Program: 162545
Project: 162545
Buggy source:
public void mkFile(final HFile path,final Main ma){
  final Toast toast=Toast.makeText(ma.getActivity(),ma.getString(R.string.creatingfile),Toast.LENGTH_SHORT);
  toast.show();
  Operations.mkfile(path,ma.getActivity(),BaseActivity.rootMode,new Operations.ErrorCallBack(){
    @Override public void exists(    final HFile file){
      ma.getActivity().runOnUiThread(new Runnable(){
        @Override public void run(){
          if (toast != null)           toast.cancel();
          Toast.makeText(mainActivity,mainActivity.getString(R.string.fileexist),Toast.LENGTH_SHORT).show();
          if (ma != null && ma.getActivity() != null) {
            mkfile(file.getMode(),file.getParent(),ma);
          }
        }
      }
);
    }
    @Override public void launchSAF(    HFile file){
      ma.getActivity().runOnUiThread(new Runnable(){
        @Override public void run(){
          if (toast != null)           toast.cancel();
          mainActivity.oppathe=path.getPath();
          mainActivity.operation=DataUtils.NEW_FOLDER;
          guideDialogForLEXA(mainActivity.oppathe);
        }
      }
);
    }
    @Override public void launchSAF(    HFile file,    HFile file1){
    }
    @Override public void done(    HFile hFile,    final boolean b){
      ma.getActivity().runOnUiThread(new Runnable(){
        @Override public void run(){
          if (b) {
            ma.updateList();
          }
 else           Toast.makeText(ma.getActivity(),ma.getString(R.string.operationunsuccesful),Toast.LENGTH_SHORT).show();
        }
      }
);
    }
    @Override public void invalidName(    final HFile file){
      ma.getActivity().runOnUiThread(new Runnable(){
        @Override public void run(){
          if (toast != null)           toast.cancel();
          Toast.makeText(ma.getActivity(),ma.getString(R.string.invalid_name) + "String_Node_Str" + file.getName(),Toast.LENGTH_LONG).show();
        }
      }
);
    }
  }
);
}

Fixed version (ground truth):
public void mkFile(final HFile path,final Main ma){
  final Toast toast=Toast.makeText(ma.getActivity(),ma.getString(R.string.creatingfile),Toast.LENGTH_SHORT);
  toast.show();
  Operations.mkfile(path,ma.getActivity(),BaseActivity.rootMode,new Operations.ErrorCallBack(){
    @Override public void exists(    final HFile file){
      ma.getActivity().runOnUiThread(new Runnable(){
        @Override public void run(){
          if (toast != null)           toast.cancel();
          Toast.makeText(mainActivity,mainActivity.getString(R.string.fileexist),Toast.LENGTH_SHORT).show();
          if (ma != null && ma.getActivity() != null) {
            mkfile(file.getMode(),file.getParent(),ma);
          }
        }
      }
);
    }
    @Override public void launchSAF(    HFile file){
      ma.getActivity().runOnUiThread(new Runnable(){
        @Override public void run(){
          if (toast != null)           toast.cancel();
          mainActivity.oppathe=path.getPath();
          mainActivity.operation=DataUtils.NEW_FILE;
          guideDialogForLEXA(mainActivity.oppathe);
        }
      }
);
    }
    @Override public void launchSAF(    HFile file,    HFile file1){
    }
    @Override public void done(    HFile hFile,    final boolean b){
      ma.getActivity().runOnUiThread(new Runnable(){
        @Override public void run(){
          if (b) {
            ma.updateList();
          }
 else           Toast.makeText(ma.getActivity(),ma.getString(R.string.operationunsuccesful),Toast.LENGTH_SHORT).show();
        }
      }
);
    }
    @Override public void invalidName(    final HFile file){
      ma.getActivity().runOnUiThread(new Runnable(){
        @Override public void run(){
          if (toast != null)           toast.cancel();
          Toast.makeText(ma.getActivity(),ma.getString(R.string.invalid_name) + "String_Node_Str" + file.getName(),Toast.LENGTH_LONG).show();
        }
      }
);
    }
  }
);
}