From 07fafac36e4599738009d49ce1ccac8cfa2a7450 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Mon, 23 Jun 2014 12:16:35 +0200
Subject: [PATCH] don't let enumerated device list strings go out of scope.

---
 libs/backends/alsa/alsa_audiobackend.cc   | 16 ++++++++--------
 libs/backends/alsa/alsa_audiobackend.h    |  3 +++
 libs/backends/dummy/dummy_audiobackend.cc |  8 +++++---
 libs/backends/dummy/dummy_audiobackend.h  |  1 +
 4 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/libs/backends/alsa/alsa_audiobackend.cc b/libs/backends/alsa/alsa_audiobackend.cc
index a61d3a1869..a411916c68 100644
--- a/libs/backends/alsa/alsa_audiobackend.cc
+++ b/libs/backends/alsa/alsa_audiobackend.cc
@@ -39,6 +39,8 @@ using namespace ARDOUR;
 static std::string s_instance_name;
 size_t AlsaAudioBackend::_max_buffer_size = 8192;
 std::vector<std::string> AlsaAudioBackend::_midi_options;
+std::vector<AudioBackend::DeviceStatus> AlsaAudioBackend::_audio_device_status;
+std::vector<AudioBackend::DeviceStatus> AlsaAudioBackend::_midi_device_status;
 
 AlsaAudioBackend::AlsaAudioBackend (AudioEngine& e, AudioBackendInfo& info)
 	: AudioBackend (e, info)
@@ -87,13 +89,13 @@ AlsaAudioBackend::is_realtime () const
 std::vector<AudioBackend::DeviceStatus>
 AlsaAudioBackend::enumerate_devices () const
 {
-	std::vector<AudioBackend::DeviceStatus> s;
+	_audio_device_status.clear();
 	std::map<std::string, std::string> devices;
 	get_alsa_audio_device_names(devices);
 	for (std::map<std::string, std::string>::const_iterator i = devices.begin (); i != devices.end(); ++i) {
-		s.push_back (DeviceStatus (i->first, true));
+		_audio_device_status.push_back (DeviceStatus (i->first, true));
 	}
-	return s;
+	return _audio_device_status;
 }
 
 void
@@ -415,7 +417,7 @@ AlsaAudioBackend::enumerate_midi_options () const
 std::vector<AudioBackend::DeviceStatus>
 AlsaAudioBackend::enumerate_midi_devices () const
 {
-	std::vector<AudioBackend::DeviceStatus> s;
+	_midi_device_status.clear();
 	std::map<std::string, std::string> devices;
 
 	if (_midi_driver_option == _("ALSA raw devices")) {
@@ -423,14 +425,12 @@ AlsaAudioBackend::enumerate_midi_devices () const
 	}
 	else if (_midi_driver_option == _("ALSA sequencer")) {
 		get_alsa_sequencer_names (devices);
-	} else {
-		return s;
 	}
 
 	for (std::map<std::string, std::string>::const_iterator i = devices.begin (); i != devices.end(); ++i) {
-		s.push_back (DeviceStatus (i->first, true));
+		_midi_device_status.push_back (DeviceStatus (i->first, true));
 	}
-	return s;
+	return _midi_device_status;
 }
 
 int
diff --git a/libs/backends/alsa/alsa_audiobackend.h b/libs/backends/alsa/alsa_audiobackend.h
index 089420e78e..6f54ba2f1c 100644
--- a/libs/backends/alsa/alsa_audiobackend.h
+++ b/libs/backends/alsa/alsa_audiobackend.h
@@ -303,6 +303,9 @@ class AlsaAudioBackend : public AudioBackend {
 		bool  _measure_latency;
 
 		static std::vector<std::string> _midi_options;
+		static std::vector<AudioBackend::DeviceStatus> _audio_device_status;
+		static std::vector<AudioBackend::DeviceStatus> _midi_device_status;
+
 		std::string _audio_device;
 		std::string _midi_driver_option;
 
diff --git a/libs/backends/dummy/dummy_audiobackend.cc b/libs/backends/dummy/dummy_audiobackend.cc
index dc53010443..3a969aa479 100644
--- a/libs/backends/dummy/dummy_audiobackend.cc
+++ b/libs/backends/dummy/dummy_audiobackend.cc
@@ -33,6 +33,7 @@ using namespace ARDOUR;
 static std::string s_instance_name;
 size_t DummyAudioBackend::_max_buffer_size = 8192;
 std::vector<std::string> DummyAudioBackend::_midi_options;
+std::vector<AudioBackend::DeviceStatus> DummyAudioBackend::_device_status;
 
 DummyAudioBackend::DummyAudioBackend (AudioEngine& e, AudioBackendInfo& info)
 	: AudioBackend (e, info)
@@ -76,9 +77,10 @@ DummyAudioBackend::is_realtime () const
 std::vector<AudioBackend::DeviceStatus>
 DummyAudioBackend::enumerate_devices () const
 {
-	std::vector<AudioBackend::DeviceStatus> s;
-	s.push_back (DeviceStatus (_("Dummy"), true));
-	return s;
+	if (_device_status.empty()) {
+		_device_status.push_back (DeviceStatus (_("Dummy"), true));
+	}
+	return _device_status;
 }
 
 std::vector<float>
diff --git a/libs/backends/dummy/dummy_audiobackend.h b/libs/backends/dummy/dummy_audiobackend.h
index 638bb9f312..70aec34ecd 100644
--- a/libs/backends/dummy/dummy_audiobackend.h
+++ b/libs/backends/dummy/dummy_audiobackend.h
@@ -293,6 +293,7 @@ class DummyAudioBackend : public AudioBackend {
 	private:
 		std::string _instance_name;
 		static std::vector<std::string> _midi_options;
+		static std::vector<AudioBackend::DeviceStatus> _device_status;
 
 		bool  _running;
 		bool  _freewheeling;