Program: 24022
Project: 24022
Buggy source:
private void synthToFileInternalOnly(final SpeechItem speechItem){
class SynthThread implements Runnable {
    public void run(){
      boolean synthAvailable=false;
      String utteranceId="String_Node_Str";
      Log.i("String_Node_Str","String_Node_Str" + speechItem.mFilename);
      try {
        synthAvailable=synthesizerLock.tryLock();
        if (!synthAvailable) {
          Thread.sleep(100);
          Thread synth=(new Thread(new SynthThread()));
          synth.setPriority(Thread.MIN_PRIORITY);
          synth.start();
          return;
        }
        if (speechItem.mParams != null) {
          String language="String_Node_Str";
          String country="String_Node_Str";
          String variant="String_Node_Str";
          for (int i=0; i < speechItem.mParams.size() - 1; i=i + 2) {
            String param=speechItem.mParams.get(i);
            if (param != null) {
              if (param.equals(TextToSpeech.Engine.TTS_KEY_PARAM_RATE)) {
                setSpeechRate("String_Node_Str",Integer.parseInt(speechItem.mParams.get(i + 1)));
              }
 else               if (param.equals(TextToSpeech.Engine.TTS_KEY_PARAM_LANGUAGE)) {
                language=speechItem.mParams.get(i + 1);
              }
 else               if (param.equals(TextToSpeech.Engine.TTS_KEY_PARAM_COUNTRY)) {
                country=speechItem.mParams.get(i + 1);
              }
 else               if (param.equals(TextToSpeech.Engine.TTS_KEY_PARAM_VARIANT)) {
                variant=speechItem.mParams.get(i + 1);
              }
 else               if (param.equals(TextToSpeech.Engine.TTS_KEY_PARAM_UTTERANCE_ID)) {
                utteranceId=speechItem.mParams.get(i + 1);
              }
            }
          }
          if (language.length() > 0) {
            setLanguage("String_Node_Str",language,country,variant);
          }
        }
        nativeSynth.synthesizeToFile(speechItem.mText,speechItem.mFilename);
      }
 catch (      InterruptedException e) {
        Log.e("String_Node_Str","String_Node_Str");
        e.printStackTrace();
      }
 finally {
        if (synthAvailable) {
          synthesizerLock.unlock();
        }
        if (utteranceId.length() > 0) {
          dispatchUtteranceCompletedCallback(utteranceId,speechItem.mCallingApp);
        }
        mCurrentSpeechItem=null;
        processSpeechQueue();
      }
    }
  }
  Thread synth=(new Thread(new SynthThread()));
  synth.setPriority(Thread.MIN_PRIORITY);
  synth.start();
}

Fixed version (ground truth):
private void synthToFileInternalOnly(final SpeechItem speechItem){
class SynthThread implements Runnable {
    public void run(){
      boolean synthAvailable=false;
      String utteranceId="String_Node_Str";
      Log.i("String_Node_Str","String_Node_Str" + speechItem.mFilename);
      try {
        synthAvailable=synthesizerLock.tryLock();
        if (!synthAvailable) {
          Thread.sleep(100);
          Thread synth=(new Thread(new SynthThread()));
          synth.setPriority(Thread.MIN_PRIORITY);
          synth.start();
          return;
        }
        if (speechItem.mParams != null) {
          String language="String_Node_Str";
          String country="String_Node_Str";
          String variant="String_Node_Str";
          for (int i=0; i < speechItem.mParams.size() - 1; i=i + 2) {
            String param=speechItem.mParams.get(i);
            if (param != null) {
              if (param.equals(TextToSpeech.Engine.TTS_KEY_PARAM_RATE)) {
                setSpeechRate("String_Node_Str",Integer.parseInt(speechItem.mParams.get(i + 1)));
              }
 else               if (param.equals(TextToSpeech.Engine.TTS_KEY_PARAM_LANGUAGE)) {
                language=speechItem.mParams.get(i + 1);
              }
 else               if (param.equals(TextToSpeech.Engine.TTS_KEY_PARAM_COUNTRY)) {
                country=speechItem.mParams.get(i + 1);
              }
 else               if (param.equals(TextToSpeech.Engine.TTS_KEY_PARAM_VARIANT)) {
                variant=speechItem.mParams.get(i + 1);
              }
 else               if (param.equals(TextToSpeech.Engine.TTS_KEY_PARAM_UTTERANCE_ID)) {
                utteranceId=speechItem.mParams.get(i + 1);
              }
            }
          }
          if (language.length() > 0) {
            setLanguage("String_Node_Str",language,country,variant);
          }
        }
        nativeSynth.synthesizeToFile(speechItem.mText,speechItem.mFilename);
      }
 catch (      InterruptedException e) {
        Log.e("String_Node_Str","String_Node_Str");
        e.printStackTrace();
      }
 finally {
        if (utteranceId.length() > 0) {
          dispatchUtteranceCompletedCallback(utteranceId,speechItem.mCallingApp);
        }
        if (synthAvailable) {
          synthesizerLock.unlock();
        }
        processSpeechQueue();
      }
    }
  }
  Thread synth=(new Thread(new SynthThread()));
  synth.setPriority(Thread.MIN_PRIORITY);
  synth.start();
}