From da96d2c21ed81a29f8a43295c866e7b2a068c704 Mon Sep 17 00:00:00 2001
From: Christopher Snowhill <kode54@gmail.com>
Date: Fri, 17 Sep 2021 19:09:34 -0700
Subject: [PATCH] Core Audio Output: Add a check that should prevent it from
 attempting to output data through the callback during or after destruction

---
 Audio/Output/OutputCoreAudio.h | 2 ++
 Audio/Output/OutputCoreAudio.m | 9 +++++++++
 2 files changed, 11 insertions(+)

diff --git a/Audio/Output/OutputCoreAudio.h b/Audio/Output/OutputCoreAudio.h
index 636845cb5..6c283dbcb 100644
--- a/Audio/Output/OutputCoreAudio.h
+++ b/Audio/Output/OutputCoreAudio.h
@@ -17,6 +17,8 @@
 
 @interface OutputCoreAudio : NSObject {
 	OutputNode * outputController;
+    
+    BOOL stopping;
 	
     AudioDeviceID outputDeviceID;
 	AudioUnit outputUnit;
diff --git a/Audio/Output/OutputCoreAudio.m b/Audio/Output/OutputCoreAudio.m
index 8787e4d07..fcb71560c 100644
--- a/Audio/Output/OutputCoreAudio.m
+++ b/Audio/Output/OutputCoreAudio.m
@@ -34,6 +34,13 @@ static OSStatus Sound_Renderer(void *inRefCon,  AudioUnitRenderActionFlags *ioAc
 	void *readPointer = ioData->mBuffers[0].mData;
 	
 	int amountToRead, amountRead;
+    
+    if (output->stopping == YES)
+    {
+        // *shrug* At least this will stop it from trying to emit data post-shutdown
+        ioData->mBuffers[0].mDataByteSize = 0;
+        return eofErr;
+    }
 
 	if ([output->outputController shouldContinue] == NO)
 	{
@@ -384,6 +391,7 @@ static OSStatus Sound_Renderer(void *inRefCon,  AudioUnitRenderActionFlags *ioAc
                                size);
 	
 	//setup render callbacks
+    stopping = NO;
 	renderCallback.inputProc = Sound_Renderer;
 	renderCallback.inputProcRefCon = (__bridge void * _Nullable)(self);
 	
@@ -413,6 +421,7 @@ static OSStatus Sound_Renderer(void *inRefCon,  AudioUnitRenderActionFlags *ioAc
 {
 	if (outputUnit)
 	{
+        stopping = YES;
         AudioOutputUnitStop(outputUnit);
 		AudioUnitUninitialize (outputUnit);
 		AudioComponentInstanceDispose(outputUnit);