first pass on track mode switch; fixes to dangling region refs after capture; destroy region menu item removed; small fix to SConstruct for missing C++ case; playlist selection mechanism modified ; new Selection operation added (Add); handle crashing situation with align style change handling caused by recursion

git-svn-id: svn://localhost/ardour2/trunk@1099 d708f5d6-7413-0410-9779-e7cbd77b26cf

23 files changed, 277 insertions, 80 deletions

diff --git a/libs/ardour/SConscript b/libs/ardour/SConscript
index 8c6bd36c2d..7d1520a98c 100644
--- a/libs/ardour/SConscript
+++ b/libs/ardour/SConscript
@@ -274,7 +274,6 @@ if env['NLS']:
 
 env.Alias('install', env.Install(os.path.join(install_prefix, 'lib/ardour2'), libardour))
 
-env.AlwaysBuild ('version.cc')	      
 env.Alias('version', ardour.VersionBuild(['version.cc', 'ardour/version.h'], 'SConscript'))
 
 env.Alias('tarball', env.Distribute (env['DISTTREE'],
diff --git a/libs/ardour/ardour/audio_diskstream.h b/libs/ardour/ardour/audio_diskstream.h
index 4dee5e9b00..74c804e5bb 100644
--- a/libs/ardour/ardour/audio_diskstream.h
+++ b/libs/ardour/ardour/audio_diskstream.h
@@ -77,6 +77,7 @@ class AudioDiskstream : public Diskstream
 	}
 
 	void set_record_enabled (bool yn);
+	int set_destructive (bool yn);
 
 	float peak_power(uint32_t n=0) { 
 		float x = channels[n].peak_power;
@@ -251,6 +252,8 @@ class AudioDiskstream : public Diskstream
 	
 	typedef vector<ChannelInfo> ChannelList;
 	ChannelList channels;
+
+	bool can_become_destructive () const;
 };
 
 } // namespace ARDOUR
diff --git a/libs/ardour/ardour/audio_track.h b/libs/ardour/ardour/audio_track.h
index 66fcd16a56..ae299dae4a 100644
--- a/libs/ardour/ardour/audio_track.h
+++ b/libs/ardour/ardour/audio_track.h
@@ -37,6 +37,8 @@ class AudioTrack : public Track
 	AudioTrack (Session&, const XMLNode&);
 	~AudioTrack ();
 
+	int set_mode (TrackMode m); 
+
 	int roll (nframes_t nframes, nframes_t start_frame, nframes_t end_frame, 
 		nframes_t offset, int declick, bool can_record, bool rec_monitors_input);
 	
diff --git a/libs/ardour/ardour/audioregion.h b/libs/ardour/ardour/audioregion.h
index 4be5d27a6b..b739935d96 100644
--- a/libs/ardour/ardour/audioregion.h
+++ b/libs/ardour/ardour/audioregion.h
@@ -136,6 +136,8 @@ class AudioRegion : public Region
 	void resume_fade_in ();
 	void resume_fade_out ();
 
+	void set_playlist (Playlist *);
+
   private:
 	friend class RegionFactory;
 
diff --git a/libs/ardour/ardour/diskstream.h b/libs/ardour/ardour/diskstream.h
index 0afed75348..4cee6d1268 100644
--- a/libs/ardour/ardour/diskstream.h
+++ b/libs/ardour/ardour/diskstream.h
@@ -90,7 +90,7 @@ class IO;
 	virtual void set_record_enabled (bool yn) = 0;
 
 	bool destructive() const { return _flags & Destructive; }
-	virtual void set_destructive (bool yn);
+	virtual int set_destructive (bool yn) { return -1; }
 
 	bool           hidden()      const { return _flags & Hidden; }
 	bool           recordable()  const { return _flags & Recordable; }
@@ -138,6 +138,8 @@ class IO;
 
 	void handle_input_change (IOChange, void *src);
 
+	void remove_region_from_last_capture (boost::weak_ptr<Region> wregion);
+
 	sigc::signal<void>            RecordEnableChanged;
 	sigc::signal<void>            SpeedChanged;
 	sigc::signal<void>            ReverseChanged;
@@ -224,6 +226,7 @@ class IO;
 	virtual bool realtime_set_speed (double, bool global_change);
 
 	std::list<boost::shared_ptr<Region> > _last_capture_regions;
+
 	virtual int use_pending_capture_data (XMLNode& node) = 0;
 
 	virtual void get_input_sources () = 0;
diff --git a/libs/ardour/ardour/playlist.h b/libs/ardour/ardour/playlist.h
index 9cc3f86f0b..7b9ae718bc 100644
--- a/libs/ardour/ardour/playlist.h
+++ b/libs/ardour/ardour/playlist.h
@@ -62,14 +62,15 @@ class Playlist : public PBD::StatefulDestructible {
 	void unref();
 	uint32_t refcnt() const { return _refcnt; }
 
-	const string& name() const { return _name; }
-	void set_name (const string& str);
+	std::string name() const { return _name; }
+	void set_name (std::string str);
 
 	bool frozen() const { return _frozen; }
 	void set_frozen (bool yn);
 
 	bool hidden() const { return _hidden; }
 	bool empty() const;
+	uint32_t n_regions() const;
 	nframes_t get_maximum_extent () const;
 	layer_t top_layer() const;
 
@@ -88,19 +89,15 @@ class Playlist : public PBD::StatefulDestructible {
 	void duplicate (boost::shared_ptr<Region>, nframes_t position, float times);
 	void nudge_after (nframes_t start, nframes_t distance, bool forwards);
 
-	boost::shared_ptr<Region> find_region (const PBD::ID&) const;
-
 	Playlist* cut  (list<AudioRange>&, bool result_is_hidden = true);
 	Playlist* copy (list<AudioRange>&, bool result_is_hidden = true);
 	int       paste (Playlist&, nframes_t position, float times);
 
-	uint32_t read_data_count() { return _read_data_count; }
-
-	RegionList* regions_at (nframes_t frame);
-	RegionList* regions_touched (nframes_t start, nframes_t end);
+	RegionList*                regions_at (nframes_t frame);
+	RegionList*                regions_touched (nframes_t start, nframes_t end);
+	boost::shared_ptr<Region>  find_region (const PBD::ID&) const;
 	boost::shared_ptr<Region>  top_region_at (nframes_t frame);
-
-	boost::shared_ptr<Region>     find_next_region (nframes_t frame, RegionPoint point, int dir);
+	boost::shared_ptr<Region>  find_next_region (nframes_t frame, RegionPoint point, int dir);
 
 	template<class T> void foreach_region (T *t, void (T::*func)(boost::shared_ptr<Region>, void *), void *arg);
 	template<class T> void foreach_region (T *t, void (T::*func)(boost::shared_ptr<Region>));
diff --git a/libs/ardour/ardour/region.h b/libs/ardour/ardour/region.h
index 67e00d0ee8..7f511c4dd4 100644
--- a/libs/ardour/ardour/region.h
+++ b/libs/ardour/ardour/region.h
@@ -163,10 +163,7 @@ class Region : public PBD::StatefulDestructible, public boost::enable_shared_fro
 
 	ARDOUR::Playlist* playlist() const { return _playlist; }
 
-	void set_playlist (ARDOUR::Playlist*);
-
-	virtual void lock_sources () {}
-	virtual void unlock_sources () {}
+	virtual void set_playlist (ARDOUR::Playlist*);
 
 	/* serialization */
 	
diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index 85c0ef508c..93c093ec85 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -542,8 +542,8 @@ class Session : public PBD::StatefulDestructible
 	
 	/* region info  */
 
-	sigc::signal<void,boost::shared_ptr<AudioRegion> > AudioRegionAdded;
-	sigc::signal<void,boost::shared_ptr<AudioRegion> > AudioRegionRemoved;
+	sigc::signal<void,boost::weak_ptr<AudioRegion> > AudioRegionAdded;
+	sigc::signal<void,boost::weak_ptr<AudioRegion> > AudioRegionRemoved;
 
 	int region_name (string& result, string base = string(""), bool newlevel = false) const;
 	string new_region_name (string);
@@ -630,6 +630,7 @@ class Session : public PBD::StatefulDestructible
 	uint32_t n_playlists() const;
 
 	template<class T> void foreach_playlist (T *obj, void (T::*func)(Playlist *));
+	void get_playlists (std::vector<Playlist*>&);
 
 	/* named selections */
 
diff --git a/libs/ardour/ardour/source.h b/libs/ardour/ardour/source.h
index 7e05e628ac..15e814e946 100644
--- a/libs/ardour/ardour/source.h
+++ b/libs/ardour/ardour/source.h
@@ -22,6 +22,7 @@
 #define __ardour_source_h__
 
 #include <string>
+#include <set>
 
 #include <sigc++/signal.h>
 
@@ -32,6 +33,7 @@
 namespace ARDOUR {
 
 class Session;
+class Playlist;
 
 class Source : public PBD::StatefulDestructible
 {
@@ -49,13 +51,23 @@ class Source : public PBD::StatefulDestructible
 	XMLNode& get_state ();
 	int set_state (const XMLNode&);
 
+	void use () { _in_use++; }
+	void disuse () { if (_in_use) { _in_use--; } }
+
+	void add_playlist (ARDOUR::Playlist*);
+	void remove_playlist (ARDOUR::Playlist*);
+
+	uint32_t used() const;
 
   protected:
 	Session&          _session;
 	string            _name;
 	time_t            _timestamp;
 
+	std::set<ARDOUR::Playlist*> _playlists;
+
   private:
+	uint32_t          _in_use;
 };
 
 }
diff --git a/libs/ardour/ardour/track.h b/libs/ardour/ardour/track.h
index cf380de153..a24b614157 100644
--- a/libs/ardour/ardour/track.h
+++ b/libs/ardour/ardour/track.h
@@ -39,6 +39,10 @@ class Track : public Route
 	
 	int set_name (string str, void *src);
 
+	TrackMode mode () const { return _mode; }
+	virtual int set_mode (TrackMode m) { return false; }
+	sigc::signal<void> TrackModeChanged;
+
 	virtual int roll (nframes_t nframes, nframes_t start_frame, nframes_t end_frame, 
 		nframes_t offset, int declick, bool can_record, bool rec_monitors_input) = 0;
 	
@@ -57,9 +61,6 @@ class Track : public Route
 	virtual int use_diskstream (string name) = 0;
 	virtual int use_diskstream (const PBD::ID& id) = 0;
 
-	TrackMode mode() const { return _mode; }
-	void      set_mode (TrackMode m);
-
 	nframes_t update_total_latency();
 	void           set_latency_delay (nframes_t);
 
@@ -88,7 +89,6 @@ class Track : public Route
 	
 	void set_meter_point (MeterPoint, void* src);
 	
-	sigc::signal<void> ModeChanged;
 	sigc::signal<void> DiskstreamChanged;
 	sigc::signal<void> FreezeChange;
 
diff --git a/libs/ardour/audio_diskstream.cc b/libs/ardour/audio_diskstream.cc
index ad9fec2d41..7e753fa601 100644
--- a/libs/ardour/audio_diskstream.cc
+++ b/libs/ardour/audio_diskstream.cc
@@ -381,7 +381,7 @@ AudioDiskstream::setup_destructive_playlist ()
 void
 AudioDiskstream::use_destructive_playlist ()
 {
-	/* this is called from the XML-based constructor. when its done,
+	/* this is called from the XML-based constructor or ::set_destructive. when called,
 	   we already have a playlist and a region, but we need to
 	   set up our sources for write. we use the sources associated 
 	   with the (presumed single, full-extent) region.
@@ -400,6 +400,10 @@ AudioDiskstream::use_destructive_playlist ()
 		throw failed_constructor();
 	}
 
+	/* be sure to stretch the region out to the maximum length */
+
+	region->set_length (max_frames - region->position(), this);
+
 	uint32_t n;
 	ChannelList::iterator chan;
 
@@ -407,6 +411,10 @@ AudioDiskstream::use_destructive_playlist ()
 		(*chan).write_source = boost::dynamic_pointer_cast<AudioFileSource>(region->source (n));
 		assert((*chan).write_source);
 		(*chan).write_source->set_allow_remove_if_empty (false);
+
+		/* this might be false if we switched modes, so force it */
+
+		(*chan).write_source->set_destructive (true);
 	}
 
 	/* the source list will never be reset for a destructive track */
@@ -1584,9 +1592,9 @@ AudioDiskstream::transport_stopped (struct tm& when, time_t twhen, bool abort_ca
 				continue; /* XXX is this OK? */
 			}
 			
-			_last_capture_regions.push_back (region);
+			region->GoingAway.connect (bind (mem_fun (*this, &Diskstream::remove_region_from_last_capture), boost::weak_ptr<Region>(region)));
 			
-			// cerr << "add new region, buffer position = " << buffer_position << " @ " << (*ci)->start << endl;
+			_last_capture_regions.push_back (region);
 			
 			i_am_the_modifier++;
 			_playlist->add_region (region, (*ci)->start);
@@ -2228,3 +2236,60 @@ AudioDiskstream::use_pending_capture_data (XMLNode& node)
 
 	return 0;
 }
+
+int
+AudioDiskstream::set_destructive (bool yn)
+{
+	if (yn != destructive()) {
+		
+		if (yn) {
+			if (!can_become_destructive ()) {
+				return -1;
+			}
+			_flags |= Destructive;
+			use_destructive_playlist ();
+		} else {
+			_flags &= ~Destructive;
+			reset_write_sources (true, true);
+		}
+	}
+
+	return 0;
+}
+
+bool
+AudioDiskstream::can_become_destructive () const
+{
+	if (!_playlist) {
+		return false;
+	}
+
+	/* is there only one region ? */
+
+	if (_playlist->n_regions() != 1) {
+		return false;
+	}
+
+	boost::shared_ptr<Region> first = _playlist->find_next_region (_session.current_start_frame(), Start, 1);
+	assert (first);
+
+	/* do the source(s) for the region cover the session start position ? */
+	
+	if (first->position() != _session.current_start_frame()) {
+		if (first->start() > _session.current_start_frame()) {
+			return false;
+		}
+	}
+
+	/* is the source used by only 1 playlist ? */
+
+	boost::shared_ptr<AudioRegion> afirst = boost::dynamic_pointer_cast<AudioRegion> (first);
+
+	assert (afirst);
+
+	if (afirst->source()->used() > 1) {
+		return false;
+	}
+
+	return true;
+}
diff --git a/libs/ardour/audio_playlist.cc b/libs/ardour/audio_playlist.cc
index 290907746b..5118aab684 100644
--- a/libs/ardour/audio_playlist.cc
+++ b/libs/ardour/audio_playlist.cc
@@ -624,12 +624,10 @@ AudioPlaylist::destroy_region (boost::shared_ptr<Region> region)
 
 	{ 
 		RegionLock rlock (this);
-		RegionList::iterator i;
-		RegionList::iterator tmp;
 
-		for (i = regions.begin(); i != regions.end(); ) {
+		for (RegionList::iterator i = regions.begin(); i != regions.end(); ) {
 			
-			tmp = i;
+			RegionList::iterator tmp = i;
 			++tmp;
 			
 			if ((*i) == region) {
@@ -639,6 +637,21 @@ AudioPlaylist::destroy_region (boost::shared_ptr<Region> region)
 			
 			i = tmp;
 		}
+
+		for (set<boost::shared_ptr<Region> >::iterator x = all_regions.begin(); x != all_regions.end(); ) {
+
+			set<boost::shared_ptr<Region> >::iterator xtmp = x;
+			++xtmp;
+			
+			if ((*x) == region) {
+				all_regions.erase (x);
+				changed = true;
+			}
+			
+			x = xtmp;
+		}
+
+		region->set_playlist (0);
 	}
 
 	for (c = _crossfades.begin(); c != _crossfades.end(); ) {
diff --git a/libs/ardour/audio_track.cc b/libs/ardour/audio_track.cc
index 23ece02fa8..9c5020e9aa 100644
--- a/libs/ardour/audio_track.cc
+++ b/libs/ardour/audio_track.cc
@@ -73,6 +73,23 @@ AudioTrack::~AudioTrack ()
 }
 
 int
+AudioTrack::set_mode (TrackMode m)
+{
+	if (m != _mode) {
+
+		if (_diskstream->set_destructive (m == Destructive)) {
+			return -1;
+		}
+
+		_mode = m;
+		
+		TrackModeChanged (); /* EMIT SIGNAL */
+	}
+
+	return 0;
+}
+
+int
 AudioTrack::deprecated_use_diskstream_connections ()
 {
 	boost::shared_ptr<AudioDiskstream> diskstream = audio_diskstream();
diff --git a/libs/ardour/audioregion.cc b/libs/ardour/audioregion.cc
index 2f0ae03f2d..a3ba886e38 100644
--- a/libs/ardour/audioregion.cc
+++ b/libs/ardour/audioregion.cc
@@ -306,6 +306,12 @@ AudioRegion::AudioRegion (SourceList& srcs, const XMLNode& node)
 
 AudioRegion::~AudioRegion ()
 {
+	if (_playlist) {
+		for (SourceList::const_iterator i = sources.begin(); i != sources.end(); ++i) {
+			(*i)->remove_playlist (_playlist);
+		}
+	}
+
 	notify_callbacks ();
 	GoingAway (); /* EMIT SIGNAL */
 }
@@ -1145,8 +1151,6 @@ AudioRegion::exportme (Session& session, AudioExportSpecification& spec)
 boost::shared_ptr<Region>
 AudioRegion::get_parent()
 {
-	boost::shared_ptr<Region> r;
-
 	if (_playlist) {
 		boost::shared_ptr<AudioRegion> ar;
 		boost::shared_ptr<AudioRegion> grrr2 = boost::dynamic_pointer_cast<AudioRegion> (shared_from_this());
@@ -1156,7 +1160,7 @@ AudioRegion::get_parent()
 		}
 	}
 	
-	return r;
+	return boost::shared_ptr<Region>();
 }
 
 void
@@ -1305,6 +1309,37 @@ AudioRegion::source_offset_changed ()
 	} 
 }
 
+void
+AudioRegion::set_playlist (Playlist* pl)
+{
+	if (pl == _playlist) {
+		return;
+	}
+
+	Playlist* old_playlist = _playlist;
+
+	Region::set_playlist (pl);
+
+	if (pl) {
+		if (old_playlist) {
+			for (SourceList::const_iterator i = sources.begin(); i != sources.end(); ++i) {
+				(*i)->remove_playlist (old_playlist);	
+				(*i)->add_playlist (_playlist);
+			}
+		} else {
+			for (SourceList::const_iterator i = sources.begin(); i != sources.end(); ++i) {
+				(*i)->add_playlist (_playlist);
+			}
+		}
+	} else {
+		if (old_playlist) {
+			for (SourceList::const_iterator i = sources.begin(); i != sources.end(); ++i) {
+				(*i)->remove_playlist (old_playlist);
+			}
+		}
+	}
+}
+
 extern "C" {
 
 	int region_read_peaks_from_c (void *arg, uint32_t npeaks, uint32_t start, uint32_t cnt, intptr_t data, uint32_t n_chan, double samples_per_unit) 
diff --git a/libs/ardour/diskstream.cc b/libs/ardour/diskstream.cc
index 9e83c5e21a..7b3db9aab4 100644
--- a/libs/ardour/diskstream.cc
+++ b/libs/ardour/diskstream.cc
@@ -392,14 +392,14 @@ Diskstream::set_name (string str)
 }
 
 void
-Diskstream::set_destructive (bool yn)
+Diskstream::remove_region_from_last_capture (boost::weak_ptr<Region> wregion)
 {
-	if (yn != destructive()) {
-		reset_write_sources (true, true);
-		if (yn) {
-			_flags |= Destructive;
-		} else {
-			_flags &= ~Destructive;
-		}
+	boost::shared_ptr<Region> region (wregion.lock());
+
+	if (!region) {
+		return;
 	}
+	
+	_last_capture_regions.remove (region);
 }
+
diff --git a/libs/ardour/playlist.cc b/libs/ardour/playlist.cc
index 713558f15e..a06fe2b5fd 100644
--- a/libs/ardour/playlist.cc
+++ b/libs/ardour/playlist.cc
@@ -85,10 +85,8 @@ Playlist::Playlist (Session& sess, const XMLNode& node, bool hide)
 {
 	init (hide);
 	_name = "unnamed"; /* reset by set_state */
-	
-	if (set_state (node)) {
-		throw failed_constructor();
-	}
+
+	/* derived class calls set_state() */
 }
 
 Playlist::Playlist (const Playlist& other, string namestr, bool hide)
@@ -257,11 +255,19 @@ Playlist::Playlist (Playlist& pl)
 
 Playlist::~Playlist ()
 {
+	{ 
+		RegionLock rl (this);
+
+		for (set<boost::shared_ptr<Region> >::iterator i = all_regions.begin(); i != all_regions.end(); ++i) {
+			(*i)->set_playlist (0);
+		}
+	}
+
 	/* GoingAway must be emitted by derived classes */
 }
 
 void
-Playlist::set_name (const string& str)
+Playlist::set_name (string str)
 {
 	/* in a typical situation, a playlist is being used
 	   by one diskstream and also is referenced by the
@@ -1442,13 +1448,21 @@ Playlist::state (bool full_state)
 bool
 Playlist::empty() const
 {
+	RegionLock rlock (const_cast<Playlist *>(this), false);
 	return regions.empty();
 }
 
+uint32_t
+Playlist::n_regions() const
+{
+	RegionLock rlock (const_cast<Playlist *>(this), false);
+	return regions.size();
+}
+
 nframes_t
 Playlist::get_maximum_extent () const
 {
-	RegionLock rlock (const_cast<Playlist *>(this));
+	RegionLock rlock (const_cast<Playlist *>(this), false);
 	return _get_maximum_extent ();
 }
 
@@ -1475,7 +1489,7 @@ Playlist::bump_name (string name, Session &session)
 
 	do {
 		newname = Playlist::bump_name_once (newname);
-	} while (session.playlist_by_name(newname)!=NULL);
+	} while (session.playlist_by_name (newname)!=NULL);
 
 	return newname;
 }
diff --git a/libs/ardour/region_factory.cc b/libs/ardour/region_factory.cc
index 313bb31f2a..5bcbdb8b80 100644
--- a/libs/ardour/region_factory.cc
+++ b/libs/ardour/region_factory.cc
@@ -93,8 +93,7 @@ RegionFactory::create (Session& session, XMLNode& node, bool yn)
 boost::shared_ptr<Region> 
 RegionFactory::create (SourceList& srcs, nframes_t start, nframes_t length, const string& name, layer_t layer, Region::Flag flags, bool announce)
 {
-	AudioRegion* ar = new AudioRegion (srcs, start, length, name, layer, flags);
-	boost::shared_ptr<AudioRegion> arp (ar);
+	boost::shared_ptr<AudioRegion> arp (new AudioRegion (srcs, start, length, name, layer, flags));
 	boost::shared_ptr<Region> ret (boost::static_pointer_cast<Region> (arp));
 	if (announce) {
 		CheckNewRegion (ret);
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index b2705c2cbd..a4def58bb4 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -2535,7 +2535,7 @@ Session::remove_region (boost::weak_ptr<Region> weak_region)
 	set_dirty();
 
 	if (removed) {
-		 AudioRegionRemoved(ar); /* EMIT SIGNAL */
+		AudioRegionRemoved (ar); /* EMIT SIGNAL */
 	}
 }
 
@@ -2571,32 +2571,38 @@ Session::find_equivalent_playlist_regions (boost::shared_ptr<Region> region, vec
 int
 Session::destroy_region (boost::shared_ptr<Region> region)
 {
-	boost::shared_ptr<AudioRegion> aregion;
-
-	if ((aregion = boost::dynamic_pointer_cast<AudioRegion> (region)) == 0) {
-		return 0;
-	}
-	
-	if (aregion->playlist()) {
-		aregion->playlist()->destroy_region (region);
-	}
-
 	vector<boost::shared_ptr<Source> > srcs;
-	
-	for (uint32_t n = 0; n < aregion->n_channels(); ++n) {
-		srcs.push_back (aregion->source (n));
+		
+	{
+		boost::shared_ptr<AudioRegion> aregion;
+		
+		if ((aregion = boost::dynamic_pointer_cast<AudioRegion> (region)) == 0) {
+			return 0;
+		}
+		
+		if (aregion->playlist()) {
+			aregion->playlist()->destroy_region (region);
+		}
+		
+		for (uint32_t n = 0; n < aregion->n_channels(); ++n) {
+			srcs.push_back (aregion->source (n));
+		}
 	}
 
+	region->drop_references ();
+
 	for (vector<boost::shared_ptr<Source> >::iterator i = srcs.begin(); i != srcs.end(); ++i) {
-		
-		if ((*i).use_count() == 1) {
-			boost::shared_ptr<AudioFileSource> afs = boost::dynamic_pointer_cast<AudioFileSource>(*i);
 
+		if (!(*i)->used()) {
+			boost::shared_ptr<AudioFileSource> afs = boost::dynamic_pointer_cast<AudioFileSource>(*i);
+			
 			if (afs) {
 				(afs)->mark_for_remove ();
 			}
 			
 			(*i)->drop_references ();
+			
+			cerr << "source was not used by any playlist\n";
 		}
 	}
 
@@ -2989,6 +2995,20 @@ Session::add_playlist (Playlist* playlist)
 }
 
 void
+Session::get_playlists (vector<Playlist*>& s)
+{
+	{ 
+		Glib::Mutex::Lock lm (playlist_lock);
+		for (PlaylistList::iterator i = playlists.begin(); i != playlists.end(); ++i) {
+			s.push_back (*i);
+		}
+		for (PlaylistList::iterator i = unused_playlists.begin(); i != unused_playlists.end(); ++i) {
+			s.push_back (*i);
+		}
+	}
+}
+
+void
 Session::track_playlist (Playlist* pl, bool inuse)
 {
 	PlaylistList::iterator x;
diff --git a/libs/ardour/session_state.cc b/libs/ardour/session_state.cc
index 763f8b9c01..f80c9e9a82 100644
--- a/libs/ardour/session_state.cc
+++ b/libs/ardour/session_state.cc
@@ -520,7 +520,6 @@ Session::create (bool& new_session, string* mix_template, nframes_t initial_leng
 	_state_of_the_state = Clean;
 
 	if (save_state (_current_snapshot_name)) {
-		save_history (_current_snapshot_name);
 		return -1;
 	}
 
@@ -2456,6 +2455,8 @@ Session::cleanup_sources (Session::cleanup_report& rep)
 		   capture files.
 		*/
 
+		cerr << "checking out source " << i->second->name() << " use_count = " << i->second.use_count() << endl;
+
 		if (i->second.use_count() == 1 && i->second->length() > 0) {
 			dead_sources.push_back (i->second);
 
diff --git a/libs/ardour/sndfilesource.cc b/libs/ardour/sndfilesource.cc
index 3c3798c8ab..4b9c7ff33b 100644
--- a/libs/ardour/sndfilesource.cc
+++ b/libs/ardour/sndfilesource.cc
@@ -212,7 +212,7 @@ SndFileSource::init (string idstr)
 	_capture_end = false;
 	file_pos = 0;
 
-	if (destructive()) {
+	if (destructive()) {	
 		xfade_buf = new Sample[xfade_frames];
 		timeline_position = header_position_offset;
 	}
@@ -680,11 +680,15 @@ SndFileSource::set_destructive (bool yn)
 {
 	if (yn) {
 		_flags = Flag (_flags | Destructive);
+		if (!xfade_buf) {
+			xfade_buf = new Sample[xfade_frames];
+		}
 		clear_capture_marks ();
 		timeline_position = header_position_offset;
 	} else {
 		_flags = Flag (_flags & ~Destructive);
 		timeline_position = 0;
+		/* leave xfade buf alone in case we need it again later */
 	}
 
 	return true;
diff --git a/libs/ardour/source.cc b/libs/ardour/source.cc
index 7ade8a8573..74ca0afcd4 100644
--- a/libs/ardour/source.cc
+++ b/libs/ardour/source.cc
@@ -34,6 +34,7 @@
 #include <pbd/pthread_utils.h>
 
 #include <ardour/source.h>
+#include <ardour/playlist.h>
 
 #include "i18n.h"
 
@@ -47,12 +48,14 @@ Source::Source (Session& s, string name)
 {
 	_name = name;
 	_timestamp = 0;
+	_in_use = 0;
 }
 
 Source::Source (Session& s, const XMLNode& node) 
 	: _session (s)
 {
 	_timestamp = 0;
+	_in_use = 0;
 
 	if (set_state (node)) {
 		throw failed_constructor();
@@ -106,3 +109,24 @@ Source::set_state (const XMLNode& node)
 	return 0;
 }
 
+void
+Source::add_playlist (Playlist* pl)
+{
+	_playlists.insert (pl);
+}
+
+void
+Source::remove_playlist (Playlist* pl)
+{
+	std::set<Playlist*>::iterator x;
+
+	if ((x = _playlists.find (pl)) != _playlists.end()) {
+		_playlists.erase (x);
+	}
+}
+
+uint32_t
+Source::used () const
+{
+	return _playlists.size();
+}
diff --git a/libs/ardour/track.cc b/libs/ardour/track.cc
index 2c3d7c9151..95e21e6735 100644
--- a/libs/ardour/track.cc
+++ b/libs/ardour/track.cc
@@ -183,18 +183,6 @@ Track::set_record_enable (bool yn, void *src)
 	_rec_enable_control.Changed ();
 }
 
-void
-Track::set_mode (TrackMode m)
-{
-	if (_diskstream) {
-		if (_mode != m) {
-			_mode = m;
-			_diskstream->set_destructive (m == Destructive);
-			ModeChanged();
-		}
-	}
-}
-
 int
 Track::set_name (string str, void *src)
 {
diff --git a/libs/gtkmm2ext/barcontroller.cc b/libs/gtkmm2ext/barcontroller.cc
index eefe6ca843..734c4b77e2 100644
--- a/libs/gtkmm2ext/barcontroller.cc
+++ b/libs/gtkmm2ext/barcontroller.cc
@@ -423,6 +423,7 @@ BarController::switch_to_spinner ()
 	remove ();
 	add (spinner);
 	spinner.show ();
+	spinner.select_region (0, spinner.get_text_length());
 	spinner.grab_focus ();
 
 	switching = false;