Right URL rewrite after 404 redirect

Question

Is it possible to rewrite the url in a 404 redirect according to the page which is actually being displayed ?

For example, if the non-existent url "/fzenk" is requested, and you have configured the default 404 error page to be the front-page, the url in the address bar after the redirect should be front-page's.

I tried Global Redirect module but it didn't work. Is it possible to do the 404 redirect = URL-rewrite with another module or should we request a new feature ?

---

Update:

While it is possible to do it, it seems to be a bad idea to rewrite 404 pages url.

Answer 1

Thanks to Krister Andersson answer, I seem to have got it right.

function THEME_preprocess_page(&$variables, $hook) {
   $status = drupal_get_http_header("status");  
   if($status == "404 Not Found") {
      // get the configured 404 error page url :
      $not_found_url = variable_get('site_404');
      unset($_GET['destination']);
      drupal_goto($not_found_url);
   }
}

It will rewrite the url according to the configured default 404 error page, it works with multilingual variable too.

Answer 2

If you would like to redirect all your 404 requests to the frontpage I think you could use the template_preprocess_page() hook and drupal_get_http_status() to check for a 404:

function THEME_preprocess_page(&$variables, $hook) { 
   $status = drupal_get_http_header("status");  
   if ($status == "404 Not Found") {      
      header("Location: http://exampel.com/");
      drupal_exit();
   }
}  

Answer 3

I couldn't seem to get the 403 redirect working with the methods suggested in this thread, so I used a custom menu entry instead, added the path to the native drupal error redirect page, and Bob's your uncle. =o)

/**
 * Implements hook_menu().
 * 
 */
function MYMODULE_menu() {

  $items = array();

  // On the admin/config/system/site-information form, set the 404 and 403 
  // redirects to MYMODULE-custom-error/40x
  $items['MYMODULE-custom-error'] = array(
    'page callback' => 'MYMODULE_custom_error',
    'page arguments' => array(1),
    'access arguments' => array('access content'),
  );

  return $items;
}

/**
 * Utility function to redirect users to the home page on 404 and 403 errors; 
 * note the settings on admin/config/system/site-information
 */
function MYMODULE_custom_error($error) {
  unset($_GET['destination']);
  drupal_goto();
}

Answer 4

For Drupal 6, here is a slightly modified code:

function THEME_preprocess_page(&$variables) { 
  $status = drupal_get_headers();
  if(preg_match('/404 Not Found/', $status)) {      
    unset($_GET['destination']);
header("Location: /pagenotfound");
    exit;
  }
}

Here we couldn't use drupal_goto() for redirection. Because this results in infinite loop.