }
 
        if ((child = find_named_node (node, "Regions")) == 0) {
@@ -1243,71 +1335,89 @@ Session::set_state (const XMLNode& node)
        if ((child = find_named_node (node, "Playlists")) == 0) {
                error << _("Session: XML state has no playlists section") << endmsg;
                goto out;
-       } else if (load_playlists (*child)) {
+       } else if (playlists->load (*this, *child)) {
                goto out;
        }
 
        if ((child = find_named_node (node, "UnusedPlaylists")) == 0) {
                // this is OK
-       } else if (load_unused_playlists (*child)) {
+       } else if (playlists->load_unused (*this, *child)) {
                goto out;
        }
-       
+
+       if ((child = find_named_node (node, "CompoundAssociations")) != 0) {
+               if (load_compounds (*child)) {
+                       goto out;
+               }
+       }
+
        if ((child = find_named_node (node, "NamedSelections")) != 0) {
                if (load_named_selections (*child)) {
                        goto out;
                }
        }
 
-       if ((child = find_named_node (node, "DiskStreams")) == 0) {
-               error << _("Session: XML state has no diskstreams section") << endmsg;
-               goto out;
-       } else if (load_diskstreams (*child)) {
-               goto out;
+       if (version >= 3000) {
+               if ((child = find_named_node (node, "Bundles")) == 0) {
+                       warning << _("Session: XML state has no bundles section") << endmsg;
+                       //goto out;
+               } else {
+                       /* We can't load Bundles yet as they need to be able
+                          to convert from port names to Port objects, which can't happen until
+                          later */
+                       _bundle_xml_node = new XMLNode (*child);
+               }
        }
 
-       if ((child = find_named_node (node, "Bundles")) == 0) {
-               warning << _("Session: XML state has no bundles section (2.0 session?)") << endmsg;
-               //goto out;
-       } else {
-               /* We can't load Bundles yet as they need to be able
-                  to convert from port names to Port objects, which can't happen until
-                  later */
-               _bundle_xml_node = new XMLNode (*child);
-       }
-       
-       if ((child = find_named_node (node, "EditGroups")) == 0) {
-               error << _("Session: XML state has no edit groups section") << endmsg;
-               goto out;
-       } else if (load_edit_groups (*child)) {
-               goto out;
+       if (version < 3000) {
+               if ((child = find_named_node (node, X_("DiskStreams"))) == 0) {
+                       error << _("Session: XML state has no diskstreams section") << endmsg;
+                       goto out;
+               } else if (load_diskstreams_2X (*child, version)) {
+                       goto out;
+               }
        }
 
-       if ((child = find_named_node (node, "MixGroups")) == 0) {
-               error << _("Session: XML state has no mix groups section") << endmsg;
+       if ((child = find_named_node (node, "Routes")) == 0) {
+               error << _("Session: XML state has no routes section") << endmsg;
                goto out;
-       } else if (load_mix_groups (*child)) {
+       } else if (load_routes (*child, version)) {
                goto out;
        }
 
-       if ((child = find_named_node (node, "TempoMap")) == 0) {
-               error << _("Session: XML state has no Tempo Map section") << endmsg;
-               goto out;
-       } else if (_tempo_map->set_state (*child)) {
-               goto out;
-       }
+       /* our diskstreams list is no longer needed as they are now all owned by their Route */
+       _diskstreams_2X.clear ();
 
-       if ((child = find_named_node (node, "Routes")) == 0) {
-               error << _("Session: XML state has no routes section") << endmsg;
-               goto out;
-       } else if (load_routes (*child)) {
-               goto out;
+       if (version >= 3000) {
+
+               if ((child = find_named_node (node, "RouteGroups")) == 0) {
+                       error << _("Session: XML state has no route groups section") << endmsg;
+                       goto out;
+               } else if (load_route_groups (*child, version)) {
+                       goto out;
+               }
+
+       } else if (version < 3000) {
+
+               if ((child = find_named_node (node, "EditGroups")) == 0) {
+                       error << _("Session: XML state has no edit groups section") << endmsg;
+                       goto out;
+               } else if (load_route_groups (*child, version)) {
+                       goto out;
+               }
+
+               if ((child = find_named_node (node, "MixGroups")) == 0) {
+                       error << _("Session: XML state has no mix groups section") << endmsg;
+                       goto out;
+               } else if (load_route_groups (*child, version)) {
+                       goto out;
+               }
        }
 
        if ((child = find_named_node (node, "Click")) == 0) {
                warning << _("Session: XML state has no click section") << endmsg;
        } else if (_click_io) {
-               _click_io->set_state (*child);
+               _click_io->set_state (*child, version);
        }
 
        if ((child = find_named_node (node, "ControlProtocols")) != 0) {
@@ -1325,7 +1435,7 @@ Session::set_state (const XMLNode& node)
 }
 
 int
-Session::load_routes (const XMLNode& node)
+Session::load_routes (const XMLNode& node, int version)
 {
        XMLNodeList nlist;
        XMLNodeConstIterator niter;
@@ -1337,7 +1447,12 @@ Session::load_routes (const XMLNode& node)
 
        for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
 
-               boost::shared_ptr<Route> route (XMLRouteFactory (**niter));
+               boost::shared_ptr<Route> route;
+               if (version < 3000) {
+                       route = XMLRouteFactory_2X (**niter, version);
+               } else {
+                       route = XMLRouteFactory (**niter, version);
+               }
 
                if (route == 0) {
                        error << _("Session: cannot create Route from XML description.") << endmsg;
@@ -1349,41 +1464,138 @@ Session::load_routes (const XMLNode& node)
                new_routes.push_back (route);
        }
 
-       add_routes (new_routes, false);
+       add_routes (new_routes, false, false);
 
        return 0;
 }
 
 boost::shared_ptr<Route>
-Session::XMLRouteFactory (const XMLNode& node)
+Session::XMLRouteFactory (const XMLNode& node, int version)
 {
+       boost::shared_ptr<Route> ret;
+
        if (node.name() != "Route") {
-               return boost::shared_ptr<Route> ((Route*) 0);
+               return ret;
        }
 
-       bool has_diskstream = (node.property ("diskstream") != 0 || node.property ("diskstream-id") != 0);
-       
+       XMLNode* ds_child = find_named_node (node, X_("Diskstream"));
+
        DataType type = DataType::AUDIO;
        const XMLProperty* prop = node.property("default-type");
 
        if (prop) {
-               type = DataType(prop->value());
-       } 
-       
-       assert(type != DataType::NIL);
+               type = DataType (prop->value());
+       }
+
+       assert (type != DataType::NIL);
+
+       if (ds_child) {
+
+               boost::shared_ptr<Track> track;
+
+                if (type == DataType::AUDIO) {
+                        track.reset (new AudioTrack (*this, X_("toBeResetFroXML")));
+                } else {
+                        track.reset (new MidiTrack (*this, X_("toBeResetFroXML")));
+                }
+
+                if (track->init()) {
+                        return ret;
+                }
+
+                if (track->set_state (node, version)) {
+                        return ret;
+                }
+
+#ifdef BOOST_SP_ENABLE_DEBUG_HOOKS
+                // boost_debug_shared_ptr_mark_interesting (track.get(), "Track");
+#endif
+                ret = track;
 
-       if (has_diskstream) {
-               if (type == DataType::AUDIO) {
-                       boost::shared_ptr<Route> ret (new AudioTrack (*this, node));
-                       return ret;
-               } else {
-                       boost::shared_ptr<Route> ret (new MidiTrack (*this, node));
-                       return ret;
-               }
        } else {
-               boost::shared_ptr<Route> ret (new Route (*this, node));
+               boost::shared_ptr<Route> r (new Route (*this, X_("toBeResetFroXML")));
+
+                if (r->init () == 0 && r->set_state (node, version) == 0) {
+#ifdef BOOST_SP_ENABLE_DEBUG_HOOKS
+                        // boost_debug_shared_ptr_mark_interesting (r.get(), "Route");
+#endif
+                        ret = r;
+                }
+       }
+
+       return ret;
+}
+
+boost::shared_ptr<Route>
+Session::XMLRouteFactory_2X (const XMLNode& node, int version)
+{
+       boost::shared_ptr<Route> ret;
+
+       if (node.name() != "Route") {
                return ret;
        }
+
+       XMLProperty const * ds_prop = node.property (X_("diskstream-id"));
+       if (!ds_prop) {
+               ds_prop = node.property (X_("diskstream"));
+       }
+
+       DataType type = DataType::AUDIO;
+       const XMLProperty* prop = node.property("default-type");
+
+       if (prop) {
+               type = DataType (prop->value());
+       }
+
+       assert (type != DataType::NIL);
+
+       if (ds_prop) {
+
+               list<boost::shared_ptr<Diskstream> >::iterator i = _diskstreams_2X.begin ();
+               while (i != _diskstreams_2X.end() && (*i)->id() != ds_prop->value()) {
+                       ++i;
+               }
+
+               if (i == _diskstreams_2X.end()) {
+                       error << _("Could not find diskstream for route") << endmsg;
+                       return boost::shared_ptr<Route> ();
+               }
+
+               boost::shared_ptr<Track> track;
+
+                if (type == DataType::AUDIO) {
+                        track.reset (new AudioTrack (*this, X_("toBeResetFroXML")));
+                } else {
+                        track.reset (new MidiTrack (*this, X_("toBeResetFroXML")));
+                }
+
+                if (track->init()) {
+                        return ret;
+                }
+
+                if (track->set_state (node, version)) {
+                        return ret;
+                }
+
+               track->set_diskstream (*i);
+
+#ifdef BOOST_SP_ENABLE_DEBUG_HOOKS
+                // boost_debug_shared_ptr_mark_interesting (track.get(), "Track");
+#endif
+                ret = track;
+
+       } else {
+               boost::shared_ptr<Route> r (new Route (*this, X_("toBeResetFroXML")));
+
+                if (r->init () == 0 && r->set_state (node, version) == 0) {
+#ifdef BOOST_SP_ENABLE_DEBUG_HOOKS
+                        // boost_debug_shared_ptr_mark_interesting (r.get(), "Route");
+#endif
+                        ret = r;
+                }
+       }
+
+       return ret;
 }
 
 int
@@ -1413,23 +1625,101 @@ Session::load_regions (const XMLNode& node)
        return 0;
 }
 
+int
+Session::load_compounds (const XMLNode& node)
+{
+       XMLNodeList calist = node.children();
+       XMLNodeConstIterator caiter;
+       XMLProperty *caprop;
+
+       for (caiter = calist.begin(); caiter != calist.end(); ++caiter) {
+               XMLNode* ca = *caiter;
+               ID orig_id;
+               ID copy_id;
+
+               if ((caprop = ca->property (X_("original"))) == 0) {
+                       continue;
+               }
+               orig_id = caprop->value();
+
+               if ((caprop = ca->property (X_("copy"))) == 0) {
+                       continue;
+               }
+               copy_id = caprop->value();
+
+               boost::shared_ptr<Region> orig = RegionFactory::region_by_id (orig_id);
+               boost::shared_ptr<Region> copy = RegionFactory::region_by_id (copy_id);
+
+               if (!orig || !copy) {
+                       warning << string_compose (_("Regions in compound description not found (ID's %1 and %2): ignored"),
+                                                  orig_id, copy_id)
+                               << endmsg;
+                       continue;
+               }
+
+               RegionFactory::add_compound_association (orig, copy);
+       }
+
+       return 0;
+}
+
+void
+Session::load_nested_sources (const XMLNode& node)
+{
+       XMLNodeList nlist;
+       XMLNodeConstIterator niter;
+
+       nlist = node.children();
+
+       for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
+               if ((*niter)->name() == "Source") {
+
+                       /* it may already exist, so don't recreate it unnecessarily 
+                        */
+
+                       XMLProperty* prop = (*niter)->property (X_("id"));
+                       if (!prop) {
+                               error << _("Nested source has no ID info in session state file! (ignored)") << endmsg;
+                               continue;
+                       }
+
+                       ID source_id (prop->value());
+
+                       if (!source_by_id (source_id)) {
+
+                               try {
+                                       SourceFactory::create (*this, **niter, true);
+                               }
+                               catch (failed_constructor& err) {
+                                       error << string_compose (_("Cannot reconstruct nested source for region %1"), name()) << endmsg;
+                               }
+                       }
+               }
+       }
+}
+
 boost::shared_ptr<Region>
 Session::XMLRegionFactory (const XMLNode& node, bool full)
 {
        const XMLProperty* type = node.property("type");
 
        try {
-       
-       if ( !type || type->value() == "audio" ) {
 
-               return boost::shared_ptr<Region>(XMLAudioRegionFactory (node, full));
-       
-       } else if (type->value() == "midi") {
-               
-               return boost::shared_ptr<Region>(XMLMidiRegionFactory (node, full));
+               const XMLNodeList& nlist = node.children();
+
+               for (XMLNodeConstIterator niter = nlist.begin(); niter != nlist.end(); ++niter) {
+                       XMLNode *child = (*niter);
+                       if (child->name() == "NestedSource") {
+                               load_nested_sources (*child);
+                       }
+               }
+
+                if (!type || type->value() == "audio") {
+                        return boost::shared_ptr<Region>(XMLAudioRegionFactory (node, full));
+                } else if (type->value() == "midi") {
+                        return boost::shared_ptr<Region>(XMLMidiRegionFactory (node, full));
+                }
 
-       }
-       
        } catch (failed_constructor& err) {
                return boost::shared_ptr<Region> ();
        }
@@ -1438,7 +1728,7 @@ Session::XMLRegionFactory (const XMLNode& node, bool full)
 }
 
 boost::shared_ptr<AudioRegion>
-Session::XMLAudioRegionFactory (const XMLNode& node, bool full)
+Session::XMLAudioRegionFactory (const XMLNode& node, bool /*full*/)
 {
        const XMLProperty* prop;
        boost::shared_ptr<Source> source;
@@ -1447,7 +1737,7 @@ Session::XMLAudioRegionFactory (const XMLNode& node, bool full)
        SourceList master_sources;
        uint32_t nchans = 1;
        char buf[128];
-       
+
        if (node.name() != X_("Region")) {
                return boost::shared_ptr<AudioRegion>();
        }
@@ -1460,7 +1750,7 @@ Session::XMLAudioRegionFactory (const XMLNode& node, bool full)
                cerr << "no name for this region\n";
                abort ();
        }
-       
+
        if ((prop = node.property (X_("source-0"))) == 0) {
                if ((prop = node.property ("source")) == 0) {
                        error << _("Session: XMLNode describing a AudioRegion is incomplete (no source)") << endmsg;
@@ -1474,7 +1764,7 @@ Session::XMLAudioRegionFactory (const XMLNode& node, bool full)
                error << string_compose(_("Session: XMLNode describing a AudioRegion references an unknown source id =%1"), s_id) << endmsg;
                return boost::shared_ptr<AudioRegion>();
        }
-       
+
        as = boost::dynamic_pointer_cast<AudioSource>(source);
        if (!as) {
                error << string_compose(_("Session: XMLNode describing a AudioRegion references a non-audio source id =%1"), s_id) << endmsg;
@@ -1488,14 +1778,14 @@ Session::XMLAudioRegionFactory (const XMLNode& node, bool full)
        for (uint32_t n=1; n < nchans; ++n) {
                snprintf (buf, sizeof(buf), X_("source-%d"), n);
                if ((prop = node.property (buf)) != 0) {
-                       
+
                        PBD::ID id2 (prop->value());
-                       
+
                        if ((source = source_by_id (id2)) == 0) {
                                error << string_compose(_("Session: XMLNode describing a AudioRegion references an unknown source id =%1"), id2) << endmsg;
                                return boost::shared_ptr<AudioRegion>();
                        }
-                       
+
                        as = boost::dynamic_pointer_cast<AudioSource>(source);
                        if (!as) {
                                error << string_compose(_("Session: XMLNode describing a AudioRegion references a non-audio source id =%1"), id2) << endmsg;
@@ -1508,14 +1798,14 @@ Session::XMLAudioRegionFactory (const XMLNode& node, bool full)
        for (uint32_t n = 0; n < nchans; ++n) {
                snprintf (buf, sizeof(buf), X_("master-source-%d"), n);
                if ((prop = node.property (buf)) != 0) {
-                       
+
                        PBD::ID id2 (prop->value());
-                       
+
                        if ((source = source_by_id (id2)) == 0) {
                                error << string_compose(_("Session: XMLNode describing a AudioRegion references an unknown source id =%1"), id2) << endmsg;
                                return boost::shared_ptr<AudioRegion>();
                        }
-                       
+
                        as = boost::dynamic_pointer_cast<AudioSource>(source);
                        if (!as) {
                                error << string_compose(_("Session: XMLNode describing a AudioRegion references a non-audio source id =%1"), id2) << endmsg;
@@ -1548,7 +1838,7 @@ Session::XMLAudioRegionFactory (const XMLNode& node, bool full)
                }
 
                return region;
-                                                      
+
        }
 
        catch (failed_constructor& err) {
@@ -1557,30 +1847,22 @@ Session::XMLAudioRegionFactory (const XMLNode& node, bool full)
 }
 
 boost::shared_ptr<MidiRegion>
-Session::XMLMidiRegionFactory (const XMLNode& node, bool full)
+Session::XMLMidiRegionFactory (const XMLNode& node, bool /*full*/)
 {
        const XMLProperty* prop;
        boost::shared_ptr<Source> source;
        boost::shared_ptr<MidiSource> ms;
        SourceList sources;
-       uint32_t nchans = 1;
-       
+
        if (node.name() != X_("Region")) {
                return boost::shared_ptr<MidiRegion>();
        }
 
-       if ((prop = node.property (X_("channels"))) != 0) {
-               nchans = atoi (prop->value().c_str());
-       }
-       
        if ((prop = node.property ("name")) == 0) {
                cerr << "no name for this region\n";
                abort ();
        }
 
-       // Multiple midi channels?  that's just crazy talk
-       assert(nchans == 1);
-
        if ((prop = node.property (X_("source-0"))) == 0) {
                if ((prop = node.property ("source")) == 0) {
                        error << _("Session: XMLNode describing a MidiRegion is incomplete (no source)") << endmsg;
@@ -1647,11 +1929,11 @@ Session::path_from_region_name (DataType type, string name, string identifier)
        sys::path source_dir = ((type == DataType::AUDIO)
                ? sdir.sound_path() : sdir.midi_path());
 
-       string ext = ((type == DataType::AUDIO) ? ".wav" : ".mid");
+        string ext = native_header_format_extension (config.get_native_file_header_format(), type);
 
        for (n = 0; n < 999999; ++n) {
                if (identifier.length()) {
-                       snprintf (buf, sizeof(buf), "%s%s%" PRIu32 "%s", name.c_str(), 
+                       snprintf (buf, sizeof(buf), "%s%s%" PRIu32 "%s", name.c_str(),
                                  identifier.c_str(), n, ext.c_str());
                } else {
                        snprintf (buf, sizeof(buf), "%s-%" PRIu32 "%s", name.c_str(),
@@ -1671,7 +1953,7 @@ Session::path_from_region_name (DataType type, string name, string identifier)
 
        return "";
 }
-       
+
 
 int
 Session::load_sources (const XMLNode& node)
@@ -1685,13 +1967,47 @@ Session::load_sources (const XMLNode& node)
        set_dirty();
 
        for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
+          retry:
                try {
                        if ((source = XMLSourceFactory (**niter)) == 0) {
                                error << _("Session: cannot create Source from XML description.") << endmsg;
                        }
+
                } catch (MissingSource& err) {
-                       warning << _("A sound file is missing. It will be replaced by silence.") << endmsg;
-                       source = SourceFactory::createSilent (*this, **niter, max_frames, _current_frame_rate);
+
+                        int user_choice;
+
+                        if (!no_questions_about_missing_files) {
+                                user_choice = MissingFile (this, err.path, err.type).get_value_or (-1);
+                        } else {
+                                user_choice = -2;
+                        }
+
+                        switch (user_choice) {
+                        case 0:
+                                /* user added a new search location, so try again */
+                                goto retry;
+
+
+                        case 1:
+                                /* user asked to quit the entire session load
+                                 */
+                                return -1;
+
+                        case 2:
+                                no_questions_about_missing_files = true;
+                                goto retry;
+
+                        case 3:
+                                no_questions_about_missing_files = true;
+                                /* fallthru */
+
+                        case -1:
+                        default:
+                                warning << _("A sound file is missing. It will be replaced by silence.") << endmsg;
+                                source = SourceFactory::createSilent (*this, **niter, max_framecnt, _current_frame_rate);
+                                break;
+                        }
                }
        }
 
@@ -1711,7 +2027,7 @@ Session::XMLSourceFactory (const XMLNode& node)
        }
 
        catch (failed_constructor& err) {
-               error << _("Found a sound file that cannot be used by Ardour. Talk to the progammers.") << endmsg;
+               error << string_compose (_("Found a sound file that cannot be used by %1. Talk to the progammers."), PROGRAM_NAME) << endmsg;
                return boost::shared_ptr<Source>();
        }
 }
@@ -1733,66 +2049,43 @@ Session::save_template (string template_name)
        }
        catch(sys::filesystem_error& ex)
        {
-               error << string_compose(_("Could not create mix templates directory \"%1\" (%2)"),
+               error << string_compose(_("Could not create templates directory \"%1\" (%2)"),
                                user_template_dir.to_string(), ex.what()) << endmsg;
                return -1;
        }
 
        tree.set_root (&get_template());
 
-       sys::path template_file_path(user_template_dir);
-       template_file_path /= template_name + template_suffix;
-
-       if (sys::exists (template_file_path))
+       sys::path template_dir_path(user_template_dir);
+       
+       /* directory to put the template in */
+       template_dir_path /= template_name;
+       if (sys::exists (template_dir_path))
        {
                warning << string_compose(_("Template \"%1\" already exists - new version not created"),
-                               template_file_path.to_string()) << endmsg;
-               return -1;
-       }
-
-       if (!tree.write (template_file_path.to_string())) {
-               error << _("mix template not saved") << endmsg;
+                               template_dir_path.to_string()) << endmsg;
                return -1;
        }
+       
+       sys::create_directories (template_dir_path);
 
-       return 0;
-}
-
-int
-Session::rename_template (string old_name, string new_name) 
-{
-       sys::path old_path (user_template_directory());
-       old_path /= old_name + template_suffix;
-
-       sys::path new_path(user_template_directory());
-       new_path /= new_name + template_suffix;
+       /* file to write */
+       sys::path template_file_path = template_dir_path;
+       template_file_path /= template_name + template_suffix;
 
-       if (sys::exists (new_path)) {
-               warning << string_compose(_("Template \"%1\" already exists - template not renamed"),
-                                         new_path.to_string()) << endmsg;
+       if (!tree.write (template_file_path.to_string())) {
+               error << _("template not saved") << endmsg;
                return -1;
        }
 
-       try {
-               sys::rename (old_path, new_path);
-               return 0;
-       } catch (...) {
-               return -1;
-       }
-}
+       /* copy plugin state directory */
 
-int
-Session::delete_template (string name) 
-{
-       sys::path path = user_template_directory();
-       path /= name + template_suffix;
+       sys::path template_plugin_state_path = template_dir_path;
+       template_plugin_state_path /= X_("plugins");
+       sys::create_directories (template_plugin_state_path);
+       sys::copy_files (plugins_dir(), template_plugin_state_path);
 
-       try {
-               sys::remove (path);
-               return 0;
-       } catch (...) {
-               return -1;
-       }
+       return 0;
 }
 
 void
@@ -1807,7 +2100,7 @@ Session::refresh_disk_space ()
        /* get freespace on every FS that is part of the session path */
 
        _total_free_4k_blocks = 0;
-       
+
        for (i = session_dirs.begin(); i != session_dirs.end(); ++i) {
                statfs ((*i).path.c_str(), &statfsbuf);
 
@@ -1832,8 +2125,8 @@ Session::get_best_session_directory_for_new_source ()
        }
 
        /* OK, here's the algorithm we're following here:
-          
-       We want to select which directory to use for 
+
+       We want to select which directory to use for
        the next file source to be created. Ideally,
        we'd like to use a round-robin process so as to
        get maximum performance benefits from splitting
@@ -1852,15 +2145,15 @@ Session::get_best_session_directory_for_new_source ()
 
        So, we use a user-configurable space threshold. If
        there are at least 2 filesystems with more than this
-       much space available, we use RR selection between them. 
+       much space available, we use RR selection between them.
        If not, then we pick the filesystem with the most space.
 
        This gets a good balance between the two
-       approaches.  
+       approaches.
        */
-       
+
        refresh_disk_space ();
-       
+
        int free_enough = 0;
 
        for (i = session_dirs.begin(); i != session_dirs.end(); ++i) {
@@ -1896,13 +2189,13 @@ Session::get_best_session_directory_for_new_source ()
                /* pick FS with the most freespace (and that
                   seems to actually work ...)
                */
-               
+
                vector<space_and_path> sorted;
                space_and_path_ascending_cmp cmp;
 
                sorted = session_dirs;
                sort (sorted.begin(), sorted.end(), cmp);
-               
+
                for (i = sorted.begin(); i != sorted.end(); ++i) {
                        if (create_session_directory ((*i).path)) {
                                result = (*i).path;
@@ -1916,87 +2209,28 @@ Session::get_best_session_directory_for_new_source ()
 }
 
 int
-Session::load_playlists (const XMLNode& node)
+Session::load_named_selections (const XMLNode& node)
 {
        XMLNodeList nlist;
        XMLNodeConstIterator niter;
-       boost::shared_ptr<Playlist> playlist;
+       NamedSelection *ns;
 
        nlist = node.children();
 
        set_dirty();
 
        for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
-               
-               if ((playlist = XMLPlaylistFactory (**niter)) == 0) {
-                       error << _("Session: cannot create Playlist from XML description.") << endmsg;
+
+               if ((ns = XMLNamedSelectionFactory (**niter)) == 0) {
+                       error << _("Session: cannot create Named Selection from XML description.") << endmsg;
                }
        }
 
        return 0;
 }
 
-int
-Session::load_unused_playlists (const XMLNode& node)
-{
-       XMLNodeList nlist;
-       XMLNodeConstIterator niter;
-       boost::shared_ptr<Playlist> playlist;
-
-       nlist = node.children();
-
-       set_dirty();
-
-       for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
-               
-               if ((playlist = XMLPlaylistFactory (**niter)) == 0) {
-                       error << _("Session: cannot create Playlist from XML description.") << endmsg;
-                       continue;
-               }
-
-               // now manually untrack it
-
-               track_playlist (false, boost::weak_ptr<Playlist> (playlist));
-       }
-
-       return 0;
-}
-
-boost::shared_ptr<Playlist>
-Session::XMLPlaylistFactory (const XMLNode& node)
-{
-       try {
-               return PlaylistFactory::create (*this, node);
-       }
-
-       catch (failed_constructor& err) {
-               return boost::shared_ptr<Playlist>();
-       }
-}
-
-int
-Session::load_named_selections (const XMLNode& node)
-{
-       XMLNodeList nlist;
-       XMLNodeConstIterator niter;
-       NamedSelection *ns;
-
-       nlist = node.children();
-
-       set_dirty();
-
-       for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
-               
-               if ((ns = XMLNamedSelectionFactory (**niter)) == 0) {
-                       error << _("Session: cannot create Named Selection from XML description.") << endmsg;
-               }
-       }
-
-       return 0;
-}
-
-NamedSelection *
-Session::XMLNamedSelectionFactory (const XMLNode& node)
+NamedSelection *
+Session::XMLNamedSelectionFactory (const XMLNode& node)
 {
        try {
                return new NamedSelection (*this, node);
@@ -2019,63 +2253,65 @@ Session::analysis_dir () const
        return Glib::build_filename (_path, "analysis");
 }
 
+string
+Session::plugins_dir () const
+{
+       return Glib::build_filename (_path, "plugins");
+}
+
 int
 Session::load_bundles (XMLNode const & node)
 {
-       XMLNodeList nlist = node.children();
-       XMLNodeConstIterator niter;
+       XMLNodeList nlist = node.children();
+       XMLNodeConstIterator niter;
 
-       set_dirty();
+       set_dirty();
 
-       for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
-               if ((*niter)->name() == "InputBundle") {
+       for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
+               if ((*niter)->name() == "InputBundle") {
                        add_bundle (boost::shared_ptr<UserBundle> (new UserBundle (**niter, true)));
-               } else if ((*niter)->name() == "OutputBundle") {
-                       add_bundle (boost::shared_ptr<UserBundle> (new UserBundle (**niter, false)));
-               } else {
-                       error << string_compose(_("Unknown node \"%1\" found in Bundles list from state file"), (*niter)->name()) << endmsg;
-                       return -1;
-               }
-       }
+               } else if ((*niter)->name() == "OutputBundle") {
+                       add_bundle (boost::shared_ptr<UserBundle> (new UserBundle (**niter, false)));
+               } else {
+                       error << string_compose(_("Unknown node \"%1\" found in Bundles list from state file"), (*niter)->name()) << endmsg;
+                       return -1;
+               }
+       }
 
        return 0;
-}                              
-
-int
-Session::load_edit_groups (const XMLNode& node)
-{
-       return load_route_groups (node, true);
-}
-
-int
-Session::load_mix_groups (const XMLNode& node)
-{
-       return load_route_groups (node, false);
 }
 
 int
-Session::load_route_groups (const XMLNode& node, bool edit)
+Session::load_route_groups (const XMLNode& node, int version)
 {
        XMLNodeList nlist = node.children();
        XMLNodeConstIterator niter;
 
-       set_dirty();
+       set_dirty ();
 
-       for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
-               if ((*niter)->name() == "RouteGroup") {
-                       RouteGroup* rg = new RouteGroup (*this, "");
-                       if (edit) {
-                               add_edit_group (rg);
-                               rg->set_state (**niter);
-                       } else {
-                               add_mix_group (rg);
-                               rg->set_state (**niter);
+       if (version >= 3000) {
+
+               for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
+                       if ((*niter)->name() == "RouteGroup") {
+                               RouteGroup* rg = new RouteGroup (*this, "");
+                               add_route_group (rg);
+                               rg->set_state (**niter, version);
+                       }
+               }
+
+       } else if (version < 3000) {
+
+               for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
+                       if ((*niter)->name() == "EditGroup" || (*niter)->name() == "MixGroup") {
+                               RouteGroup* rg = new RouteGroup (*this, "");
+                               add_route_group (rg);
+                               rg->set_state (**niter, version);
                        }
                }
        }
-       
+
        return 0;
-}                              
+}
 
 void
 Session::auto_save()
@@ -2084,7 +2320,7 @@ Session::auto_save()
 }
 
 static bool
-state_file_filter (const string &str, void *arg)
+state_file_filter (const string &str, void */*arg*/)
 {
        return (str.length() > strlen(statefile_suffix) &&
                str.find (statefile_suffix) == (str.length() - strlen (statefile_suffix)));
@@ -2100,12 +2336,12 @@ static string*
 remove_end(string* state)
 {
        string statename(*state);
-       
+
        string::size_type start,end;
-       if ((start = statename.find_last_of ('/')) != string::npos) {
+       if ((start = statename.find_last_of (G_DIR_SEPARATOR)) != string::npos) {
                statename = statename.substr (start+1);
        }
-               
+
        if ((end = statename.rfind(".ardour")) == string::npos) {
                end = statename.length();
        }
@@ -2114,16 +2350,16 @@ remove_end(string* state)
 }
 
 vector<string *> *
-Session::possible_states (string path) 
+Session::possible_states (string path)
 {
        PathScanner scanner;
        vector<string*>* states = scanner (path, state_file_filter, 0, false, false);
-       
+
        transform(states->begin(), states->end(), states->begin(), remove_end);
-       
+
        string_cmp cmp;
        sort (states->begin(), states->end(), cmp);
-       
+
        return states;
 }
 
@@ -2134,68 +2370,50 @@ Session::possible_states () const
 }
 
 void
-Session::add_edit_group (RouteGroup* g)
+Session::add_route_group (RouteGroup* g)
 {
-       edit_groups.push_back (g);
-       edit_group_added (g); /* EMIT SIGNAL */
-       set_dirty ();
-}
+       _route_groups.push_back (g);
+       route_group_added (g); /* EMIT SIGNAL */
+
+       g->RouteAdded.connect_same_thread (*this, boost::bind (&Session::route_added_to_route_group, this, _1, _2));
+       g->RouteRemoved.connect_same_thread (*this, boost::bind (&Session::route_removed_from_route_group, this, _1, _2));
+       g->PropertyChanged.connect_same_thread (*this, boost::bind (&Session::route_group_property_changed, this, g));
 
-void
-Session::add_mix_group (RouteGroup* g)
-{
-       mix_groups.push_back (g);
-       mix_group_added (g); /* EMIT SIGNAL */
        set_dirty ();
 }
 
 void
-Session::remove_edit_group (RouteGroup& rg)
+Session::remove_route_group (RouteGroup& rg)
 {
        list<RouteGroup*>::iterator i;
 
-       if ((i = find (edit_groups.begin(), edit_groups.end(), &rg)) != edit_groups.end()) {
-               (*i)->apply (&Route::drop_edit_group, this);
-               edit_groups.erase (i);
-               edit_group_removed (); /* EMIT SIGNAL */
-       }
+       if ((i = find (_route_groups.begin(), _route_groups.end(), &rg)) != _route_groups.end()) {
+               _route_groups.erase (i);
+               delete &rg;
 
-       delete &rg;
+               route_group_removed (); /* EMIT SIGNAL */
+       }
 }
 
+/** Set a new order for our route groups, without adding or removing any.
+ *  @param groups Route group list in the new order.
+ */
 void
-Session::remove_mix_group (RouteGroup& rg)
+Session::reorder_route_groups (list<RouteGroup*> groups)
 {
-       list<RouteGroup*>::iterator i;
-
-       if ((i = find (mix_groups.begin(), mix_groups.end(), &rg)) != mix_groups.end()) {
-               (*i)->apply (&Route::drop_mix_group, this);
-               mix_groups.erase (i);
-               mix_group_removed (); /* EMIT SIGNAL */
-       }
+       _route_groups = groups;
 
-       delete &rg;
+       route_groups_reordered (); /* EMIT SIGNAL */
+       set_dirty ();
 }
 
-RouteGroup *
-Session::mix_group_by_name (string name)
-{
-       list<RouteGroup *>::iterator i;
-
-       for (i = mix_groups.begin(); i != mix_groups.end(); ++i) {
-               if ((*i)->name() == name) {
-                       return* i;
-               }
-       }
-       return 0;
-}
 
 RouteGroup *
-Session::edit_group_by_name (string name)
+Session::route_group_by_name (string name)
 {
        list<RouteGroup *>::iterator i;
 
-       for (i = edit_groups.begin(); i != edit_groups.end(); ++i) {
+       for (i = _route_groups.begin(); i != _route_groups.end(); ++i) {
                if ((*i)->name() == name) {
                        return* i;
                }
@@ -2203,138 +2421,118 @@ Session::edit_group_by_name (string name)
        return 0;
 }
 
-void
-Session::begin_reversible_command(const string& name)
+RouteGroup&
+Session::all_route_group() const
 {
-       UndoTransaction* trans = new UndoTransaction();
-       trans->set_name(name);
-       if (!_current_trans.empty()) {
-               _current_trans.top()->add_command(trans);
-       }
-       _current_trans.push(trans);
+        return *_all_route_group;
 }
 
 void
-Session::commit_reversible_command(Command *cmd)
+Session::add_commands (vector<Command*> const & cmds)
 {
-       assert(!_current_trans.empty());
-       struct timeval now;
-
-       if (cmd) {
-               _current_trans.top()->add_command(cmd);
+       for (vector<Command*>::const_iterator i = cmds.begin(); i != cmds.end(); ++i) {
+               add_command (*i);
        }
-
-       if (_current_trans.top()->empty()) {
-               _current_trans.pop();
-               return;
-       }
-
-       gettimeofday(&now, 0);
-       _current_trans.top()->set_timestamp(now);
-
-       _history.add(_current_trans.top());
-       _current_trans.pop();
 }
 
-Session::GlobalRouteBooleanState 
-Session::get_global_route_boolean (bool (Route::*method)(void) const)
+void
+Session::begin_reversible_command (const string& name)
 {
-       GlobalRouteBooleanState s;
-       boost::shared_ptr<RouteList> r = routes.reader ();
-
-       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               if (!(*i)->is_hidden()) {
-                       RouteBooleanState v;
-                       
-                       v.first =* i;
-                       Route* r = (*i).get();
-                       v.second = (r->*method)();
-                       
-                       s.push_back (v);
-               }
-       }
-
-       return s;
+       begin_reversible_command (g_quark_from_string (name.c_str ()));
 }
 
-Session::GlobalRouteMeterState
-Session::get_global_route_metering ()
+/** Begin a reversible command using a GQuark to identify it.
+ *  begin_reversible_command() and commit_reversible_command() calls may be nested,
+ *  but there must be as many begin...()s as there are commit...()s.
+ */
+void
+Session::begin_reversible_command (GQuark q)
 {
-       GlobalRouteMeterState s;
-       boost::shared_ptr<RouteList> r = routes.reader ();
+       /* If nested begin/commit pairs are used, we create just one UndoTransaction
+          to hold all the commands that are committed.  This keeps the order of
+          commands correct in the history.
+       */
 
-       for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-               if (!(*i)->is_hidden()) {
-                       RouteMeterState v;
-                       
-                       v.first =* i;
-                       v.second = (*i)->meter_point();
-                       
-                       s.push_back (v);
-               }
+       if (_current_trans == 0) {
+               /* start a new transaction */
+               assert (_current_trans_quarks.empty ());
+               _current_trans = new UndoTransaction();
+               _current_trans->set_name (g_quark_to_string (q));
        }
 
-       return s;
+       _current_trans_quarks.push_front (q);
 }
 
 void
-Session::set_global_route_metering (GlobalRouteMeterState s, void* arg) 
+Session::commit_reversible_command (Command *cmd)
 {
-       for (GlobalRouteMeterState::iterator i = s.begin(); i != s.end(); ++i) {
+       assert (_current_trans);
+       assert (!_current_trans_quarks.empty ());
 
-               boost::shared_ptr<Route> r = (i->first.lock());
+       struct timeval now;
 
-               if (r) {
-                       r->set_meter_point (i->second, arg);
-               }
+       if (cmd) {
+               _current_trans->add_command (cmd);
        }
-}
 
-void
-Session::set_global_route_boolean (GlobalRouteBooleanState s, void (Route::*method)(bool, void*), void* arg)
-{
-       for (GlobalRouteBooleanState::iterator i = s.begin(); i != s.end(); ++i) {
+       _current_trans_quarks.pop_front ();
 
-               boost::shared_ptr<Route> r = (i->first.lock());
+       if (!_current_trans_quarks.empty ()) {
+               /* the transaction we're committing is not the top-level one */
+               return;
+       }
 
-               if (r) {
-                       Route* rp = r.get();
-                       (rp->*method) (i->second, arg);
-               }
+       if (_current_trans->empty()) {
+               /* no commands were added to the transaction, so just get rid of it */
+               delete _current_trans;
+               _current_trans = 0;
+               return;
        }
-}
 
-void
-Session::set_global_mute (GlobalRouteBooleanState s, void* src)
-{
-       set_global_route_boolean (s, &Route::set_mute, src);
-}
+       gettimeofday (&now, 0);
+       _current_trans->set_timestamp (now);
 
-void
-Session::set_global_solo (GlobalRouteBooleanState s, void* src)
-{
-       set_global_route_boolean (s, &Route::set_solo, src);
+       _history.add (_current_trans);
+       _current_trans = 0;
 }
 
-void
-Session::set_global_record_enable (GlobalRouteBooleanState s, void* src)
+static bool
+accept_all_audio_files (const string& path, void */*arg*/)
 {
-       set_global_route_boolean (s, &Route::set_record_enable, src);
+        if (!Glib::file_test (path, Glib::FILE_TEST_IS_REGULAR)) {
+                return false;
+        }
+
+        if (!AudioFileSource::safe_audio_file_extension (path)) {
+                return false;
+        }
+
+        return true;
 }
 
 static bool
-accept_all_non_peak_files (const string& path, void *arg)
+accept_all_midi_files (const string& path, void */*arg*/)
 {
-       return (path.length() > 5 && path.find (peakfile_suffix) != (path.length() - 5));
+        if (!Glib::file_test (path, Glib::FILE_TEST_IS_REGULAR)) {
+                return false;
+        }
+
+       return ((path.length() > 4 && path.find (".mid") != (path.length() - 4)) ||
+                (path.length() > 4 && path.find (".smf") != (path.length() - 4)) ||
+                (path.length() > 5 && path.find (".midi") != (path.length() - 5)));
 }
 
 static bool
-accept_all_state_files (const string& path, void *arg)
+accept_all_state_files (const string& path, void */*arg*/)
 {
+        if (!Glib::file_test (path, Glib::FILE_TEST_IS_REGULAR)) {
+                return false;
+        }
+
        return (path.length() > 7 && path.find (".ardour") == (path.length() - 7));
 }
 
-int 
+int
 Session::find_all_sources (string path, set<string>& result)
 {
        XMLTree tree;
@@ -2356,23 +2554,31 @@ Session::find_all_sources (string path, set<string>& result)
        set_dirty();
 
        for (niter = nlist.begin(); niter != nlist.end(); ++niter) {
-               
+
                XMLProperty* prop;
 
+               if ((prop = (*niter)->property (X_("type"))) == 0) {
+                       continue;
+               }
+
+               DataType type (prop->value());
+
                if ((prop = (*niter)->property (X_("name"))) == 0) {
                        continue;
                }
 
-               if (prop->value()[0] == '/') {
+               if (Glib::path_is_absolute (prop->value())) {
                        /* external file, ignore */
                        continue;
                }
 
-               sys::path source_path = _session_dir->sound_path ();
-
-               source_path /= prop->value ();
+               string found_path;
+               bool is_new;
+               uint16_t chan;
 
-               result.insert (source_path.to_string ());
+               if (FileSource::find (*this, type, prop->value(), true, is_new, chan, found_path)) {
+                       result.insert (found_path);
+               }
        }
 
        return 0;
@@ -2390,19 +2596,19 @@ Session::find_all_sources_across_snapshots (set<string>& result, bool exclude_th
 
        ripped = _path;
 
-       if (ripped[ripped.length()-1] == '/') {
+       if (ripped[ripped.length()-1] == G_DIR_SEPARATOR) {
                ripped = ripped.substr (0, ripped.length() - 1);
        }
 
        state_files = scanner (ripped, accept_all_state_files, (void *) 0, false, true);
-       
+
        if (state_files == 0) {
                /* impossible! */
                return 0;
        }
 
        this_snapshot_path = _path;
-       this_snapshot_path += _current_snapshot_name;
+       this_snapshot_path += legalize_for_path (_current_snapshot_name);
        this_snapshot_path += statefile_suffix;
 
        for (vector<string*>::iterator i = state_files->begin(); i != state_files->end(); ++i) {
@@ -2424,69 +2630,77 @@ struct RegionCounter {
     AudioSourceList::iterator iter;
     boost::shared_ptr<Region> region;
     uint32_t count;
-    
+
     RegionCounter() : count (0) {}
 };
 
 int
-Session::cleanup_sources (Session::cleanup_report& rep)
+Session::ask_about_playlist_deletion (boost::shared_ptr<Playlist> p)
+{
+        boost::optional<int> r = AskAboutPlaylistDeletion (p);
+       return r.get_value_or (1);
+}
+
+void
+Session::cleanup_regions ()
+{
+       const RegionFactory::RegionMap& regions (RegionFactory::regions());
+
+       for (RegionFactory::RegionMap::const_iterator i = regions.begin(); i != regions.end(); ++i) {
+
+               uint32_t used = playlists->region_use_count (i->second);
+
+               if (used == 0 && !i->second->automatic ()) {
+                       RegionFactory::map_remove (i->second);
+               }
+       }
+
+       /* dump the history list */
+       _history.clear ();
+
+       save_state ("");
+}
+
+int
+Session::cleanup_sources (CleanupReport& rep)
 {
        // FIXME: needs adaptation to midi
-       
+
        vector<boost::shared_ptr<Source> > dead_sources;
-       vector<boost::shared_ptr<Playlist> > playlists_tbd;
        PathScanner scanner;
-       string sound_path;
+       string audio_path;
+       string midi_path;
        vector<space_and_path>::iterator i;
        vector<space_and_path>::iterator nexti;
-       vector<string*>* soundfiles;
+       vector<string*>* candidates;
+       vector<string*>* candidates2;
        vector<string> unused;
        set<string> all_sources;
        bool used;
        string spath;
        int ret = -1;
-               
-       _state_of_the_state = (StateOfTheState) (_state_of_the_state | InCleanup);
-
-       
-       /* step 1: consider deleting all unused playlists */
 
-       for (PlaylistList::iterator x = unused_playlists.begin(); x != unused_playlists.end(); ++x) {
-               int status;
-
-               status = AskAboutPlaylistDeletion (*x);
-
-               switch (status) {
-               case -1:
-                       ret = 0;
-                       goto out;
-                       break;
+       _state_of_the_state = (StateOfTheState) (_state_of_the_state | InCleanup);
 
-               case 0:
-                       playlists_tbd.push_back (*x);
-                       break;
+       /* consider deleting all unused playlists */
 
-               default:
-                       /* leave it alone */
-                       break;
-               }
+       if (playlists->maybe_delete_unused (boost::bind (Session::ask_about_playlist_deletion, _1))) {
+               ret = 0;
+               goto out;
        }
 
-       /* now delete any that were marked for deletion */
-
-       for (vector<boost::shared_ptr<Playlist> >::iterator x = playlists_tbd.begin(); x != playlists_tbd.end(); ++x) {
-               (*x)->drop_references ();
-       }
+        /* sync the "all regions" property of each playlist with its current state
+         */
 
-       playlists_tbd.clear ();
+        playlists->sync_all_regions_with_regions ();
 
-       /* step 2: find all un-used sources */
+       /* find all un-used sources */
 
        rep.paths.clear ();
        rep.space = 0;
 
        for (SourceMap::iterator i = sources.begin(); i != sources.end(); ) {
-               
+
                SourceMap::iterator tmp;
 
                tmp = i;
@@ -2496,15 +2710,15 @@ Session::cleanup_sources (Session::cleanup_report& rep)
                   capture files.
                */
 
-               if (!i->second->used() && i->second->length(i->second->timeline_position()) > 0) {
+               if (!i->second->used() && (i->second->length(i->second->timeline_position() > 0))) {
                        dead_sources.push_back (i->second);
-                       i->second->GoingAway();
-               } 
+                       i->second->drop_references ();
+               }
 
                i = tmp;
        }
 
-       /* build a list of all the possible sound directories for the session */
+       /* build a list of all the possible audio directories for the session */
 
        for (i = session_dirs.begin(); i != session_dirs.end(); ) {
 
@@ -2512,81 +2726,131 @@ Session::cleanup_sources (Session::cleanup_report& rep)
                ++nexti;
 
                SessionDirectory sdir ((*i).path);
-               sound_path += sdir.sound_path().to_string();
+               audio_path += sdir.sound_path().to_string();
 
                if (nexti != session_dirs.end()) {
-                       sound_path += ':';
+                       audio_path += ':';
                }
 
                i = nexti;
        }
 
-       /* now do the same thing for the files that ended up in the sounds dir(s) 
-          but are not referenced as sources in any snapshot.
-       */
 
-       soundfiles = scanner (sound_path, accept_all_non_peak_files, (void *) 0, false, true);
+       /* build a list of all the possible midi directories for the session */
 
-       if (soundfiles == 0) {
-               return 0;
+       for (i = session_dirs.begin(); i != session_dirs.end(); ) {
+
+               nexti = i;
+               ++nexti;
+
+               SessionDirectory sdir ((*i).path);
+               midi_path += sdir.midi_path().to_string();
+
+               if (nexti != session_dirs.end()) {
+                       midi_path += ':';
+               }
+
+               i = nexti;
        }
 
+       candidates = scanner (audio_path, accept_all_audio_files, (void *) 0, true, true);
+       candidates2 = scanner (midi_path, accept_all_midi_files, (void *) 0, true, true);
+
+        /* merge them */
+
+        if (candidates) {
+                if (candidates2) {
+                        for (vector<string*>::iterator i = candidates2->begin(); i != candidates2->end(); ++i) {
+                                candidates->push_back (*i);
+                        }
+                        delete candidates2;
+                }
+        } else {
+                candidates = candidates2; // might still be null
+        }
+
        /* find all sources, but don't use this snapshot because the
           state file on disk still references sources we may have already
           dropped.
        */
-       
+
        find_all_sources_across_snapshots (all_sources, true);
 
        /*  add our current source list
         */
-       
-       for (SourceMap::iterator i = sources.begin(); i != sources.end(); ++i) {
+
+       for (SourceMap::iterator i = sources.begin(); i != sources.end(); ) {
                boost::shared_ptr<FileSource> fs;
-               
+                SourceMap::iterator tmp = i;
+                ++tmp;
+
                if ((fs = boost::dynamic_pointer_cast<FileSource> (i->second)) != 0) {
-                       all_sources.insert (fs->path());
-               } 
+                        if (playlists->source_use_count (fs) != 0) {
+                                all_sources.insert (fs->path());
+                        } else {
+
+                                /* we might not remove this source from disk, because it may be used
+                                   by other snapshots, but its not being used in this version
+                                   so lets get rid of it now, along with any representative regions
+                                   in the region list.
+                                */
+
+                                RegionFactory::remove_regions_using_source (i->second);
+                                sources.erase (i);
+                        }
+               }
+
+                i = tmp;
        }
 
        char tmppath1[PATH_MAX+1];
        char tmppath2[PATH_MAX+1];
-       
-       for (vector<string*>::iterator x = soundfiles->begin(); x != soundfiles->end(); ++x) {
 
-               used = false;
-               spath = **x;
+        if (candidates) {
+                for (vector<string*>::iterator x = candidates->begin(); x != candidates->end(); ++x) {
 
-               for (set<string>::iterator i = all_sources.begin(); i != all_sources.end(); ++i) {
+                        used = false;
+                        spath = **x;
 
-                       realpath(spath.c_str(), tmppath1);
-                       realpath((*i).c_str(),  tmppath2);
+                        for (set<string>::iterator i = all_sources.begin(); i != all_sources.end(); ++i) {
 
-                       if (strcmp(tmppath1, tmppath2) == 0) {
-                               used = true;
-                               break;
-                       }
-               }
+                                if (realpath(spath.c_str(), tmppath1) == 0) {
+                                        error << string_compose (_("Cannot expand path %1 (%2)"),
+                                                                 spath, strerror (errno)) << endmsg;
+                                        continue;
+                                }
 
-               if (!used) {
-                       unused.push_back (spath);
-               }
-       }
+                                if (realpath((*i).c_str(),  tmppath2) == 0) {
+                                        error << string_compose (_("Cannot expand path %1 (%2)"),
+                                                                 (*i), strerror (errno)) << endmsg;
+                                        continue;
+                                }
+
+                                if (strcmp(tmppath1, tmppath2) == 0) {
+                                        used = true;
+                                        break;
+                                }
+                        }
+
+                        if (!used) {
+                                unused.push_back (spath);
+                        }
+
+                        delete *x;
+                }
 
-       /* now try to move all unused files into the "dead_sounds" directory(ies) */
+                delete candidates;
+        }
+
+       /* now try to move all unused files into the "dead" directory(ies) */
 
        for (vector<string>::iterator x = unused.begin(); x != unused.end(); ++x) {
                struct stat statbuf;
 
-               rep.paths.push_back (*x);
-               if (stat ((*x).c_str(), &statbuf) == 0) {
-                       rep.space += statbuf.st_size;
-               }
-
                string newpath;
-               
+
                /* don't move the file across filesystems, just
-                  stick it in the `dead_sound_dir_name' directory
+                  stick it in the `dead_dir_name' directory
                   on whichever filesystem it was already on.
                */
 
@@ -2594,46 +2858,44 @@ Session::cleanup_sources (Session::cleanup_report& rep)
 
                        /* old school, go up 1 level */
 
-                       newpath = Glib::path_get_dirname (*x);      // "sounds" 
+                       newpath = Glib::path_get_dirname (*x);      // "sounds"
                        newpath = Glib::path_get_dirname (newpath); // "session-name"
 
                } else {
 
                        /* new school, go up 4 levels */
-                       
-                       newpath = Glib::path_get_dirname (*x);      // "audiofiles" 
+
+                       newpath = Glib::path_get_dirname (*x);      // "audiofiles" or "midifiles"
                        newpath = Glib::path_get_dirname (newpath); // "session-name"
                        newpath = Glib::path_get_dirname (newpath); // "interchange"
                        newpath = Glib::path_get_dirname (newpath); // "session-dir"
                }
 
-               newpath += '/';
-               newpath += dead_sound_dir_name;
+               newpath = Glib::build_filename (newpath, dead_dir_name);
 
                if (g_mkdir_with_parents (newpath.c_str(), 0755) < 0) {
-                       error << string_compose(_("Session: cannot create session peakfile folder \"%1\" (%2)"), newpath, strerror (errno)) << endmsg;
+                       error << string_compose(_("Session: cannot create dead file folder \"%1\" (%2)"), newpath, strerror (errno)) << endmsg;
                        return -1;
                }
 
-               newpath += '/';
-               newpath += Glib::path_get_basename ((*x));
-               
-               if (access (newpath.c_str(), F_OK) == 0) {
-                       
+               newpath = Glib::build_filename (newpath, Glib::path_get_basename ((*x)));
+
+               if (Glib::file_test (newpath, Glib::FILE_TEST_EXISTS)) {
+
                        /* the new path already exists, try versioning */
-                       
+
                        char buf[PATH_MAX+1];
                        int version = 1;
                        string newpath_v;
-                       
+
                        snprintf (buf, sizeof (buf), "%s.%d", newpath.c_str(), version);
                        newpath_v = buf;
 
-                       while (access (newpath_v.c_str(), F_OK) == 0 && version < 999) {
+                       while (Glib::file_test (newpath_v.c_str(), Glib::FILE_TEST_EXISTS) && version < 999) {
                                snprintf (buf, sizeof (buf), "%s.%d", newpath.c_str(), ++version);
                                newpath_v = buf;
                        }
-                       
+
                        if (version == 999) {
                                error << string_compose (_("there are already 1000 files with names like %1; versioning discontinued"),
                                                  newpath)
@@ -2641,15 +2903,17 @@ Session::cleanup_sources (Session::cleanup_report& rep)
                        } else {
                                newpath = newpath_v;
                        }
-                       
+
                } else {
-                       
+
                        /* it doesn't exist, or we can't read it or something */
-                       
+
                }
 
+               stat ((*x).c_str(), &statbuf);
+
                if (::rename ((*x).c_str(), newpath.c_str()) != 0) {
-                       error << string_compose (_("cannot rename audio file source from %1 to %2 (%3)"),
+                       error << string_compose (_("cannot rename unused file source from %1 to %2 (%3)"),
                                          (*x), newpath, strerror (errno))
                              << endmsg;
                        goto out;
@@ -2658,22 +2922,27 @@ Session::cleanup_sources (Session::cleanup_report& rep)
                /* see if there an easy to find peakfile for this file, and remove it.
                 */
 
-               string peakpath = (*x).substr (0, (*x).find_last_of ('.'));
-               peakpath += peakfile_suffix;
+                string base = basename_nosuffix (*x);
+                base += "%A"; /* this is what we add for the channel suffix of all native files,
+                                 or for the first channel of embedded files. it will miss
+                                 some peakfiles for other channels
+                              */
+               string peakpath = peak_path (base);
 
-               if (access (peakpath.c_str(), W_OK) == 0) {
+               if (Glib::file_test (peakpath.c_str(), Glib::FILE_TEST_EXISTS)) {
                        if (::unlink (peakpath.c_str()) != 0) {
                                error << string_compose (_("cannot remove peakfile %1 for %2 (%3)"),
-                                                 peakpath, _path, strerror (errno))
+                                                         peakpath, _path, strerror (errno))
                                      << endmsg;
                                /* try to back out */
-                               rename (newpath.c_str(), _path.c_str());
+                               ::rename (newpath.c_str(), _path.c_str());
                                goto out;
                        }
                }
-       }
 
-       ret = 0;
+               rep.paths.push_back (*x);
+                rep.space += statbuf.st_size;
+        }
 
        /* dump the history list */
 
@@ -2682,8 +2951,9 @@ Session::cleanup_sources (Session::cleanup_report& rep)
        /* save state so we don't end up a session file
           referring to non-existent sources.
        */
-       
+
        save_state ("");
+       ret = 0;
 
   out:
        _state_of_the_state = (StateOfTheState) (_state_of_the_state & ~InCleanup);
@@ -2692,63 +2962,21 @@ Session::cleanup_sources (Session::cleanup_report& rep)
 }
 
 int
-Session::cleanup_trash_sources (Session::cleanup_report& rep)
+Session::cleanup_trash_sources (CleanupReport& rep)
 {
        // FIXME: needs adaptation for MIDI
-       
+
        vector<space_and_path>::iterator i;
-       string dead_sound_dir;
-       struct dirent* dentry;
-       struct stat statbuf;
-       DIR* dead;
+       string dead_dir;
 
        rep.paths.clear ();
        rep.space = 0;
 
        for (i = session_dirs.begin(); i != session_dirs.end(); ++i) {
-               
-               dead_sound_dir = (*i).path;
-               dead_sound_dir += dead_sound_dir_name;
-
-               if ((dead = opendir (dead_sound_dir.c_str())) == 0) {
-                       continue;
-               }
-
-               while ((dentry = readdir (dead)) != 0) {
-
-                       /* avoid '.' and '..' */
-                       
-                       if ((dentry->d_name[0] == '.' && dentry->d_name[1] == '\0') || 
-                           (dentry->d_name[2] == '\0' && dentry->d_name[0] == '.' && dentry->d_name[1] == '.')) {
-                               continue;
-                       }
-
-                       string fullpath;
-
-                       fullpath = dead_sound_dir;
-                       fullpath += '/';
-                       fullpath += dentry->d_name;
-
-                       if (stat (fullpath.c_str(), &statbuf)) {
-                               continue;
-                       }
-
-                       if (!S_ISREG (statbuf.st_mode)) {
-                               continue;
-                       }
 
-                       if (unlink (fullpath.c_str())) {
-                               error << string_compose (_("cannot remove dead sound file %1 (%2)"),
-                                                 fullpath, strerror (errno))
-                                     << endmsg;
-                       }
+               dead_dir = Glib::build_filename ((*i).path, dead_dir_name);
 
-                       rep.paths.push_back (dentry->d_name);
-                       rep.space += statbuf.st_size;
-               }
-
-               closedir (dead);
-               
+                clear_directory (dead_dir, &rep.space, &rep.paths);
        }
 
        return 0;
@@ -2772,7 +3000,7 @@ void
 Session::set_clean ()
 {
        bool was_dirty = dirty();
-       
+
        _state_of_the_state = Clean;
 
 
@@ -2805,7 +3033,7 @@ Session::add_controllable (boost::shared_ptr<Controllable> c)
        Glib::Mutex::Lock lm (controllables_lock);
        controllables.insert (c);
 }
-       
+
 struct null_deleter { void operator()(void const *) const {} };
 
 void
@@ -2817,19 +3045,18 @@ Session::remove_controllable (Controllable* c)
 
        Glib::Mutex::Lock lm (controllables_lock);
 
-       Controllables::iterator x = controllables.find(
-                boost::shared_ptr<Controllable>(c, null_deleter()));
+       Controllables::iterator x = controllables.find (boost::shared_ptr<Controllable>(c, null_deleter()));
 
        if (x != controllables.end()) {
                controllables.erase (x);
        }
-}      
+}
 
 boost::shared_ptr<Controllable>
 Session::controllable_by_id (const PBD::ID& id)
 {
        Glib::Mutex::Lock lm (controllables_lock);
-       
+
        for (Controllables::iterator i = controllables.begin(); i != controllables.end(); ++i) {
                if ((*i)->id() == id) {
                        return *i;
@@ -2839,10 +3066,142 @@ Session::controllable_by_id (const PBD::ID& id)
        return boost::shared_ptr<Controllable>();
 }
 
-void 
+boost::shared_ptr<Controllable>
+Session::controllable_by_descriptor (const ControllableDescriptor& desc)
+{
+       boost::shared_ptr<Controllable> c;
+       boost::shared_ptr<Route> r;
+
+       switch (desc.top_level_type()) {
+       case ControllableDescriptor::NamedRoute:
+       {
+               std::string str = desc.top_level_name();
+               if (str == "master") {
+                       r = _master_out;
+               } else if (str == "control" || str == "listen") {
+                       r = _monitor_out;
+               } else {
+                       r = route_by_name (desc.top_level_name());
+               }
+               break;
+       }
+
+       case ControllableDescriptor::RemoteControlID:
+               r = route_by_remote_id (desc.rid());
+               break;
+       }
+
+       if (!r) {
+               return c;
+       }
+
+       switch (desc.subtype()) {
+       case ControllableDescriptor::Gain:
+               c = r->gain_control ();
+               break;
+
+       case ControllableDescriptor::Solo:
+                c = r->solo_control();
+               break;
+
+       case ControllableDescriptor::Mute:
+               c = r->mute_control();
+               break;
+
+       case ControllableDescriptor::Recenable:
+       {
+               boost::shared_ptr<Track> t = boost::dynamic_pointer_cast<Track>(r);
+
+               if (t) {
+                       c = t->rec_enable_control ();
+               }
+               break;
+       }
+
+       case ControllableDescriptor::PanDirection:
+        {
+                c = r->pannable()->pan_azimuth_control;
+               break;
+        }
+
+       case ControllableDescriptor::PanWidth:
+        {
+                c = r->pannable()->pan_width_control;
+               break;
+        }
+
+       case ControllableDescriptor::PanElevation:
+        {
+                c = r->pannable()->pan_elevation_control;
+               break;
+        }
+
+       case ControllableDescriptor::Balance:
+               /* XXX simple pan control */
+               break;
+
+       case ControllableDescriptor::PluginParameter:
+       {
+               uint32_t plugin = desc.target (0);
+               uint32_t parameter_index = desc.target (1);
+
+               /* revert to zero based counting */
+
+               if (plugin > 0) {
+                       --plugin;
+               }
+
+               if (parameter_index > 0) {
+                       --parameter_index;
+               }
+
+               boost::shared_ptr<Processor> p = r->nth_plugin (plugin);
+
+               if (p) {
+                       c = boost::dynamic_pointer_cast<ARDOUR::AutomationControl>(
+                               p->control(Evoral::Parameter(PluginAutomation, 0, parameter_index)));
+               }
+               break;
+       }
+
+       case ControllableDescriptor::SendGain:
+       {
+               uint32_t send = desc.target (0);
+
+               /* revert to zero-based counting */
+
+               if (send > 0) {
+                       --send;
+               }
+
+               boost::shared_ptr<Processor> p = r->nth_send (send);
+
+               if (p) {
+                       boost::shared_ptr<Send> s = boost::dynamic_pointer_cast<Send>(p);
+                       boost::shared_ptr<Amp> a = s->amp();
+
+                       if (a) {
+                               c = s->amp()->gain_control();
+                       }
+               }
+               break;
+       }
+
+       default:
+               /* relax and return a null pointer */
+               break;
+       }
+
+       return c;
+}
+
+void
 Session::add_instant_xml (XMLNode& node, bool write_to_config)
 {
-       Stateful::add_instant_xml (node, _path);
+       if (_writable) {
+               Stateful::add_instant_xml (node, _path);
+       }
+
        if (write_to_config) {
                Config->add_instant_xml (node);
        }
@@ -2854,18 +3213,22 @@ Session::instant_xml (const string& node_name)
        return Stateful::instant_xml (node_name, _path);
 }
 
-int 
+int
 Session::save_history (string snapshot_name)
 {
        XMLTree tree;
-       
-       if (snapshot_name.empty()) {
+
+       if (!_writable) {
+               return 0;
+       }
+
+       if (snapshot_name.empty()) {
                snapshot_name = _current_snapshot_name;
        }
-  
-       const string history_filename = snapshot_name + history_suffix;
+
+       const string history_filename = legalize_for_path (snapshot_name) + history_suffix;
        const string backup_filename = history_filename + backup_suffix;
-       const sys::path xml_path = _session_dir->root_path() / history_filename;
+       const sys::path xml_path = _session_dir->root_path() / history_filename;
        const sys::path backup_path = _session_dir->root_path() / backup_filename;
 
        if (sys::exists (xml_path)) {
@@ -2878,14 +3241,13 @@ Session::save_history (string snapshot_name)
                        error << _("could not backup old history file, current history not saved") << endmsg;
                        return -1;
                }
-       }
-
+       }
 
        if (!Config->get_save_history() || Config->get_saved_history_depth() < 0) {
                return 0;
        }
 
-       tree.set_root (&_history.get_state (Config->get_saved_history_depth()));
+       tree.set_root (&_history.get_state (Config->get_saved_history_depth()));
 
        if (!tree.write (xml_path.to_string()))
        {
@@ -2917,10 +3279,10 @@ Session::restore_history (string snapshot_name)
                snapshot_name = _current_snapshot_name;
        }
 
-       const string xml_filename = snapshot_name + history_suffix;
+       const string xml_filename = legalize_for_path (snapshot_name) + history_suffix;
        const sys::path xml_path = _session_dir->root_path() / xml_filename;
 
-    cerr << "Loading history from " << xml_path.to_string() << endmsg;
+       info << "Loading history from " << xml_path.to_string() << endmsg;
 
        if (!sys::exists (xml_path)) {
                info << string_compose (_("%1: no history file \"%2\" for this session."),
@@ -2937,57 +3299,78 @@ Session::restore_history (string snapshot_name)
        // replace history
        _history.clear();
 
-    for (XMLNodeConstIterator it  = tree.root()->children().begin(); it != tree.root()->children().end(); it++) {
-           
-           XMLNode *t = *it;
-           UndoTransaction* ut = new UndoTransaction ();
-           struct timeval tv;
-           
-           ut->set_name(t->property("name")->value());
-           stringstream ss(t->property("tv-sec")->value());
-           ss >> tv.tv_sec;
-           ss.str(t->property("tv-usec")->value());
-           ss >> tv.tv_usec;
-           ut->set_timestamp(tv);
-           
-           for (XMLNodeConstIterator child_it  = t->children().begin();
+       for (XMLNodeConstIterator it  = tree.root()->children().begin(); it != tree.root()->children().end(); it++) {
+
+               XMLNode *t = *it;
+               UndoTransaction* ut = new UndoTransaction ();
+               struct timeval tv;
+
+               ut->set_name(t->property("name")->value());
+               stringstream ss(t->property("tv-sec")->value());
+               ss >> tv.tv_sec;
+               ss.str(t->property("tv-usec")->value());
+               ss >> tv.tv_usec;
+               ut->set_timestamp(tv);
+
+               for (XMLNodeConstIterator child_it  = t->children().begin();
                                child_it != t->children().end(); child_it++)
-           {
-                   XMLNode *n = *child_it;
-                   Command *c;
-       
-                   if (n->name() == "MementoCommand" ||
+               {
+                       XMLNode *n = *child_it;
+                       Command *c;
+
+                       if (n->name() == "MementoCommand" ||
                                        n->name() == "MementoUndoCommand" ||
                                        n->name() == "MementoRedoCommand") {
 
-                           if ((c = memento_command_factory(n))) {
-                                   ut->add_command(c);
-                           }
-                           
-                   } else if (n->name() == X_("GlobalRouteStateCommand")) {
-
-                           if ((c = global_state_command_factory (*n))) {
-                                   ut->add_command (c);
-                           }
-                           
-                   } else if (n->name() == "DeltaCommand") {
-                        PBD::ID  id(n->property("midi-source")->value());
-                        boost::shared_ptr<MidiSource> midi_source = 
-                                boost::dynamic_pointer_cast<MidiSource, Source>(source_by_id(id));
-                        if(midi_source) {
-                                ut->add_command(new MidiModel::DeltaCommand(midi_source->model(), *n));                                 
-                        } else {
-                                error << "FIXME: Failed to downcast MidiSource for DeltaCommand" << endmsg;
-                        }
-                   } else {
-                           error << string_compose(_("Couldn't figure out how to make a Command out of a %1 XMLNode."), n->name()) << endmsg;
-                   }
-           }
-
-           _history.add (ut);
-    }
-
-    return 0;
+                               if ((c = memento_command_factory(n))) {
+                                       ut->add_command(c);
+                               }
+
+                       } else if (n->name() == "NoteDiffCommand") {
+                               PBD::ID id (n->property("midi-source")->value());
+                               boost::shared_ptr<MidiSource> midi_source =
+                                       boost::dynamic_pointer_cast<MidiSource, Source>(source_by_id(id));
+                               if (midi_source) {
+                                       ut->add_command (new MidiModel::NoteDiffCommand(midi_source->model(), *n));
+                               } else {
+                                       error << _("Failed to downcast MidiSource for NoteDiffCommand") << endmsg;
+                               }
+
+                       } else if (n->name() == "SysExDiffCommand") {
+
+                               PBD::ID id (n->property("midi-source")->value());
+                               boost::shared_ptr<MidiSource> midi_source =
+                                       boost::dynamic_pointer_cast<MidiSource, Source>(source_by_id(id));
+                               if (midi_source) {
+                                       ut->add_command (new MidiModel::SysExDiffCommand (midi_source->model(), *n));
+                               } else {
+                                       error << _("Failed to downcast MidiSource for SysExDiffCommand") << endmsg;
+                               }
+
+                       } else if (n->name() == "PatchChangeDiffCommand") {
+
+                               PBD::ID id (n->property("midi-source")->value());
+                               boost::shared_ptr<MidiSource> midi_source =
+                                       boost::dynamic_pointer_cast<MidiSource, Source>(source_by_id(id));
+                               if (midi_source) {
+                                       ut->add_command (new MidiModel::PatchChangeDiffCommand (midi_source->model(), *n));
+                               } else {
+                                       error << _("Failed to downcast MidiSource for PatchChangeDiffCommand") << endmsg;
+                               }
+
+                       } else if (n->name() == "StatefulDiffCommand") {
+                               if ((c = stateful_diff_command_factory (n))) {
+                                       ut->add_command (c);
+                               }
+                       } else {
+                               error << string_compose(_("Couldn't figure out how to make a Command out of a %1 XMLNode."), n->name()) << endmsg;
+                       }
+               }
+
+               _history.add (ut);
+       }
+
+       return 0;
 }
 
 void
@@ -2996,58 +3379,51 @@ Session::config_changed (std::string p, bool ours)
        if (ours) {
                set_dirty ();
        }
-       
+
        if (p == "seamless-loop") {
-               
+
        } else if (p == "rf-speed") {
-               
+
        } else if (p == "auto-loop") {
-               
+
        } else if (p == "auto-input") {
-               
+
                if (Config->get_monitoring_model() == HardwareMonitoring && transport_rolling()) {
                        /* auto-input only makes a difference if we're rolling */
-                       
-                       boost::shared_ptr<DiskstreamList> dsl = diskstreams.reader();
-                       
-                       for (DiskstreamList::iterator i = dsl->begin(); i != dsl->end(); ++i) {
-                               if ((*i)->record_enabled ()) {
-                                       (*i)->monitor_input (!config.get_auto_input());
-                               }
-                       }
+                        set_track_monitor_input_status (!config.get_auto_input());
                }
 
        } else if (p == "punch-in") {
 
                Location* location;
-               
-               if ((location = _locations.auto_punch_location()) != 0) {
-                       
+
+               if ((location = _locations->auto_punch_location()) != 0) {
+
                        if (config.get_punch_in ()) {
-                               replace_event (Event::PunchIn, location->start());
+                               replace_event (SessionEvent::PunchIn, location->start());
                        } else {
-                               remove_event (location->start(), Event::PunchIn);
+                               remove_event (location->start(), SessionEvent::PunchIn);
                        }
                }
-               
+
        } else if (p == "punch-out") {
 
                Location* location;
-               
-               if ((location = _locations.auto_punch_location()) != 0) {
-                       
+
+               if ((location = _locations->auto_punch_location()) != 0) {
+
                        if (config.get_punch_out()) {
-                               replace_event (Event::PunchOut, location->end());
+                               replace_event (SessionEvent::PunchOut, location->end());
                        } else {
-                               clear_events (Event::PunchOut);
+                               clear_events (SessionEvent::PunchOut);
                        }
                }
 
        } else if (p == "edit-mode") {
 
-               Glib::Mutex::Lock lm (playlist_lock);
-               
-               for (PlaylistList::iterator i = playlists.begin(); i != playlists.end(); ++i) {
+               Glib::Mutex::Lock lm (playlists->lock);
+
+               for (SessionPlaylists::List::iterator i = playlists->playlists.begin(); i != playlists->playlists.end(); ++i) {
                        (*i)->set_edit_mode (Config->get_edit_mode ());
                }
 
@@ -3059,27 +3435,23 @@ Session::config_changed (std::string p, bool ours)
 
                //poke_midi_thread ();
 
-       } else if (p == "mmc-device-id" || p == "mmc-receive-id") {
+       } else if (p == "mmc-device-id" || p == "mmc-receive-id" || p == "mmc-receive-device-id") {
 
-               if (mmc) {
-                       mmc->set_receive_device_id (Config->get_mmc_receive_device_id());
-               }
+               MIDI::Manager::instance()->mmc()->set_receive_device_id (Config->get_mmc_receive_device_id());
 
-       } else if (p == "mmc-send-id") {
+       } else if (p == "mmc-send-id" || p == "mmc-send-device-id") {
 
-               if (mmc) {
-                       mmc->set_send_device_id (Config->get_mmc_send_device_id());
-               }
+               MIDI::Manager::instance()->mmc()->set_send_device_id (Config->get_mmc_send_device_id());
 
        } else if (p == "midi-control") {
-               
+
                //poke_midi_thread ();
 
        } else if (p == "raid-path") {
 
                setup_raid_path (config.get_raid_path());
 
-       } else if (p == "smpte-format") {
+       } else if (p == "timecode-format") {
 
                sync_time_vars ();
 
@@ -3118,43 +3490,19 @@ Session::config_changed (std::string p, bool ours)
                }
 
        } else if (p == "send-mtc") {
-               
-               /* only set the internal flag if we have
-                  a port.
-               */
-               
-               if (_mtc_port != 0) {
-                       session_send_mtc = Config->get_send_mtc();
-                       if (session_send_mtc) {
-                               /* mark us ready to send */
-                               next_quarter_frame_to_send = 0;
-                       }
-               } else {
-                       session_send_mtc = false;
+
+               if (Config->get_send_mtc ()) {
+                       /* mark us ready to send */
+                       next_quarter_frame_to_send = 0;
                }
 
        } else if (p == "send-mmc") {
-               
-               /* only set the internal flag if we have
-                  a port.
-               */
-               
-               if (_mmc_port != 0) {
-                       session_send_mmc = Config->get_send_mmc();
-               } else {
-                       mmc = 0;
-                       session_send_mmc = false; 
-               }
+
+               MIDI::Manager::instance()->mmc()->enable_send (Config->get_send_mmc ());
 
        } else if (p == "midi-feedback") {
-               
-               /* only set the internal flag if we have
-                  a port.
-               */
-               
-               if (_mtc_port != 0) {
-                       session_midi_feedback = Config->get_midi_feedback();
-               }
+
+               session_midi_feedback = Config->get_midi_feedback();
 
        } else if (p == "jack-time-master") {
 
@@ -3176,8 +3524,12 @@ Session::config_changed (std::string p, bool ours)
 
                first_file_data_format_reset = false;
 
-       } else if (p == "slave-source") {
-                               set_slave_source (Config->get_slave_source());
+       } else if (p == "external-sync") {
+               if (!config.get_external_sync()) {
+                       drop_sync_source ();
+               } else {
+                       switch_to_sync_source (config.get_sync_source());
+               }
        } else if (p == "remote-model") {
                set_remote_control_ids ();
        }  else if (p == "denormal-model") {
@@ -3188,27 +3540,24 @@ Session::config_changed (std::string p, bool ours)
                sync_order_keys ("session");
        } else if (p == "initial-program-change") {
 
-               if (_mmc_port && Config->get_initial_program_change() >= 0) {
+               if (MIDI::Manager::instance()->mmc()->output_port() && Config->get_initial_program_change() >= 0) {
                        MIDI::byte buf[2];
-                       
-                       buf[0] = MIDI::program; // channel zero by default
-                       buf[1] = (Config->get_initial_program_change() & 0x7f);
-
-                       _mmc_port->midimsg (buf, sizeof (buf), 0);
-               }
-       } else if (p == "initial-program-change") {
 
-               if (_mmc_port && Config->get_initial_program_change() >= 0) {
-                       MIDI::byte* buf = new MIDI::byte[2];
-                       
                        buf[0] = MIDI::program; // channel zero by default
                        buf[1] = (Config->get_initial_program_change() & 0x7f);
-                       // deliver_midi (_mmc_port, buf, 2);
+
+                       MIDI::Manager::instance()->mmc()->output_port()->midimsg (buf, sizeof (buf), 0);
                }
        } else if (p == "solo-mute-override") {
                // catch_up_on_solo_mute_override ();
-       } else if (p == "solo-model") {
-               solo_model_changed ();
+       } else if (p == "listen-position" || p == "pfl-position") {
+               listen_position_changed ();
+       } else if (p == "solo-control-is-listen-control") {
+               solo_control_mode_changed ();
+       } else if (p == "timecode-offset" || p == "timecode-offset-negative") {
+               last_timecode_valid = false;
+       } else if (p == "playback-buffer-seconds") {
+               AudioSource::allocate_working_buffers (frame_rate());
        }
 
        set_dirty ();
@@ -3219,3 +3568,241 @@ Session::set_history_depth (uint32_t d)
 {
        _history.set_depth (d);
 }
+
+int
+Session::load_diskstreams_2X (XMLNode const & node, int)
+{
+        XMLNodeList          clist;
+        XMLNodeConstIterator citer;
+
+        clist = node.children();
+
+        for (citer = clist.begin(); citer != clist.end(); ++citer) {
+
+                try {
+                        /* diskstreams added automatically by DiskstreamCreated handler */
+                        if ((*citer)->name() == "AudioDiskstream" || (*citer)->name() == "DiskStream") {
+                               boost::shared_ptr<AudioDiskstream> dsp (new AudioDiskstream (*this, **citer));
+                               _diskstreams_2X.push_back (dsp);
+                        } else {
+                                error << _("Session: unknown diskstream type in XML") << endmsg;
+                        }
+                }
+
+                catch (failed_constructor& err) {
+                        error << _("Session: could not load diskstream via XML state") << endmsg;
+                        return -1;
+                }
+        }
+
+        return 0;
+}
+
+/** Connect things to the MMC object */
+void
+Session::setup_midi_machine_control ()
+{
+       MIDI::MachineControl* mmc = MIDI::Manager::instance()->mmc ();
+
+       mmc->Play.connect_same_thread (*this, boost::bind (&Session::mmc_deferred_play, this, _1));
+       mmc->DeferredPlay.connect_same_thread (*this, boost::bind (&Session::mmc_deferred_play, this, _1));
+       mmc->Stop.connect_same_thread (*this, boost::bind (&Session::mmc_stop, this, _1));
+       mmc->FastForward.connect_same_thread (*this, boost::bind (&Session::mmc_fast_forward, this, _1));
+       mmc->Rewind.connect_same_thread (*this, boost::bind (&Session::mmc_rewind, this, _1));
+       mmc->Pause.connect_same_thread (*this, boost::bind (&Session::mmc_pause, this, _1));
+       mmc->RecordPause.connect_same_thread (*this, boost::bind (&Session::mmc_record_pause, this, _1));
+       mmc->RecordStrobe.connect_same_thread (*this, boost::bind (&Session::mmc_record_strobe, this, _1));
+       mmc->RecordExit.connect_same_thread (*this, boost::bind (&Session::mmc_record_exit, this, _1));
+       mmc->Locate.connect_same_thread (*this, boost::bind (&Session::mmc_locate, this, _1, _2));
+       mmc->Step.connect_same_thread (*this, boost::bind (&Session::mmc_step, this, _1, _2));
+       mmc->Shuttle.connect_same_thread (*this, boost::bind (&Session::mmc_shuttle, this, _1, _2, _3));
+       mmc->TrackRecordStatusChange.connect_same_thread (*this, boost::bind (&Session::mmc_record_enable, this, _1, _2, _3));
+
+       /* also handle MIDI SPP because its so common */
+
+       mmc->SPPStart.connect_same_thread (*this, boost::bind (&Session::spp_start, this, _1, _2));
+       mmc->SPPContinue.connect_same_thread (*this, boost::bind (&Session::spp_continue, this, _1, _2));
+       mmc->SPPStop.connect_same_thread (*this, boost::bind (&Session::spp_stop, this, _1, _2));
+}
+
+boost::shared_ptr<Controllable>
+Session::solo_cut_control() const
+{
+        /* the solo cut control is a bit of an anomaly, at least as of Febrary 2011. There are no other
+           controls in Ardour that currently get presented to the user in the GUI that require
+           access as a Controllable and are also NOT owned by some SessionObject (e.g. Route, or MonitorProcessor).
+
+           its actually an RCConfiguration parameter, so we use a ProxyControllable to wrap
+           it up as a Controllable. Changes to the Controllable will just map back to the RCConfiguration
+           parameter.
+        */
+
+        return _solo_cut_control;
+}
+
+int
+Session::rename (const std::string& new_name)
+{
+       string legal_name = legalize_for_path (new_name);
+       string newpath;
+       string oldstr;
+       string newstr;
+       bool first = true;
+
+       string const old_sources_root = _session_dir->sources_root().to_string ();
+
+#define RENAME ::rename
+
+       /* Rename:
+
+        * session directory
+        * interchange subdirectory
+        * session file
+        * session history
+        
+        * Backup files are left unchanged and not renamed.
+        */
+
+       /* pass one: not 100% safe check that the new directory names don't
+        * already exist ...
+        */
+
+       for (vector<space_and_path>::const_iterator i = session_dirs.begin(); i != session_dirs.end(); ++i) {
+               vector<string> v;
+
+               oldstr = (*i).path;
+
+               /* this is a stupid hack because Glib::path_get_dirname() is
+                * lexical-only, and so passing it /a/b/c/ gives a different
+                * result than passing it /a/b/c ...
+                */
+
+               if (oldstr[oldstr.length()-1] == G_DIR_SEPARATOR) {
+                       oldstr = oldstr.substr (0, oldstr.length() - 1);
+               }
+
+               string base = Glib::path_get_dirname (oldstr);
+               string p = Glib::path_get_basename (oldstr);
+
+               newstr = Glib::build_filename (base, legal_name);
+               
+               if (Glib::file_test (newstr, Glib::FILE_TEST_EXISTS)) {
+                       return -1;
+               }
+       }
+
+       /* Session dirs */
+       
+       for (vector<space_and_path>::const_iterator i = session_dirs.begin(); i != session_dirs.end(); ++i) {
+               vector<string> v;
+
+               oldstr = (*i).path;
+
+               /* this is a stupid hack because Glib::path_get_dirname() is
+                * lexical-only, and so passing it /a/b/c/ gives a different
+                * result than passing it /a/b/c ...
+                */
+
+               if (oldstr[oldstr.length()-1] == G_DIR_SEPARATOR) {
+                       oldstr = oldstr.substr (0, oldstr.length() - 1);
+               }
+
+               string base = Glib::path_get_dirname (oldstr);
+               string p = Glib::path_get_basename (oldstr);
+
+               newstr = Glib::build_filename (base, legal_name);
+
+               cerr << "Rename " << oldstr << " => " << newstr << endl;                
+
+               if (RENAME (oldstr.c_str(), newstr.c_str()) != 0) {
+                       return 1;
+               }
+
+               if (first) {
+                       (*_session_dir) = newstr;
+                       newpath = newstr;
+                       first = 1;
+               }
+
+               /* directory below interchange */
+
+               v.push_back (newstr);
+               v.push_back (interchange_dir_name);
+               v.push_back (p);
+
+               oldstr = Glib::build_filename (v);
+
+               v.clear ();
+               v.push_back (newstr);
+               v.push_back (interchange_dir_name);
+               v.push_back (legal_name);
+
+               newstr = Glib::build_filename (v);
+               
+               cerr << "Rename " << oldstr << " => " << newstr << endl;
+               
+               if (RENAME (oldstr.c_str(), newstr.c_str()) != 0) {
+                       return 1;
+               }
+       }
+
+       /* state file */
+       
+       oldstr = Glib::build_filename (newpath, _current_snapshot_name) + statefile_suffix;
+       newstr= Glib::build_filename (newpath, legal_name) + statefile_suffix;
+       
+       cerr << "Rename " << oldstr << " => " << newstr << endl;                
+
+       if (RENAME (oldstr.c_str(), newstr.c_str()) != 0) {
+               return 1;
+       }
+
+       /* history file */
+
+       
+       oldstr = Glib::build_filename (newpath, _current_snapshot_name) + history_suffix;
+
+       if (Glib::file_test (oldstr, Glib::FILE_TEST_EXISTS))  {
+               newstr = Glib::build_filename (newpath, legal_name) + history_suffix;
+               
+               cerr << "Rename " << oldstr << " => " << newstr << endl;                
+               
+               if (RENAME (oldstr.c_str(), newstr.c_str()) != 0) {
+                       return 1;
+               }
+       }
+
+       /* update file source paths */
+       
+       for (SourceMap::iterator i = sources.begin(); i != sources.end(); ++i) {
+               boost::shared_ptr<FileSource> fs = boost::dynamic_pointer_cast<FileSource> (i->second);
+               if (fs) {
+                       string p = fs->path ();
+                       boost::replace_all (p, old_sources_root, _session_dir->sources_root().to_string ());
+                       fs->set_path (p);
+               }
+       }
+
+       /* remove old name from recent sessions */
+
+       remove_recent_sessions (_path);
+
+       _path = newpath;
+       _current_snapshot_name = new_name;
+       _name = new_name;
+
+       set_dirty ();
+
+       /* save state again to get everything just right */
+
+       save_state (_current_snapshot_name);
+
+
+       /* add to recent sessions */
+
+       store_recent_sessions (new_name, _path);
+
+       return 0;
+
+#undef RENAME
+}