From fb1f94767deb95f5636ae6bc5d0f55e2da26b0da Mon Sep 17 00:00:00 2001
From: reuk <reuk@users.noreply.github.com>
Date: Tue, 15 Feb 2022 13:40:03 +0000
Subject: [PATCH] AU Host:  Improve allocation checks

If the block size changes from block to block, then it's possible for
inputBuffer to be smaller than buffer, but for buffer to be smaller than
the initially-allocated size of inputBuffer.
---
 .../format_types/juce_AudioUnitPluginFormat.mm        | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/modules/juce_audio_processors/format_types/juce_AudioUnitPluginFormat.mm b/modules/juce_audio_processors/format_types/juce_AudioUnitPluginFormat.mm
index e6fdacfeb0..8389dd6c65 100644
--- a/modules/juce_audio_processors/format_types/juce_AudioUnitPluginFormat.mm
+++ b/modules/juce_audio_processors/format_types/juce_AudioUnitPluginFormat.mm
@@ -1101,8 +1101,9 @@ public:
             inMapping .setUpMapping (audioUnit, true);
             outMapping.setUpMapping (audioUnit, false);
 
-            inputBuffer.setSize (jmax (getTotalNumInputChannels(), getTotalNumOutputChannels()),
-                                 estimatedSamplesPerBlock);
+            preparedChannels = jmax (getTotalNumInputChannels(), getTotalNumOutputChannels());
+            preparedSamples  = estimatedSamplesPerBlock;
+            inputBuffer.setSize (preparedChannels, preparedSamples);
         }
     }
 
@@ -1130,8 +1131,8 @@ public:
     void processAudio (AudioBuffer<float>& buffer, MidiBuffer& midiMessages, bool processBlockBypassedCalled)
     {
         // If these are hit, we might allocate in the process block!
-        jassert (buffer.getNumChannels() <= inputBuffer.getNumChannels());
-        jassert (buffer.getNumSamples()  <= inputBuffer.getNumSamples());
+        jassert (buffer.getNumChannels() <= preparedChannels);
+        jassert (buffer.getNumSamples()  <= preparedSamples);
         // Copy the input buffer to guard against the case where a bus has more output channels
         // than input channels, so rendering the output for that bus might stamp over the input
         // to the following bus.
@@ -1724,7 +1725,7 @@ private:
     AudioBuffer<float> inputBuffer;
     Array<Array<AudioChannelSet>> supportedInLayouts, supportedOutLayouts;
 
-    int numChannelInfos;
+    int numChannelInfos, preparedChannels = 0, preparedSamples = 0;
     HeapBlock<AUChannelInfo> channelInfos;
 
     AudioUnit audioUnit;