From bc3e330f97d575f2ba36012023f0ea82ed4d4933 Mon Sep 17 00:00:00 2001
From: Tom Poole <thomas.poole@roli.com>
Date: Tue, 25 Jun 2019 13:33:20 +0100
Subject: [PATCH] AUv3:  Fixed a potential crash when producing MIDI from
 plug-ins

---
 .../juce_audio_plugin_client/AU/juce_AUv3_Wrapper.mm | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/modules/juce_audio_plugin_client/AU/juce_AUv3_Wrapper.mm b/modules/juce_audio_plugin_client/AU/juce_AUv3_Wrapper.mm
index 775ad4aefb..56e829d17f 100644
--- a/modules/juce_audio_plugin_client/AU/juce_AUv3_Wrapper.mm
+++ b/modules/juce_audio_plugin_client/AU/juce_AUv3_Wrapper.mm
@@ -1522,12 +1522,14 @@ private:
 
             // send MIDI
            #if JucePlugin_ProducesMidiOutput && JUCE_AUV3_MIDI_OUTPUT_SUPPORTED
-            auto midiOut = [au MIDIOutputEventBlock];
-            MidiMessage msg;
-            int samplePosition;
+            if (auto midiOut = [au MIDIOutputEventBlock])
+            {
+                MidiMessage msg;
+                int samplePosition;
 
-            for (MidiBuffer::Iterator it (midiMessages); it.getNextEvent (msg, samplePosition);)
-                midiOut (samplePosition, 0, msg.getRawDataSize(), msg.getRawData());
+                for (MidiBuffer::Iterator it (midiMessages); it.getNextEvent (msg, samplePosition);)
+                    midiOut (samplePosition, 0, msg.getRawDataSize(), msg.getRawData());
+            }
            #endif
 
             midiMessages.clear();