Fix a runtime warning with native MIDI

Signed-off-by: falkTX <falktx@falktx.com>

distrho/src/jackbridge/NativeBridge.hpp

@@ -73,6 +73,7 @@ struct NativeBridge {
    #endif
    #if DISTRHO_PLUGIN_WANT_MIDI_INPUT || DISTRHO_PLUGIN_WANT_MIDI_OUTPUT
     bool midiAvailable;
+    bool midiUsed;
    #endif
    #if DISTRHO_PLUGIN_WANT_MIDI_INPUT
     static constexpr const uint32_t kMaxMIDIInputMessageSize = 3;
@@ -105,6 +106,7 @@ struct NativeBridge {
        #endif
        #if DISTRHO_PLUGIN_WANT_MIDI_INPUT || DISTRHO_PLUGIN_WANT_MIDI_OUTPUT
        , midiAvailable(false)
+       , midiUsed(false)
        #endif
     {
        #if DISTRHO_PLUGIN_NUM_INPUTS+DISTRHO_PLUGIN_NUM_OUTPUTS > 0
@@ -136,8 +138,16 @@ struct NativeBridge {
        #endif
     }
 
+    virtual bool isMIDIEnabled() const
+    {
+       #if DISTRHO_PLUGIN_WANT_MIDI_INPUT || DISTRHO_PLUGIN_WANT_MIDI_OUTPUT
+        return midiUsed;
+       #else
+        return false;
+       #endif
+    }
+
     virtual bool supportsBufferSizeChanges() const { return false; }
-    virtual bool isMIDIEnabled() const { return false; }
     virtual bool requestAudioInput() { return false; }
     virtual bool requestBufferSizeChange(uint32_t) { return false; }
     virtual bool requestMIDI() { return false; }
@@ -238,7 +248,7 @@ struct NativeBridge {
 
         if (audio)
         {
-           #if DISTRHO_PLUGIN_NUM_INPUTS+DISTRHO_PLUGIN_NUM_OUTPUTS > 0
+           #if DISTRHO_PLUGIN_NUM_INPUTS + DISTRHO_PLUGIN_NUM_OUTPUTS > 0
             audioBufferStorage = new float[bufferSize*(DISTRHO_PLUGIN_NUM_INPUTS+DISTRHO_PLUGIN_NUM_OUTPUTS)];
 
             for (uint i=0; i<DISTRHO_PLUGIN_NUM_INPUTS+DISTRHO_PLUGIN_NUM_OUTPUTS; ++i)
@@ -252,6 +262,9 @@ struct NativeBridge {
 
         if (midi)
         {
+           #if DISTRHO_PLUGIN_WANT_MIDI_INPUT || DISTRHO_PLUGIN_WANT_MIDI_OUTPUT
+            midiUsed = true;
+           #endif
            #if DISTRHO_PLUGIN_WANT_MIDI_INPUT
             midiInBufferCurrent.createBuffer(kMaxMIDIInputMessageSize * 512);
             midiInBufferPending.createBuffer(kMaxMIDIInputMessageSize * 512);
@@ -268,12 +281,18 @@ struct NativeBridge {
         delete[] audioBufferStorage;
         audioBufferStorage = nullptr;
        #endif
-       #if DISTRHO_PLUGIN_WANT_MIDI_INPUT
-        midiInBufferCurrent.deleteBuffer();
-        midiInBufferPending.deleteBuffer();
-       #endif
-       #if DISTRHO_PLUGIN_WANT_MIDI_OUTPUT
-        midiOutBuffer.deleteBuffer();
+       #if DISTRHO_PLUGIN_WANT_MIDI_INPUT || DISTRHO_PLUGIN_WANT_MIDI_OUTPUT
+        if (midiUsed)
+        {
+            midiUsed = false;
+           #if DISTRHO_PLUGIN_WANT_MIDI_INPUT
+            midiInBufferCurrent.deleteBuffer();
+            midiInBufferPending.deleteBuffer();
+           #endif
+           #if DISTRHO_PLUGIN_WANT_MIDI_OUTPUT
+            midiOutBuffer.deleteBuffer();
+           #endif
+        }
        #endif
     }