Combine taxonomy menu + main menu

combine-tax-main-menu.php

 /**
 * Implements template_preprocess_taxonomy_menu_block()
 * Adds the main-menu items to this taxonomy menu block
 */
function the_aim_theme_commerce_preprocess_taxonomy_menu_block(&$variables){
  //only for block with delta == 1
  if ( 1 == $variables['config']['delta']) {
    if(isset($variables['items'][-1])) {
      $links = menu_tree('main-menu');
      foreach ($links as $link) {
        if(isset($link['#original_link']) && !empty($link['#original_link'])) {
          $original_link = $link['#original_link'];
          $variables['items'][$original_link['mlid']] = array('name'=>$original_link['link_title'], 'path'=> drupal_get_path_alias($original_link['link_path']), 'depth'=>0, 'parents'=>array(), 'active_trail'=>'0', 'children'=>array());
        }
      }
    }
  }
}