file_entity_hacks.info

name = File entity hacks
description = Temporary hacks to File entity module.
core = 7.x
php = 5.2.4

file_entity_hacks.module

<?php

function file_entity_hacks_menu_alter(&$items) {

  // Override file upload form page callback to inject new allowed file extensions.
  if (module_exists('file_entity')) {
    $items['file/add']['page arguments'] = array('file_entity_hacks_file_entity_add_upload');
    $items['file/add']['file'] = 'file_entity_hacks.pages.inc';
    $items['file/add']['file path'] = drupal_get_path('module', 'file_entity_hacks');
    if (module_exists('plupload') && module_exists('multiform')) {
      $items['file/add']['page arguments'] = array('file_entity_hacks_file_entity_add_upload_multiple');
    }
  }
}

file_entity_hacks.pages.inc

<?php


/**
 * Upload file form with new file extensions.
 */
function file_entity_hacks_file_entity_add_upload($form, &$form_state, $params = array()) {
  module_load_include('inc', 'file_entity', 'file_entity.pages');
  $params['file_extensions'] = variable_get('media__file_extensions', 'jpg jpeg gif png txt doc xls pdf ppt pps odt ods odp');
  $form = file_entity_add_upload($form, $form_state, $params);
  $form['#submit'] = array('file_entity_add_upload_submit');
  return $form;
}

/**
 * Mulstiple upload file form with new file extensions.
 */
function file_entity_hacks_file_entity_add_upload_multiple($form, &$form_state, $params = array()) {
  module_load_include('inc', 'file_entity', 'file_entity.pages');
  $params['file_extensions'] = variable_get('media__file_extensions', 'jpg jpeg gif png txt doc xls pdf ppt pps odt ods odp');
  $form = file_entity_add_upload_multiple($form, $form_state, $params);
  $form['#submit'] = array('file_entity_add_upload_multiple_submit');
  return $form;
}