warning: preg_match() with locale module search box

Are you sure that this module causes the warning? This comes from the code inside drupal_validate_utf8(). Which might be used by some filter on your site, but is not used by l10n_client itself. It might use drupal_validate_utf8() indirectly though. The "search engine" you mention is the search box with the X by its side at the bottom part of the page?

Hm, interesting. It would be great if someone else could reproduce this.

Here is a way to reproduce:

Do a fresh drupal 6.0 install, enable the l10n_client module (and its dependencies). Enable "search box" in garland theme settings, so the search box is omnipresent in the left sidebar and type random search strings.
Result: Every result page will display this error.

I can confirm, that if l10n_client module is not enabled, there is not the message warning: preg_match() expects parameter 2 to be string, array given in /path/to/drupal6/includes/bootstrap.inc on line 721.

Function drupal_validate_utf8() triggers the warning, which expects to preg_match a string, but is given an array. If one explicitly typecasts the passed $text var, the function will work. The array passed to the function which causes the warning comes from the function l10n_client_search(), from l10n_client.module, line 210.

Then I got interested as to why this specific form api array is passed through the drupal_validate_utf8() function. My take is it, that former function actually implements the hook_search() function. I don't know if this is intended here ?

function l10n_client_search() {
  global $language;
  // Selector and editing form.
  $form = array();
  $form['search'] = array(
    '#type' => 'textfield',
  );
  $form['clear-button'] = array(
    '#value' => "<input id='search-filter-clear' class='form-submit' type='button' value='".t('X')."'/>",
  );
  return $form;
}

After I renamed the above function to l10n_client_search_form() the warning message went away.

Yes, it sounds reasonable that it indeed implements the search hook.

I committed this change to fix the issue: http://cvs.drupal.org/viewcvs/drupal/contributions/modules/l10n_client/l... Thanks for the analysis, much appreciated. Now onto releasing the fixes.

You're welcome :)