opnmidi_midiplay.cpp: Fixed crash on active notes overflow

Author: Wohlstand

src/opnmidi_midiplay.cpp

@@ -466,6 +466,9 @@ bool OPNMIDIplay::realTime_NoteOn(uint8_t channel, uint8_t note, uint8_t velocit
     if(isBlankNote)
     {
         // Don't even try to play the blank instrument! But, insert the dummy note.
+        if(midiChan.activenotes.size() >= midiChan.activenotes.capacity())
+            return false; // Overflow!
+
         MIDIchannel::notes_iterator i = midiChan.ensure_create_activenote(note);
         MIDIchannel::NoteInfo &dummy = i->value;
         dummy.isBlank = true;
@@ -547,6 +550,9 @@ bool OPNMIDIplay::realTime_NoteOn(uint8_t channel, uint8_t note, uint8_t velocit
         velocity = static_cast<uint8_t>(std::floor(static_cast<float>(velocity) * 0.8f));
 
     // Allocate active note for MIDI channel
+    if(midiChan.activenotes.size() >= midiChan.activenotes.capacity())
+        return false; // Overflow!
+
     MIDIchannel::notes_iterator ir = midiChan.ensure_create_activenote(note);
     MIDIchannel::NoteInfo &ni = ir->value;
     ni.vol     = velocity;