From f499f4cfd2e98ee67d8267aea76a71bf8f47af68 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Wed, 31 Dec 2014 03:12:57 +0100
Subject: [PATCH] don't take temporary copy of MIDI sequence

fixes potential boost shared_ptr double free.
---
 libs/backends/alsa/alsa_audiobackend.cc   | 8 ++++----
 libs/backends/alsa/alsa_audiobackend.h    | 2 +-
 libs/backends/dummy/dummy_audiobackend.cc | 8 ++++----
 libs/backends/dummy/dummy_audiobackend.h  | 4 ++--
 4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/libs/backends/alsa/alsa_audiobackend.cc b/libs/backends/alsa/alsa_audiobackend.cc
index 3ccc97ec94..8bf8efe61d 100644
--- a/libs/backends/alsa/alsa_audiobackend.cc
+++ b/libs/backends/alsa/alsa_audiobackend.cc
@@ -1467,10 +1467,10 @@ AlsaAudioBackend::main_process_thread ()
 				i = 0;
 				for (std::vector<AlsaPort*>::const_iterator it = _system_midi_out.begin (); it != _system_midi_out.end (); ++it, ++i) {
 					assert (_rmidi_out.size() > i);
-					const AlsaMidiBuffer src = static_cast<const AlsaMidiPort*>(*it)->const_buffer();
+					const AlsaMidiBuffer * src = static_cast<const AlsaMidiPort*>(*it)->const_buffer();
 					AlsaMidiOut *rm = _rmidi_out.at(i);
 					rm->sync_time (clock1);
-					for (AlsaMidiBuffer::const_iterator mit = src.begin (); mit != src.end (); ++mit) {
+					for (AlsaMidiBuffer::const_iterator mit = src->begin (); mit != src->end (); ++mit) {
 						rm->send_event ((*mit)->timestamp(), (*mit)->data(), (*mit)->size());
 					}
 				}
@@ -1826,8 +1826,8 @@ void* AlsaMidiPort::get_buffer (pframes_t /* nframes */)
 		for (std::vector<AlsaPort*>::const_iterator i = get_connections ().begin ();
 				i != get_connections ().end ();
 				++i) {
-			const AlsaMidiBuffer src = static_cast<const AlsaMidiPort*>(*i)->const_buffer ();
-			for (AlsaMidiBuffer::const_iterator it = src.begin (); it != src.end (); ++it) {
+			const AlsaMidiBuffer * src = static_cast<const AlsaMidiPort*>(*i)->const_buffer ();
+			for (AlsaMidiBuffer::const_iterator it = src->begin (); it != src->end (); ++it) {
 				(_buffer[_bufperiod]).push_back (boost::shared_ptr<AlsaMidiEvent>(new AlsaMidiEvent (**it)));
 			}
 		}
diff --git a/libs/backends/alsa/alsa_audiobackend.h b/libs/backends/alsa/alsa_audiobackend.h
index f9123875e6..3daae85b21 100644
--- a/libs/backends/alsa/alsa_audiobackend.h
+++ b/libs/backends/alsa/alsa_audiobackend.h
@@ -142,7 +142,7 @@ class AlsaMidiPort : public AlsaPort {
 		DataType type () const { return DataType::MIDI; };
 
 		void* get_buffer (pframes_t nframes);
-		const AlsaMidiBuffer const_buffer () const { return _buffer[_bufperiod]; }
+		const AlsaMidiBuffer * const_buffer () const { return & _buffer[_bufperiod]; }
 
 		void next_period() { if (_n_periods > 1) { get_buffer(0); _bufperiod = (_bufperiod + 1) % _n_periods; } }
 		void set_n_periods(int n) { if (n > 0 && n < 3) { _n_periods = n; } }
diff --git a/libs/backends/dummy/dummy_audiobackend.cc b/libs/backends/dummy/dummy_audiobackend.cc
index bd46a59cd0..087d652b9c 100644
--- a/libs/backends/dummy/dummy_audiobackend.cc
+++ b/libs/backends/dummy/dummy_audiobackend.cc
@@ -1769,10 +1769,10 @@ struct MidiEventSorter {
 	}
 };
 
-void DummyMidiPort::set_loopback (const DummyMidiBuffer src)
+void DummyMidiPort::set_loopback (DummyMidiBuffer const * const src)
 {
 	_loopback.clear ();
-	for (DummyMidiBuffer::const_iterator it = src.begin (); it != src.end (); ++it) {
+	for (DummyMidiBuffer::const_iterator it = src->begin (); it != src->end (); ++it) {
 		_loopback.push_back (boost::shared_ptr<DummyMidiEvent>(new DummyMidiEvent (**it)));
 	}
 }
@@ -1838,8 +1838,8 @@ void* DummyMidiPort::get_buffer (pframes_t n_samples)
 			if (source->is_physical() && source->is_terminal()) {
 				source->get_buffer(n_samples); // generate signal.
 			}
-			const DummyMidiBuffer src = static_cast<const DummyMidiPort*>(*i)->const_buffer ();
-			for (DummyMidiBuffer::const_iterator it = src.begin (); it != src.end (); ++it) {
+			const DummyMidiBuffer *src = source->const_buffer ();
+			for (DummyMidiBuffer::const_iterator it = src->begin (); it != src->end (); ++it) {
 				_buffer.push_back (boost::shared_ptr<DummyMidiEvent>(new DummyMidiEvent (**it)));
 			}
 		}
diff --git a/libs/backends/dummy/dummy_audiobackend.h b/libs/backends/dummy/dummy_audiobackend.h
index c7faf16896..56929d939c 100644
--- a/libs/backends/dummy/dummy_audiobackend.h
+++ b/libs/backends/dummy/dummy_audiobackend.h
@@ -193,10 +193,10 @@ class DummyMidiPort : public DummyPort {
 		DataType type () const { return DataType::MIDI; };
 
 		void* get_buffer (pframes_t nframes);
-		const DummyMidiBuffer const_buffer () const { return _buffer; }
+		const DummyMidiBuffer * const_buffer () const { return &_buffer; }
 
 		void setup_generator (int, float const);
-		void set_loopback (const DummyMidiBuffer src);
+		void set_loopback (DummyMidiBuffer const * const src);
 
 	private:
 		DummyMidiBuffer _buffer;