midway snapshot of work done on managing Region & Source lifetimes correctly. may fix missing MIDI file bug ; save empty playlists because they may be referred to by the history file ; undo commands auto-delete when objects they refer to die (currently not commands built from XML deserialization); Sources now know how many regions are using them for something, meaning that we know if we can delete the files holding any data for the source

git-svn-id: svn://localhost/ardour2/branches/3.0@7291 d708f5d6-7413-0410-9779-e7cbd77b26cf

34 files changed, 307 insertions, 214 deletions

diff --git a/libs/ardour/ardour/diskstream.h b/libs/ardour/ardour/diskstream.h
index c089a39736..d0d2bcbc36 100644
--- a/libs/ardour/ardour/diskstream.h
+++ b/libs/ardour/ardour/diskstream.h
@@ -45,7 +45,7 @@ namespace ARDOUR {
 class IO;
 class Playlist;
 class Processor;
-class Region;
+class Source;
 class Session;
 class Track;
 class Location;	
@@ -134,12 +134,10 @@ class Diskstream : public SessionObject, public PublicDiskstream
 
 	int set_loop (Location *loc);
 
-	std::list<boost::shared_ptr<Region> >& last_capture_regions () { return _last_capture_regions; }
+	std::list<boost::shared_ptr<Source> >& last_capture_sources () { return _last_capture_sources; }
 
 	void handle_input_change (IOChange, void *src);
 
-	void remove_region_from_last_capture (boost::weak_ptr<Region> wregion);
-
 	void move_processor_automation (boost::weak_ptr<Processor>,
 			std::list<Evoral::RangeMove<framepos_t> > const &);
 
@@ -228,7 +226,7 @@ class Diskstream : public SessionObject, public PublicDiskstream
 
 	virtual bool realtime_set_speed (double, bool global_change);
 
-	std::list<boost::shared_ptr<Region> > _last_capture_regions;
+	std::list<boost::shared_ptr<Source> > _last_capture_sources;
 
 	virtual int use_pending_capture_data (XMLNode& node) = 0;
 
diff --git a/libs/ardour/ardour/playlist.h b/libs/ardour/ardour/playlist.h
index 4b42fc0bd6..7afc074b4d 100644
--- a/libs/ardour/ardour/playlist.h
+++ b/libs/ardour/ardour/playlist.h
@@ -65,7 +65,8 @@ class RegionListProperty : public PBD::SequenceProperty<std::list<boost::shared_
         RegionListProperty (Playlist&);
 
         boost::shared_ptr<Region> lookup_id (const PBD::ID& id);
-        void diff (PBD::PropertyList& undo, PBD::PropertyList& redo) const;
+        void diff (PBD::PropertyList& undo, PBD::PropertyList& redo, Command*) const;
+        bool involves (boost::shared_ptr<Region>);
 
   private:
         friend class Playlist;
diff --git a/libs/ardour/ardour/public_diskstream.h b/libs/ardour/ardour/public_diskstream.h
index c31e88a79b..9e25cb24c6 100755
--- a/libs/ardour/ardour/public_diskstream.h
+++ b/libs/ardour/ardour/public_diskstream.h
@@ -23,7 +23,7 @@
 namespace ARDOUR {
 
 class Playlist;
-class Region;
+class Source;
 class Location;
 
 /** Public interface to a Diskstream */	
@@ -34,7 +34,7 @@ public:
 	virtual boost::shared_ptr<Playlist> playlist () = 0;
 	virtual void monitor_input (bool) = 0;
 	virtual bool destructive () const = 0;
-	virtual std::list<boost::shared_ptr<Region> > & last_capture_regions () = 0;
+	virtual std::list<boost::shared_ptr<Source> > & last_capture_sources () = 0;
 	virtual void set_capture_offset () = 0;
 	virtual void reset_write_sources (bool, bool force = false) = 0;
 	virtual float playback_buffer_load () const = 0;
diff --git a/libs/ardour/ardour/region.h b/libs/ardour/ardour/region.h
index 2cf9bab97b..a30bb8660c 100644
--- a/libs/ardour/ardour/region.h
+++ b/libs/ardour/ardour/region.h
@@ -270,6 +270,8 @@ class Region
 		return _pending_explicit_relayer;
 	}
 
+        void drop_sources ();
+
   protected:
 	friend class RegionFactory;
 
diff --git a/libs/ardour/ardour/region_factory.h b/libs/ardour/ardour/region_factory.h
index c9f387f172..459699d810 100644
--- a/libs/ardour/ardour/region_factory.h
+++ b/libs/ardour/ardour/region_factory.h
@@ -21,6 +21,7 @@
 #define __ardour_region_factory_h__
 
 #include <map>
+#include <set>
 #include <glibmm/thread.h>
 
 #include "pbd/id.h"
@@ -78,7 +79,10 @@ class RegionFactory {
 	/** create a region with specified sources @param srcs and XML state */
 	static boost::shared_ptr<Region> create (SourceList& srcs, const XMLNode&);
 
+        static void get_regions_using_source (boost::shared_ptr<Source>, std::set<boost::shared_ptr<Region> >& );
+
 	static void map_remove (boost::shared_ptr<Region>);
+	static void map_remove_with_equivalents (boost::shared_ptr<Region>);
         static void delete_all_regions ();
         static const RegionMap& regions() { return region_map; }
         static uint32_t nregions ();
diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index f7692e09cb..bca65c88e4 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -512,8 +512,7 @@ class Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionLi
 	int  cleanup_sources (CleanupReport&);
 	int  cleanup_trash_sources (CleanupReport&);
 
-	int destroy_region (boost::shared_ptr<Region>);
-	int destroy_regions (std::list<boost::shared_ptr<Region> >);
+	int destroy_sources (std::list<boost::shared_ptr<Source> >);
 
 	int remove_last_capture ();
 
diff --git a/libs/ardour/ardour/session_playlists.h b/libs/ardour/ardour/session_playlists.h
index d654595d60..1c83a312a5 100644
--- a/libs/ardour/ardour/session_playlists.h
+++ b/libs/ardour/ardour/session_playlists.h
@@ -53,6 +53,7 @@ public:
 	template<class T> void foreach (T *obj, void (T::*func)(boost::shared_ptr<Playlist>));
 	void get (std::vector<boost::shared_ptr<Playlist> >&);
 	void unassigned (std::list<boost::shared_ptr<Playlist> > & list);
+        void destroy_region (boost::shared_ptr<Region>);
 
 private:
 	friend class Session;
@@ -69,7 +70,7 @@ private:
 	int load (Session &, const XMLNode&);
 	int load_unused (Session &, const XMLNode&);
 	boost::shared_ptr<Playlist> XMLPlaylistFactory (Session &, const XMLNode&);
-
+        
 	mutable Glib::Mutex lock;
 	typedef std::set<boost::shared_ptr<Playlist> > List;
 	List playlists;
diff --git a/libs/ardour/ardour/source.h b/libs/ardour/ardour/source.h
index bf92e5a6e4..16a762eb94 100644
--- a/libs/ardour/ardour/source.h
+++ b/libs/ardour/ardour/source.h
@@ -23,6 +23,8 @@
 #include <string>
 #include <set>
 
+#include <glib.h>
+
 #include <boost/utility.hpp>
 #include "pbd/statefuldestructible.h"
 
@@ -102,6 +104,15 @@ class Source : public SessionObject
 	Glib::Mutex& mutex()       { return _lock; }
 	Flag         flags() const { return _flags; }
 
+        void inc_use_count () { g_atomic_int_inc (&_use_count); }
+        void dec_use_count () { 
+                gint oldval = g_atomic_int_exchange_and_add (&_use_count, -1);
+                assert (oldval > 0);
+        }
+
+        int  use_count() const { return g_atomic_int_get (&_use_count); }
+        bool used() const { return use_count() > 0; }
+
   protected:
 	DataType            _type;
 	Flag                _flags;
@@ -111,6 +122,7 @@ class Source : public SessionObject
 	mutable Glib::Mutex _lock;
 	mutable Glib::Mutex _analysis_lock;
 	Glib::Mutex         _playlist_lock;
+        gint                _use_count; /* atomic */
 
   private:
 	void fix_writable_flags ();
diff --git a/libs/ardour/ardour/track.h b/libs/ardour/ardour/track.h
index ac948f12df..d72d29e563 100644
--- a/libs/ardour/ardour/track.h
+++ b/libs/ardour/ardour/track.h
@@ -29,6 +29,7 @@ namespace ARDOUR {
 class Session;
 class Playlist;
 class RouteGroup;
+class Source;
 class Region;
 class Diskstream;
 
@@ -100,7 +101,7 @@ class Track : public Route, public PublicDiskstream
 	boost::shared_ptr<Playlist> playlist ();
 	void monitor_input (bool);
 	bool destructive () const;
-	std::list<boost::shared_ptr<Region> > & last_capture_regions ();
+	std::list<boost::shared_ptr<Source> > & last_capture_sources ();
 	void set_capture_offset ();
 	void reset_write_sources (bool, bool force = false);
 	float playback_buffer_load () const;
diff --git a/libs/ardour/audio_diskstream.cc b/libs/ardour/audio_diskstream.cc
index b3204c38b6..ae80690b81 100644
--- a/libs/ardour/audio_diskstream.cc
+++ b/libs/ardour/audio_diskstream.cc
@@ -480,8 +480,8 @@ AudioDiskstream::process (nframes_t transport_frame, nframes_t nframes, bool can
                 was_recording = true;
         }
 
-	if (can_record && !_last_capture_regions.empty()) {
-		_last_capture_regions.clear ();
+	if (can_record && !_last_capture_sources.empty()) {
+		_last_capture_sources.clear ();
 	}
 
 	if (rec_nframes) {
@@ -1447,7 +1447,6 @@ AudioDiskstream::transport_stopped_wallclock (struct tm& when, time_t twhen, boo
 			plist.add (Properties::start, c->front()->write_source->last_capture_start_frame());
 			plist.add (Properties::length, total_capture);
 			plist.add (Properties::name, whole_file_region_name);
-
 			boost::shared_ptr<Region> rx (RegionFactory::create (srcs, plist));
 			rx->set_automatic (true);
 			rx->set_whole_file (true);
@@ -1462,7 +1461,7 @@ AudioDiskstream::transport_stopped_wallclock (struct tm& when, time_t twhen, boo
 			/* XXX what now? */
 		}
 
-		_last_capture_regions.push_back (region);
+		_last_capture_sources.insert (_last_capture_sources.end(), srcs.begin(), srcs.end());
 
 		// cerr << _name << ": there are " << capture_info.size() << " capture_info records\n";
 
@@ -1494,10 +1493,6 @@ AudioDiskstream::transport_stopped_wallclock (struct tm& when, time_t twhen, boo
 				continue; /* XXX is this OK? */
 			}
 
-			region->DropReferences.connect_same_thread (*this, boost::bind (&Diskstream::remove_region_from_last_capture, this, boost::weak_ptr<Region>(region)));
-
-			_last_capture_regions.push_back (region);
-
 			i_am_the_modifier++;
 			_playlist->add_region (region, (*ci)->start, 1, non_layered());
 			i_am_the_modifier--;
@@ -1914,6 +1909,8 @@ AudioDiskstream::reset_write_sources (bool mark_write_complete, bool /*force*/)
 	boost::shared_ptr<ChannelList> c = channels.reader();
 	uint32_t n;
 
+        cerr << name() << " resetting write sources, recrodable " << recordable() << " chans = " << c->size() << endl;
+
 	if (!_session.writable() || !recordable()) {
 		return;
 	}
@@ -2356,6 +2353,7 @@ void
 AudioDiskstream::ChannelInfo::resize_capture (nframes_t capture_bufsize)
 {
         delete capture_buf;
+
 	capture_buf = new RingBufferNPT<Sample> (capture_bufsize);
 	memset (capture_buf->buffer(), 0, sizeof (Sample) * capture_buf->bufsize());
 }
diff --git a/libs/ardour/audio_playlist.cc b/libs/ardour/audio_playlist.cc
index bd09af4e1f..6a27541bcd 100644
--- a/libs/ardour/audio_playlist.cc
+++ b/libs/ardour/audio_playlist.cc
@@ -663,17 +663,15 @@ bool
 AudioPlaylist::destroy_region (boost::shared_ptr<Region> region)
 {
 	boost::shared_ptr<AudioRegion> r = boost::dynamic_pointer_cast<AudioRegion> (region);
+
+        if (!r) {
+                return false;
+        }
+
 	bool changed = false;
 	Crossfades::iterator c, ctmp;
 	set<boost::shared_ptr<Crossfade> > unique_xfades;
 
-	if (r == 0) {
-		fatal << _("programming error: non-audio Region passed to remove_overlap in audio playlist")
-		      << endmsg;
-		/*NOTREACHED*/
-		return false;
-	}
-
 	{
 		RegionLock rlock (this);
 
diff --git a/libs/ardour/audioregion.cc b/libs/ardour/audioregion.cc
index 0ef79b7018..80f8baef0e 100644
--- a/libs/ardour/audioregion.cc
+++ b/libs/ardour/audioregion.cc
@@ -263,6 +263,9 @@ AudioRegion::connect_to_header_position_offset_changed ()
 
 	for (SourceList::const_iterator i = _sources.begin(); i != _sources.end(); ++i) {
 
+                /* connect only once to HeaderPositionOffsetChanged, even if sources are replicated
+                 */
+
 		if (unique_srcs.find (*i) == unique_srcs.end ()) {
 			unique_srcs.insert (*i);
 			boost::shared_ptr<AudioFileSource> afs = boost::dynamic_pointer_cast<AudioFileSource> (*i);
@@ -520,24 +523,8 @@ AudioRegion::state (bool full)
 	XMLNode& node (Region::state (full));
 	XMLNode *child;
 	char buf[64];
-	char buf2[64];
 	LocaleGuard lg (X_("POSIX"));
 
-
-	// XXX these should move into Region
-
-	for (uint32_t n=0; n < _sources.size(); ++n) {
-		snprintf (buf2, sizeof(buf2), "source-%d", n);
-		_sources[n]->id().print (buf, sizeof (buf));
-		node.add_property (buf2, buf);
-	}
-
-	for (uint32_t n=0; n < _master_sources.size(); ++n) {
-		snprintf (buf2, sizeof(buf2), "master-source-%d", n);
-		_master_sources[n]->id().print (buf, sizeof (buf));
-		node.add_property (buf2, buf);
-	}
-
 	snprintf (buf, sizeof (buf), "%u", (uint32_t) _sources.size());
 	node.add_property ("channels", buf);
 
@@ -571,10 +558,6 @@ AudioRegion::state (bool full)
 		child->add_property ("default", "yes");
 	}
 
-	if (full && _extra_xml) {
-		node.add_child_copy (*_extra_xml);
-	}
-
 	return node;
 }
 
diff --git a/libs/ardour/diskstream.cc b/libs/ardour/diskstream.cc
index 40a2714dc0..5dd9a3b306 100644
--- a/libs/ardour/diskstream.cc
+++ b/libs/ardour/diskstream.cc
@@ -436,18 +436,6 @@ Diskstream::set_name (const string& str)
 }
 
 void
-Diskstream::remove_region_from_last_capture (boost::weak_ptr<Region> wregion)
-{
-	boost::shared_ptr<Region> region (wregion.lock());
-
-	if (!region) {
-		return;
-	}
-
-	_last_capture_regions.remove (region);
-}
-
-void
 Diskstream::playlist_ranges_moved (list< Evoral::RangeMove<framepos_t> > const & movements_frames)
 {
 	if (!_track || Config->get_automation_follows_regions () == false) {
diff --git a/libs/ardour/midi_diskstream.cc b/libs/ardour/midi_diskstream.cc
index fa2cdce014..444e4d3788 100644
--- a/libs/ardour/midi_diskstream.cc
+++ b/libs/ardour/midi_diskstream.cc
@@ -524,8 +524,8 @@ MidiDiskstream::process (nframes_t transport_frame, nframes_t nframes, bool can_
 	}
 
 
-	if (can_record && !_last_capture_regions.empty()) {
-		_last_capture_regions.clear ();
+	if (can_record && !_last_capture_sources.empty()) {
+		_last_capture_sources.clear ();
 	}
 
 	if (nominally_recording || rec_nframes) {
@@ -975,9 +975,7 @@ MidiDiskstream::transport_stopped_wallclock (struct tm& /*when*/, time_t /*twhen
 			/* XXX what now? */
 		}
 
-		_last_capture_regions.push_back (region);
-
-		// cerr << _name << ": there are " << capture_info.size() << " capture_info records\n";
+		_last_capture_sources.insert (_last_capture_sources.end(), srcs.begin(), srcs.end());
 
 		_playlist->clear_history ();
 		_playlist->freeze ();
@@ -1007,10 +1005,6 @@ MidiDiskstream::transport_stopped_wallclock (struct tm& /*when*/, time_t /*twhen
 				continue; /* XXX is this OK? */
 			}
 
-			region->DropReferences.connect_same_thread (*this, boost::bind (&Diskstream::remove_region_from_last_capture, this, boost::weak_ptr<Region>(region)));
-
-			_last_capture_regions.push_back (region);
-
 			// cerr << "add new region, buffer position = " << buffer_position << " @ " << (*ci)->start << endl;
 
 			i_am_the_modifier++;
@@ -1312,6 +1306,8 @@ MidiDiskstream::set_state (const XMLNode& node, int /*version*/)
 int
 MidiDiskstream::use_new_write_source (uint32_t n)
 {
+        cerr << name() << " use new write source for n = " << n << " recordable ? " << recordable() << endl;
+
 	if (!recordable()) {
 		return 1;
 	}
diff --git a/libs/ardour/midi_playlist.cc b/libs/ardour/midi_playlist.cc
index 152735de85..6f5dee979a 100644
--- a/libs/ardour/midi_playlist.cc
+++ b/libs/ardour/midi_playlist.cc
@@ -359,15 +359,13 @@ bool
 MidiPlaylist::destroy_region (boost::shared_ptr<Region> region)
 {
 	boost::shared_ptr<MidiRegion> r = boost::dynamic_pointer_cast<MidiRegion> (region);
-	bool changed = false;
 
-	if (r == 0) {
-		PBD::fatal << _("programming error: non-midi Region passed to remove_overlap in midi playlist")
-		<< endmsg;
-		/*NOTREACHED*/
+	if (!r) {
 		return false;
 	}
 
+	bool changed = false;
+
 	{
 		RegionLock rlock (this);
 		RegionList::iterator i;
diff --git a/libs/ardour/midi_region.cc b/libs/ardour/midi_region.cc
index fe03e64f72..abb3191463 100644
--- a/libs/ardour/midi_region.cc
+++ b/libs/ardour/midi_region.cc
@@ -193,30 +193,7 @@ MidiRegion::_read_at (const SourceList& /*srcs*/, Evoral::EventSink<nframes_t>&
 XMLNode&
 MidiRegion::state (bool full)
 {
-	XMLNode& node (Region::state (full));
-	char buf[64];
-	char buf2[64];
-	LocaleGuard lg (X_("POSIX"));
-
-	// XXX these should move into Region
-
-	for (uint32_t n=0; n < _sources.size(); ++n) {
-		snprintf (buf2, sizeof(buf2), "source-%d", n);
-		_sources[n]->id().print (buf, sizeof(buf));
-		node.add_property (buf2, buf);
-	}
-
-	for (uint32_t n=0; n < _master_sources.size(); ++n) {
-		snprintf (buf2, sizeof(buf2), "master-source-%d", n);
-		_master_sources[n]->id().print (buf, sizeof (buf));
-		node.add_property (buf2, buf);
-	}
-
-	if (full && _extra_xml) {
-		node.add_child_copy (*_extra_xml);
-	}
-
-	return node;
+	return Region::state (full);
 }
 
 int
diff --git a/libs/ardour/playlist.cc b/libs/ardour/playlist.cc
index 0526d48b11..f07cd645f1 100644
--- a/libs/ardour/playlist.cc
+++ b/libs/ardour/playlist.cc
@@ -134,7 +134,7 @@ RegionListProperty::copy_for_history () const
 }
 
 void 
-RegionListProperty::diff (PropertyList& undo, PropertyList& redo) const
+RegionListProperty::diff (PropertyList& undo, PropertyList& redo, Command* cmd) const
 {
         if (changed()) {
 		/* list of the removed/added regions since clear_history() was last called */
@@ -144,6 +144,18 @@ RegionListProperty::diff (PropertyList& undo, PropertyList& redo) const
                 RegionListProperty* b = copy_for_history ();
                 b->invert_changes ();
 
+                if (cmd) {
+                        /* whenever one of the regions emits DropReferences, make sure
+                           that the Destructible we've been told to notify hears about
+                           it. the Destructible is likely to be the Command being built
+                           with this diff().
+                        */
+                        
+                        for (set<boost::shared_ptr<Region> >::iterator i = a->change().added.begin(); i != a->change().added.end(); ++i) {
+                                (*i)->DropReferences.connect_same_thread (*cmd, boost::bind (&Destructible::drop_references, cmd));
+                        }
+                }
+
                 undo.add (b);
                 redo.add (a);
         }
diff --git a/libs/ardour/region.cc b/libs/ardour/region.cc
index 2589f94f81..e620319633 100644
--- a/libs/ardour/region.cc
+++ b/libs/ardour/region.cc
@@ -415,6 +415,7 @@ Region::Region (boost::shared_ptr<const Region> other)
 Region::~Region ()
 {
 	DEBUG_TRACE (DEBUG::Destruction, string_compose ("Region %1 destructor @ %2\n", _name, this));
+        drop_sources ();
 }
 
 void
@@ -1126,10 +1127,12 @@ Region::set_layer (layer_t l)
 }
 
 XMLNode&
-Region::state (bool /*full_state*/)
+Region::state (bool full)
 {
 	XMLNode *node = new XMLNode ("Region");
 	char buf[64];
+	char buf2[64];
+	LocaleGuard lg (X_("POSIX"));
 	const char* fe = NULL;
 
 	add_properties (*node);
@@ -1164,6 +1167,22 @@ Region::state (bool /*full_state*/)
 		node->add_property ("bbt-position", str.str());
 	}
 
+	for (uint32_t n=0; n < _sources.size(); ++n) {
+		snprintf (buf2, sizeof(buf2), "source-%d", n);
+		_sources[n]->id().print (buf, sizeof(buf));
+		node->add_property (buf2, buf);
+	}
+
+	for (uint32_t n=0; n < _master_sources.size(); ++n) {
+		snprintf (buf2, sizeof(buf2), "master-source-%d", n);
+		_master_sources[n]->id().print (buf, sizeof (buf));
+		node->add_property (buf2, buf);
+	}
+
+	if (full && _extra_xml) {
+		node->add_child_copy (*_extra_xml);
+	}
+
 	return *node;
 }
 
@@ -1237,11 +1256,6 @@ Region::_set_state (const XMLNode& node, int version, PropertyChange& what_chang
 	}
 
 	if (send) {
-		cerr << _name << ": final change to be sent: ";
-		for (PropertyChange::iterator i = what_changed.begin(); i != what_changed.end(); ++i) {
-			cerr << g_quark_to_string ((GQuark) *i) << ' ';
-		}
-		cerr << endl;
 		send_change (what_changed);
 	}
 	
@@ -1335,7 +1349,7 @@ Region::region_list_equivalent (boost::shared_ptr<const Region> other) const
 void
 Region::source_deleted (boost::weak_ptr<Source>)
 {
-	_sources.clear ();
+        drop_sources ();
 
 	if (!_session.deletion_in_progress()) {
 		/* this is a very special case: at least one of the region's
@@ -1366,8 +1380,16 @@ Region::master_source_names ()
 void
 Region::set_master_sources (const SourceList& srcs)
 {
+        for (SourceList::const_iterator i = _master_sources.begin (); i != _master_sources.end(); ++i) {
+                (*i)->dec_use_count ();
+        }
+
 	_master_sources = srcs;
 	assert (_sources.size() == _master_sources.size());
+
+        for (SourceList::const_iterator i = _master_sources.begin (); i != _master_sources.end(); ++i) {
+                (*i)->inc_use_count ();
+        }
 }
 
 bool
@@ -1408,6 +1430,7 @@ Region::uses_source (boost::shared_ptr<const Source> source) const
 sframes_t
 Region::source_length(uint32_t n) const
 {
+        assert (n < _sources.size());
 	return _sources[n]->length(_position - _start);
 }
 
@@ -1420,7 +1443,7 @@ Region::verify_length (framecnt_t len)
 
 	framecnt_t maxlen = 0;
 
-	for (uint32_t n=0; n < _sources.size(); ++n) {
+	for (uint32_t n = 0; n < _sources.size(); ++n) {
 		maxlen = max (maxlen, source_length(n) - _start);
 	}
 
@@ -1438,7 +1461,7 @@ Region::verify_start_and_length (framepos_t new_start, framecnt_t& new_length)
 
 	framecnt_t maxlen = 0;
 
-	for (uint32_t n=0; n < _sources.size(); ++n) {
+	for (uint32_t n = 0; n < _sources.size(); ++n) {
 		maxlen = max (maxlen, source_length(n) - new_start);
 	}
 
@@ -1454,7 +1477,7 @@ Region::verify_start (framepos_t pos)
 		return true;
 	}
 
-	for (uint32_t n=0; n < _sources.size(); ++n) {
+	for (uint32_t n = 0; n < _sources.size(); ++n) {
 		if (pos > source_length(n) - _length) {
 			return false;
 		}
@@ -1469,7 +1492,7 @@ Region::verify_start_mutable (framepos_t& new_start)
 		return true;
 	}
 
-	for (uint32_t n=0; n < _sources.size(); ++n) {
+	for (uint32_t n = 0; n < _sources.size(); ++n) {
 		if (new_start > source_length(n) - _length) {
 			new_start = source_length(n) - _length;
 		}
@@ -1508,6 +1531,21 @@ Region::invalidate_transients ()
 	_transients.clear ();
 }
 
+void
+Region::drop_sources ()
+{
+        for (SourceList::const_iterator i = _sources.begin (); i != _sources.end(); ++i) {
+                (*i)->dec_use_count ();
+        }
+
+	_sources.clear ();
+
+        for (SourceList::const_iterator i = _master_sources.begin (); i != _master_sources.end(); ++i) {
+                (*i)->dec_use_count ();
+        }
+
+        _master_sources.clear ();
+}
 
 void
 Region::use_sources (SourceList const & s)
@@ -1515,16 +1553,19 @@ Region::use_sources (SourceList const & s)
 	set<boost::shared_ptr<Source> > unique_srcs;
 
 	for (SourceList::const_iterator i = s.begin (); i != s.end(); ++i) {
-		_sources.push_back (*i);
-		(*i)->DropReferences.connect_same_thread (*this, boost::bind (&Region::source_deleted, this, boost::weak_ptr<Source>(*i)));
-		unique_srcs.insert (*i);
-	}
 
-	for (SourceList::const_iterator i = s.begin (); i != s.end(); ++i) {
+		_sources.push_back (*i);
+                (*i)->inc_use_count ();
 		_master_sources.push_back (*i);
-		if (unique_srcs.find (*i) == unique_srcs.end()) {
-			(*i)->DropReferences.connect_same_thread (*this, boost::bind (&Region::source_deleted, this, boost::weak_ptr<Source>(*i)));
-		}
+                (*i)->inc_use_count ();
+
+                /* connect only once to DropReferences, even if sources are replicated
+                 */
+
+		if (unique_srcs.find (*i) == unique_srcs.end ()) {
+			unique_srcs.insert (*i);
+                        (*i)->DropReferences.connect_same_thread (*this, boost::bind (&Region::source_deleted, this, boost::weak_ptr<Source>(*i)));
+                }
 	}
 }
 
diff --git a/libs/ardour/region_factory.cc b/libs/ardour/region_factory.cc
index 5a4b129710..65649ad8f7 100644
--- a/libs/ardour/region_factory.cc
+++ b/libs/ardour/region_factory.cc
@@ -73,6 +73,7 @@ RegionFactory::create (boost::shared_ptr<const Region> region)
 	}
 
 	if (ret) {
+                cerr << "Pure copy constructor region " << ret << " named " << ret->name() << endl;
 		map_add (ret);
 
 		/* pure copy constructor - no property list */
@@ -124,6 +125,7 @@ RegionFactory::create (boost::shared_ptr<Region> region, frameoffset_t offset, b
 
 	if (ret) {
 		ret->set_properties (plist);
+                cerr << "Partial copy constructor region\n";
 		map_add (ret);
 
 		if (announce) {
@@ -163,6 +165,7 @@ RegionFactory::create (boost::shared_ptr<Region> region, const SourceList& srcs,
 	if (ret) {
 
 		ret->set_properties (plist);
+                cerr << "New sources copy constructor region\n";
 		map_add (ret);
 
 		if (announce) {
@@ -208,6 +211,7 @@ RegionFactory::create (const SourceList& srcs, const PropertyList& plist, bool a
 	if (ret) {
 
 		ret->set_properties (plist);
+                cerr << "de-novo constructor region " << ret << " named " << ret->name() << endl;
 		map_add (ret);
 
 		if (announce) {
@@ -281,6 +285,8 @@ RegionFactory::map_add (boost::shared_ptr<Region> r)
 		boost::bind (&RegionFactory::region_changed, _1, boost::weak_ptr<Region> (r))
 		);
 
+        cerr << "Added region with ID = " << r->id() << " named " << r->name() << endl;
+
 	update_region_name_map (r);
 }
 
@@ -292,7 +298,32 @@ RegionFactory::map_remove (boost::shared_ptr<Region> r)
 
         if (i != region_map.end()) {
                 region_map.erase (i);
+                cerr << "Removed region with ID = " << r->id() << " named " << r->name() << endl;;
         }
+
+}
+
+void
+RegionFactory::map_remove_with_equivalents (boost::shared_ptr<Region> r)
+{
+        Glib::Mutex::Lock lm (region_map_lock);
+
+        for (RegionMap::iterator i = region_map.begin(); i != region_map.end(); ) {
+                RegionMap::iterator tmp = i;
+                ++tmp;
+
+                if (r->region_list_equivalent (i->second)) {
+                        cerr << "Removed equivalent region " << i->second->name() << '/' << i->first << endl;
+                        region_map.erase (i);
+                } else if (r == i->second) {
+                        cerr << "Removed actual region " << i->second->name() << '/' << i->first << endl;
+                        region_map.erase (i);
+                } 
+
+                i = tmp;
+        }
+
+
 }
 
 boost::shared_ptr<Region>
@@ -487,3 +518,15 @@ RegionFactory::new_region_name (string old)
 	error << string_compose (_("cannot create new name for region \"%1\""), old) << endmsg;
 	return old;
 }
+
+void 
+RegionFactory::get_regions_using_source (boost::shared_ptr<Source> s, std::set<boost::shared_ptr<Region> >& r)
+{
+        Glib::Mutex::Lock lm (region_map_lock);
+
+        for (RegionMap::iterator i = region_map.begin(); i != region_map.end(); ++i) {
+                if (i->second->uses_source (s)) {
+                        r.insert (i->second);
+                }
+        }
+}
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index 3d5430d259..91b1e2a0f9 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -1484,6 +1484,7 @@ Session::new_midi_track (TrackMode mode, RouteGroup* route_group, uint32_t how_m
 			auto_connect_route (track, existing_inputs, existing_outputs);
 
 			track->non_realtime_input_change();
+
 			if (route_group) {
 				route_group->add (track);
 			}
@@ -2483,46 +2484,58 @@ Session::find_whole_file_parent (boost::shared_ptr<Region const> child) const
 }
 
 int
-Session::destroy_region (boost::shared_ptr<Region> region)
+Session::destroy_sources (list<boost::shared_ptr<Source> > srcs)
 {
-	vector<boost::shared_ptr<Source> > srcs;
-
-	{
-		if (region->playlist()) {
-			region->playlist()->destroy_region (region);
-		}
+        set<boost::shared_ptr<Region> > relevant_regions;
 
-		for (uint32_t n = 0; n < region->n_channels(); ++n) {
-			srcs.push_back (region->source (n));
-		}
+	for (list<boost::shared_ptr<Source> >::iterator s = srcs.begin(); s != srcs.end(); ++s) {
+                RegionFactory::get_regions_using_source (*s, relevant_regions);
 	}
 
-	region->drop_references ();
+        cerr << "There are " << relevant_regions.size() << " using " << srcs.size() << " sources" << endl;
+
+        for (set<boost::shared_ptr<Region> >::iterator r = relevant_regions.begin(); r != relevant_regions.end(); ) {
+                set<boost::shared_ptr<Region> >::iterator tmp;
+
+                tmp = r;
+                ++tmp;
+
+                cerr << "Cleanup " << (*r)->name() << " UC = " << (*r).use_count() << endl;
 
-	for (vector<boost::shared_ptr<Source> >::iterator i = srcs.begin(); i != srcs.end(); ++i) {
+                playlists->destroy_region (*r);
+                RegionFactory::map_remove (*r);
 
-                (*i)->mark_for_remove ();
-                (*i)->drop_references ();
+                (*r)->drop_sources ();
+                (*r)->drop_references ();
+
+                cerr << "\tdone UC = " << (*r).use_count() << endl;
+
+                relevant_regions.erase (r);
+
+                r = tmp;
+        }
+
+	for (list<boost::shared_ptr<Source> >::iterator s = srcs.begin(); s != srcs.end(); ) {
                 
-                cerr << "source was not used by any playlist\n";
-	}
+                {
+                        Glib::Mutex::Lock ls (source_lock);
+                        /* remove from the main source list */
+                        sources.erase ((*s)->id());
+                }
 
-	return 0;
-}
+                (*s)->mark_for_remove ();
+                (*s)->drop_references ();
+
+                s = srcs.erase (s);
+        }
 
-int
-Session::destroy_regions (list<boost::shared_ptr<Region> > regions)
-{
-	for (list<boost::shared_ptr<Region> >::iterator i = regions.begin(); i != regions.end(); ++i) {
-		destroy_region (*i);
-	}
 	return 0;
 }
 
 int
 Session::remove_last_capture ()
 {
-	list<boost::shared_ptr<Region> > r;
+	list<boost::shared_ptr<Source> > srcs;
 
 	boost::shared_ptr<RouteList> rl = routes.reader ();
 	for (RouteList::iterator i = rl->begin(); i != rl->end(); ++i) {
@@ -2531,15 +2544,15 @@ Session::remove_last_capture ()
 			continue;
 		}
 		
-		list<boost::shared_ptr<Region> >& l = tr->last_capture_regions();
+		list<boost::shared_ptr<Source> >& l = tr->last_capture_sources();
 
 		if (!l.empty()) {
-			r.insert (r.end(), l.begin(), l.end());
+			srcs.insert (srcs.end(), l.begin(), l.end());
 			l.clear ();
 		}
 	}
 
-	destroy_regions (r);
+	destroy_sources (srcs);
 
 	save_state (_current_snapshot_name);
 
@@ -2563,16 +2576,19 @@ Session::add_source (boost::shared_ptr<Source> source)
 	}
 
 	if (result.second) {
-		set_dirty();
-	}
 
-	boost::shared_ptr<AudioFileSource> afs;
+                /* yay, new source */
 
-	if ((afs = boost::dynamic_pointer_cast<AudioFileSource>(source)) != 0) {
-		if (Config->get_auto_analyse_audio()) {
-			Analyser::queue_source_for_analysis (source, false);
-		}
-	}
+		set_dirty();
+
+                boost::shared_ptr<AudioFileSource> afs;
+                
+                if ((afs = boost::dynamic_pointer_cast<AudioFileSource>(source)) != 0) {
+                        if (Config->get_auto_analyse_audio()) {
+                                Analyser::queue_source_for_analysis (source, false);
+                        }
+                }
+        }
 }
 
 void
diff --git a/libs/ardour/session_playlists.cc b/libs/ardour/session_playlists.cc
index 2f8ae9a8f0..38c6744d06 100644
--- a/libs/ardour/session_playlists.cc
+++ b/libs/ardour/session_playlists.cc
@@ -220,6 +220,21 @@ SessionPlaylists::get (vector<boost::shared_ptr<Playlist> >& s)
 }
 
 void
+SessionPlaylists::destroy_region (boost::shared_ptr<Region> r)
+{
+	Glib::Mutex::Lock lm (lock);
+
+	for (List::iterator i = playlists.begin(); i != playlists.end(); ++i) {
+                (*i)->destroy_region (r);
+	}
+	
+	for (List::iterator i = unused_playlists.begin(); i != unused_playlists.end(); ++i) {
+                (*i)->destroy_region (r);
+	}
+}
+
+
+void
 SessionPlaylists::find_equivalent_playlist_regions (boost::shared_ptr<Region> region, vector<boost::shared_ptr<Region> >& result)
 {
 	for (List::iterator i = playlists.begin(); i != playlists.end(); ++i)
@@ -262,14 +277,12 @@ SessionPlaylists::add_state (XMLNode* node, bool full_state)
 	XMLNode* child = node->add_child ("Playlists");
 	for (List::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());
-				}
-			}
-		}
+                        if (full_state) {
+                                child->add_child_nocopy ((*i)->get_state());
+                        } else {
+                                child->add_child_nocopy ((*i)->get_template());
+                        }
+                }
 	}
 
 	child = node->add_child ("UnusedPlaylists");
diff --git a/libs/ardour/session_state.cc b/libs/ardour/session_state.cc
index a490bb10c9..0f8583a822 100644
--- a/libs/ardour/session_state.cc
+++ b/libs/ardour/session_state.cc
@@ -1040,13 +1040,18 @@ Session::state(bool full_state)
 
 		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... */
+			/* Don't save information about non-destructive file sources that are empty
+                           and unused by any regions.
+                        */
 
-			boost::shared_ptr<AudioFileSource> fs;
-			if ((fs = boost::dynamic_pointer_cast<AudioFileSource> (siter->second)) != 0) {
+                        cerr << "Source " << siter->second->name() << " has UC = " << siter->second->used() 
+                             << " length = " <<  siter->second->length (0)
+                             << endl;
+
+			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->length(fs->timeline_position()) == 0 && !fs->used()) {
 						continue;
 					}
 				}
diff --git a/libs/ardour/source.cc b/libs/ardour/source.cc
index 5ec9631e40..55ce9f8bef 100644
--- a/libs/ardour/source.cc
+++ b/libs/ardour/source.cc
@@ -52,6 +52,7 @@ Source::Source (Session& s, DataType type, const string& name, Flag flags)
 	, _type(type)
 	, _flags(flags)
 	, _timeline_position(0)
+        , _use_count (0)
 {
 	_analysed = false;
 	_timestamp = 0;
@@ -63,6 +64,7 @@ Source::Source (Session& s, const XMLNode& node)
 	, _type(DataType::AUDIO)
 	, _flags (Flag (Writable|CanRename))
 	, _timeline_position(0)
+        , _use_count (0)
 {
 	_timestamp = 0;
 	_analysed = false;
diff --git a/libs/ardour/track.cc b/libs/ardour/track.cc
index ad4c765867..b2079e0a2e 100644
--- a/libs/ardour/track.cc
+++ b/libs/ardour/track.cc
@@ -425,10 +425,10 @@ Track::destructive () const
 	return _diskstream->destructive ();
 }
 
-list<boost::shared_ptr<Region> > &
-Track::last_capture_regions ()
+list<boost::shared_ptr<Source> > &
+Track::last_capture_sources ()
 {
-	return _diskstream->last_capture_regions ();
+	return _diskstream->last_capture_sources ();
 }
 
 void
diff --git a/libs/evoral/src/SMF.cpp b/libs/evoral/src/SMF.cpp
index b8705afbf0..cf838455ce 100644
--- a/libs/evoral/src/SMF.cpp
+++ b/libs/evoral/src/SMF.cpp
@@ -275,6 +275,16 @@ SMF::begin_write()
 void
 SMF::end_write() THROW_FILE_ERROR
 {
+#if 0
+        /* don't create empty MIDI files 
+         */
+
+        smf_rewind (_smf); // smf_save() would have done this anyway
+        if (smf_peek_next_event (_smf) == 0) {
+                return;
+        }
+#endif
+
 	PBD::StdioFileDescriptor d (_file_path, "w+");
 	FILE* f = d.allocate ();
 	if (f == 0) {
diff --git a/libs/pbd/pbd/command.h b/libs/pbd/pbd/command.h
index 5a7290bc89..c6c3c8d3fd 100644
--- a/libs/pbd/pbd/command.h
+++ b/libs/pbd/pbd/command.h
@@ -22,10 +22,12 @@
 #ifndef __lib_pbd_command_h__
 #define __lib_pbd_command_h__
 
+#include <string>
+
+#include "pbd/signals.h"
 #include "pbd/statefuldestructible.h"
-#include <boost/utility.hpp>
 
-class Command : public PBD::StatefulDestructible, public boost::noncopyable
+class Command : public PBD::StatefulDestructible, public PBD::ScopedConnectionList
 {
 public:
 	virtual ~Command() { /* NOTE: derived classes must call drop_references() */ }
@@ -34,7 +36,7 @@ public:
 	
 	void set_name (const std::string& str) { _name = str; }
 	const std::string& name() const { return _name; }
-	
+
 	virtual void undo() = 0;
 	virtual void redo() { (*this)(); }
 	
diff --git a/libs/pbd/pbd/properties.h b/libs/pbd/pbd/properties.h
index 784282ee9c..1914344db9 100644
--- a/libs/pbd/pbd/properties.h
+++ b/libs/pbd/pbd/properties.h
@@ -165,7 +165,7 @@ public:
 		: PropertyTemplate<T> (q, v)
 	{}
         
-        void diff (PropertyList& undo, PropertyList& redo) const {
+        void diff (PropertyList& undo, PropertyList& redo, Command* /*ignored*/) const {
                 if (this->_have_old) {
                         undo.add (new Property<T> (this->property_id(), this->_old));
                         redo.add (new Property<T> (this->property_id(), this->_current));
@@ -227,7 +227,7 @@ public:
 		: PropertyTemplate<std::string> (q, v)
 	{}
 
-        void diff (PropertyList& before, PropertyList& after) const {
+        void diff (PropertyList& before, PropertyList& after, Command* /*ignored*/) const {
                 if (this->_have_old) {
                         before.add (new Property<std::string> (PropertyDescriptor<std::string> (this->property_id()), this->_old));
                         after.add (new Property<std::string> (PropertyDescriptor<std::string> (this->property_id()), this->_current));
diff --git a/libs/pbd/pbd/property_basics.h b/libs/pbd/pbd/property_basics.h
index 5e94abdfc3..2dea20e251 100644
--- a/libs/pbd/pbd/property_basics.h
+++ b/libs/pbd/pbd/property_basics.h
@@ -25,6 +25,8 @@
 
 #include "pbd/xml++.h"
 
+class Command;
+
 namespace PBD {
 
 class PropertyList;
@@ -83,7 +85,7 @@ public:
 	{}
 
 	virtual ~PropertyBase () {}
-
+        
 	/** Forget about any old value for this state */
 	virtual void clear_history () = 0;
 
@@ -97,7 +99,7 @@ public:
 	 *  the last call to clear_history, and one that allows redo
 	 *  of those changes.
 	 */
-	virtual void diff (PropertyList& undo, PropertyList& redo) const = 0;
+	virtual void diff (PropertyList& undo, PropertyList& redo, Command*) const = 0;
         
         virtual PropertyBase* maybe_clone_self_if_found_in_history_node (const XMLNode&) const { return 0; }
 
diff --git a/libs/pbd/pbd/stateful.h b/libs/pbd/pbd/stateful.h
index 4352e88201..1272a735f9 100644
--- a/libs/pbd/pbd/stateful.h
+++ b/libs/pbd/pbd/stateful.h
@@ -67,7 +67,7 @@ class Stateful {
         /* history management */
 
 	void clear_history ();
-        void diff (PropertyList&, PropertyList&) const;
+        void diff (PropertyList&, PropertyList&, Command*) const;
         bool changed() const;
 
         /* create a property list from an XMLNode
diff --git a/libs/pbd/pbd/stateful_diff_command.h b/libs/pbd/pbd/stateful_diff_command.h
index 21245f029a..25cdfbba12 100644
--- a/libs/pbd/pbd/stateful_diff_command.h
+++ b/libs/pbd/pbd/stateful_diff_command.h
@@ -27,7 +27,7 @@
 namespace PBD
 {
 
-class Stateful;	
+class StatefulDestructible;	
 class PropertyList;
 
 /** A Command which stores its action as the differences between the before and after
@@ -36,13 +36,13 @@ class PropertyList;
 class StatefulDiffCommand : public Command
 {
 public:
-	StatefulDiffCommand (boost::shared_ptr<Stateful>);
-	StatefulDiffCommand (boost::shared_ptr<Stateful>, XMLNode const &);
+	StatefulDiffCommand (boost::shared_ptr<StatefulDestructible>);
+	StatefulDiffCommand (boost::shared_ptr<StatefulDestructible>, XMLNode const &);
 	~StatefulDiffCommand ();
 
 	void operator() ();
 	void undo ();
-
+        
 	XMLNode& get_state ();
 
 private:
diff --git a/libs/pbd/pbd/undo.h b/libs/pbd/pbd/undo.h
index 6eb9e00056..fb5152c293 100644
--- a/libs/pbd/pbd/undo.h
+++ b/libs/pbd/pbd/undo.h
@@ -27,12 +27,11 @@
 #include <sigc++/bind.h>
 #include <sys/time.h>
 
-#include "pbd/signals.h"
 #include "pbd/command.h"
 
 typedef sigc::slot<void> UndoAction;
 
-class UndoTransaction : public Command, public PBD::ScopedConnectionList
+class UndoTransaction : public Command
 {
   public:
 	UndoTransaction ();
diff --git a/libs/pbd/stateful.cc b/libs/pbd/stateful.cc
index b486319c4c..1c3d08b3a9 100644
--- a/libs/pbd/stateful.cc
+++ b/libs/pbd/stateful.cc
@@ -167,10 +167,10 @@ Stateful::clear_history ()
 }
 
 void
-Stateful::diff (PropertyList& before, PropertyList& after) const
+Stateful::diff (PropertyList& before, PropertyList& after, Command* cmd) const
 {
 	for (OwnedPropertyList::const_iterator i = _properties->begin(); i != _properties->end(); ++i) {
-		i->second->diff (before, after);
+		i->second->diff (before, after, cmd);
 	}
 }
 
diff --git a/libs/pbd/stateful_diff_command.cc b/libs/pbd/stateful_diff_command.cc
index 635fe4829a..2c58acee14 100644
--- a/libs/pbd/stateful_diff_command.cc
+++ b/libs/pbd/stateful_diff_command.cc
@@ -32,15 +32,21 @@ using namespace PBD;
  *  @param s Stateful object.
  */
 
-StatefulDiffCommand::StatefulDiffCommand (boost::shared_ptr<Stateful> s)
-	: _object (s)
+StatefulDiffCommand::StatefulDiffCommand (boost::shared_ptr<StatefulDestructible> s)
+        : _object (s)
         , _undo (new PropertyList)
         , _redo (new PropertyList)
 {
-        s->diff (*_undo, *_redo);
+        s->diff (*_undo, *_redo, this);
+
+        /* if the stateful object that this command refers to goes away,
+           be sure to notify owners of this command.
+        */
+
+        s->DropReferences.connect_same_thread (*this, boost::bind (&Destructible::drop_references, this));
 }
 
-StatefulDiffCommand::StatefulDiffCommand (boost::shared_ptr<Stateful> s, XMLNode const & n)
+StatefulDiffCommand::StatefulDiffCommand (boost::shared_ptr<StatefulDestructible> s, XMLNode const & n)
 	: _object (s)
         , _undo (0)
         , _redo (0)
@@ -57,10 +63,18 @@ StatefulDiffCommand::StatefulDiffCommand (boost::shared_ptr<Stateful> s, XMLNode
 
         assert (_undo != 0);
         assert (_redo != 0);
+
+        /* if the stateful object that this command refers to goes away,
+           be sure to notify owners of this command.
+        */
+
+        s->DropReferences.connect_same_thread (*this, boost::bind (&Destructible::drop_references, this));
 }
 
 StatefulDiffCommand::~StatefulDiffCommand ()
 {
+        drop_references ();
+
         delete _undo;
         delete _redo;
 }
diff --git a/libs/pbd/undo.cc b/libs/pbd/undo.cc
index a06127926f..120f62c351 100644
--- a/libs/pbd/undo.cc
+++ b/libs/pbd/undo.cc
@@ -39,7 +39,6 @@ UndoTransaction::UndoTransaction ()
 
 UndoTransaction::UndoTransaction (const UndoTransaction& rhs)
 	: Command(rhs._name)
-	, PBD::ScopedConnectionList ()
 	, _clearing(false)
 {
 	clear ();
@@ -77,15 +76,15 @@ UndoTransaction::operator= (const UndoTransaction& rhs)
 }
 
 void
-UndoTransaction::add_command (Command *const action)
+UndoTransaction::add_command (Command *const cmd)
 {
 	/* catch death of command (e.g. caused by death of object to
 	   which it refers. command_death() is a normal static function
 	   so there is no need to manage this connection.
 	 */
 
-	action->DropReferences.connect_same_thread (*this, boost::bind (&command_death, this, action));
-	actions.push_back (action);
+	cmd->DropReferences.connect_same_thread (*this, boost::bind (&command_death, this, cmd));
+	actions.push_back (cmd);
 }
 
 void
@@ -250,9 +249,6 @@ UndoHistory::undo (unsigned int n)
 		return;
 	}
 
-	struct timeval start, end, diff;
-	gettimeofday (&start, 0);
-
 	{
 		UndoRedoSignaller exception_safe_signaller (*this);
 
@@ -265,16 +261,8 @@ UndoHistory::undo (unsigned int n)
 			ut->undo ();
 			RedoList.push_back (ut);
 		}
-		gettimeofday (&end, 0);
-		timersub (&end, &start, &diff);
-		cerr << "Undo-pre-signals took " << diff.tv_sec << '.' << diff.tv_usec << endl;
-
 	}
 
-	gettimeofday (&end, 0);
-	timersub (&end, &start, &diff);
-	cerr << "Undo took " << diff.tv_sec << '.' << diff.tv_usec << endl;
-
 	Changed (); /* EMIT SIGNAL */
 }
 
@@ -285,9 +273,6 @@ UndoHistory::redo (unsigned int n)
 		return;
 	}
 
-	struct timeval start, end, diff;
-	gettimeofday (&start, 0);
-
 	{
 		UndoRedoSignaller exception_safe_signaller (*this);
 		
@@ -300,15 +285,8 @@ UndoHistory::redo (unsigned int n)
 			ut->redo ();
 			UndoList.push_back (ut);
 		}
-		gettimeofday (&end, 0);
-		timersub (&end, &start, &diff);
-		cerr << "Redo-pre-signals took " << diff.tv_sec << '.' << diff.tv_usec << endl;
 	}
 
-	gettimeofday (&end, 0);
-	timersub (&end, &start, &diff);
-	cerr << "Redo took " << diff.tv_sec << '.' << diff.tv_usec << endl;
-
 	Changed (); /* EMIT SIGNAL */
 }