DSP: Added an assertion to protect against invalid use of ProcessContextNonReplacing

modules/juce_dsp/containers/juce_AudioBlock.h

@@ -151,6 +151,20 @@ public:
     AudioBlock (const AudioBlock& other) noexcept = default;
     AudioBlock& operator= (const AudioBlock& other) noexcept = default;
 
+    //==============================================================================
+    bool operator== (const AudioBlock& other) const noexcept
+    {
+        return std::equal (channels,       channels + numChannels,
+                           other.channels, other.channels + other.numChannels)
+                   && startSample == other.startSample
+                   && numSamples == other.numSamples;
+    }
+
+    bool operator!= (const AudioBlock& other) const noexcept
+    {
+        return ! (*this == other);
+    }
+
     //==============================================================================
     forcedinline size_t getNumSamples() const noexcept           { return numSamples; }
     forcedinline size_t getNumChannels() const noexcept          { return static_cast<size_t> (numChannels); }

modules/juce_dsp/processors/juce_ProcessContext.h

@@ -139,7 +139,12 @@ public:
         Note that the caller must not delete these blocks while they are still in use by this object!
     */
     ProcessContextNonReplacing (const AudioBlockType& input, AudioBlockType& output) noexcept
-        : inputBlock (input), outputBlock (output) {}
+        : inputBlock (input), outputBlock (output)
+    {
+        // If the input and output blocks are the same then you should use
+        // ProcessContextReplacing instead.
+        jassert (input != output);
+    }
 
     ProcessContextNonReplacing (const ProcessContextNonReplacing&) = default;
     ProcessContextNonReplacing (ProcessContextNonReplacing&&) = default;