From 4ebc6ef0b400b8db94635d2220124a642450ce60 Mon Sep 17 00:00:00 2001
From: Tim Mayberry <mojofunk@gmail.com>
Date: Tue, 6 Oct 2015 13:24:53 +1000
Subject: [PATCH] Fix WinMME midi driver shutdown with sysex enabled

midiInReset triggers the sysex callback to tell the application that it has
finished with the buffer. Calling midiInAddBuffer results in an infinite loop
so just return during shutdown.
---
 libs/backends/portaudio/winmmemidi_input_device.cc | 14 ++++++++++++--
 libs/backends/portaudio/winmmemidi_input_device.h  |  1 +
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/libs/backends/portaudio/winmmemidi_input_device.cc b/libs/backends/portaudio/winmmemidi_input_device.cc
index 9fcee83efb..ed8f23b45e 100644
--- a/libs/backends/portaudio/winmmemidi_input_device.cc
+++ b/libs/backends/portaudio/winmmemidi_input_device.cc
@@ -37,6 +37,7 @@ namespace ARDOUR {
 WinMMEMidiInputDevice::WinMMEMidiInputDevice (int index)
 	: m_handle(0)
 	, m_started(false)
+	, m_in_reset(false)
 	, m_midi_buffer(new RingBuffer<uint8_t>(MIDI_BUFFER_SIZE))
 	, m_sysex_buffer(new uint8_t[SYSEX_BUFFER_SIZE])
 {
@@ -92,12 +93,14 @@ WinMMEMidiInputDevice::close (std::string& error_msg)
 	// return error message for first error encountered?
 	bool success = true;
 
+	m_in_reset = true;
 	MMRESULT result = midiInReset (m_handle);
 	if (result != MMSYSERR_NOERROR) {
 		error_msg = get_error_string (result);
 		DEBUG_MIDI (error_msg);
 		success = false;
 	}
+	m_in_reset = false;
 	result = midiInUnprepareHeader (m_handle, &m_sysex_header, sizeof(MIDIHDR));
 	if (result != MMSYSERR_NOERROR) {
 		error_msg = get_error_string (result);
@@ -258,12 +261,19 @@ WinMMEMidiInputDevice::handle_sysex_msg (MIDIHDR* const midi_header,
 
 	uint8_t* data = (uint8_t*)header->lpData;
 
-	if ((data[0] != 0xf0) || (data[byte_count - 1] != 0xf7)) {
-		DEBUG_MIDI (string_compose ("Discarding %1 byte sysex chunk\n", byte_count));
+	DEBUG_MIDI(string_compose("WinMME sysex flags: %1\n", header->dwFlags));
+
+	if (m_in_reset) {
+		DEBUG_MIDI(string_compose("Midi device %1 being reset ignoring sysex msg\n",
+		                          name()));
+		return;
+	} else if ((data[0] != 0xf0) || (data[byte_count - 1] != 0xf7)) {
+		DEBUG_MIDI(string_compose("Discarding %1 byte sysex chunk\n", byte_count));
 	} else {
 		enqueue_midi_msg (data, byte_count, timestamp);
 	}
 
+
 	MMRESULT result = midiInAddBuffer (m_handle, &m_sysex_header, sizeof(MIDIHDR));
 	if (result != MMSYSERR_NOERROR) {
 		DEBUG_MIDI (get_error_string (result));
diff --git a/libs/backends/portaudio/winmmemidi_input_device.h b/libs/backends/portaudio/winmmemidi_input_device.h
index b1a7fb6b88..06b8202f43 100644
--- a/libs/backends/portaudio/winmmemidi_input_device.h
+++ b/libs/backends/portaudio/winmmemidi_input_device.h
@@ -91,6 +91,7 @@ private: // data
 	MIDIHDR m_sysex_header;
 
 	bool m_started;
+	bool m_in_reset;
 
 	std::string m_name;