Program: 8343
Project: 8343
Buggy source:
/** 
 * Creates dialog
 */
@Override public Dialog onCreateDialog(Bundle savedInstanceState){
  final FragmentActivity activity=getActivity();
  final Uri deleteUri=getArguments().getParcelable(ARG_DELETE_URI);
  final String deleteFilename=FileHelper.getFilename(getActivity(),deleteUri);
  CustomAlertDialogBuilder alert=new CustomAlertDialogBuilder(activity);
  alert.setMessage(this.getString(R.string.file_delete_confirmation,deleteFilename));
  alert.setPositiveButton(R.string.btn_delete,new DialogInterface.OnClickListener(){
    @Override public void onClick(    DialogInterface dialog,    int id){
      dismiss();
      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
        try {
          if (DocumentsContract.deleteDocument(getActivity().getContentResolver(),deleteUri)) {
            Toast.makeText(getActivity(),getActivity().getString(R.string.file_delete_successful,deleteFilename),Toast.LENGTH_LONG).show();
            return;
          }
        }
 catch (        UnsupportedOperationException e) {
          Log.d(Constants.TAG,"String_Node_Str",e);
        }
      }
      try {
        if (getActivity().getContentResolver().delete(deleteUri,null,null) > 0) {
          Toast.makeText(getActivity(),getActivity().getString(R.string.file_delete_successful,deleteFilename),Toast.LENGTH_LONG).show();
          return;
        }
      }
 catch (      UnsupportedOperationException e) {
        Log.d(Constants.TAG,"String_Node_Str",e);
      }
      if (new File(deleteUri.getPath()).delete()) {
        Toast.makeText(getActivity(),getActivity().getString(R.string.file_delete_successful,deleteFilename),Toast.LENGTH_LONG).show();
        return;
      }
      Toast.makeText(getActivity(),getActivity().getString(R.string.error_file_delete_failed,deleteFilename),Toast.LENGTH_LONG).show();
    }
  }
);
  alert.setNegativeButton(android.R.string.cancel,new DialogInterface.OnClickListener(){
    public void onClick(    DialogInterface dialog,    int id){
      dismiss();
    }
  }
);
  alert.setCancelable(true);
  return alert.show();
}

Fixed version (ground truth):
/** 
 * Creates dialog
 */
@Override public Dialog onCreateDialog(Bundle savedInstanceState){
  final FragmentActivity activity=getActivity();
  final Uri[] deleteUris=(Uri[])getArguments().getParcelableArray(ARG_DELETE_URIS);
  final StringBuilder deleteFileNames=new StringBuilder();
  final HashMap<Uri,String> deleteFileNameMap=new HashMap<>();
  for (  Uri deleteUri : deleteUris) {
    String deleteFileName=FileHelper.getFilename(getActivity(),deleteUri);
    deleteFileNames.append('\n').append(deleteFileName);
    deleteFileNameMap.put(deleteUri,deleteFileName);
  }
  CustomAlertDialogBuilder alert=new CustomAlertDialogBuilder(activity);
  alert.setMessage(this.getString(R.string.file_delete_confirmation,deleteFileNames.toString()));
  alert.setPositiveButton(R.string.btn_delete,new DialogInterface.OnClickListener(){
    @Override public void onClick(    DialogInterface dialog,    int id){
      dismiss();
      ArrayList<String> failedFileNameList=new ArrayList<>();
      for (      Uri deleteUri : deleteUris) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
          try {
            if (DocumentsContract.deleteDocument(getActivity().getContentResolver(),deleteUri)) {
              continue;
            }
          }
 catch (          Exception e) {
            Log.d(Constants.TAG,"String_Node_Str",e);
          }
        }
        try {
          if (getActivity().getContentResolver().delete(deleteUri,null,null) > 0) {
            continue;
          }
        }
 catch (        Exception e) {
          Log.d(Constants.TAG,"String_Node_Str",e);
        }
        if (new File(deleteUri.getPath()).delete()) {
          continue;
        }
        failedFileNameList.add(deleteFileNameMap.get(deleteUri));
      }
      StringBuilder failedFileNames=new StringBuilder();
      if (!failedFileNameList.isEmpty()) {
        for (        String failedFileName : failedFileNameList) {
          failedFileNames.append('\n').append(failedFileName);
        }
        failedFileNames.append('\n').append(getActivity().getString(R.string.error_file_delete_failed));
      }
      Toast.makeText(getActivity(),getActivity().getString(R.string.file_delete_successful,deleteUris.length - failedFileNameList.size(),deleteUris.length,failedFileNames.toString()),Toast.LENGTH_LONG).show();
      if (onDeletedListener != null) {
        onDeletedListener.onDeleted();
      }
    }
  }
);
  alert.setNegativeButton(android.R.string.cancel,new DialogInterface.OnClickListener(){
    public void onClick(    DialogInterface dialog,    int id){
      dismiss();
    }
  }
);
  alert.setCancelable(true);
  return alert.show();
}