State/province autocomplete not working

I have the same issue (Drupal 6.19 + Location 6.x-3.x-dev (2010-Sep-30)).

I've used firefox to peek arround form elements data, and I've found that #autocomplete_path value of state/province is badly build by default. In my case (default country forced to Spain, 'es' code), the value was
'/?q=location/autocomplete/e', instead of '/?q=location/autocomplete/es' (note that contry code is truncated, and this is the bug).

The cause is a incorrect declaration of the default country code in function location_locationapi(&$obj, $op, $a3 = NULL, $a4 = NULL, $a5 = NULL) in location.module:

function location_locationapi(&$obj, $op, $a3 = NULL, $a4 = NULL, $a5 = NULL) {
  switch ($op) {
    /* ... Other API operations... */

    case 'field_expand':
      switch ($a3) {
    /* ... Other fields expansions ... */
        case 'province':
          drupal_add_js(drupal_get_path('module', 'location') .'/location_autocomplete.js');
          // Original buggy line: $country = $a5['country']['default'] ? $a5['country']['default'] : variable_get('location_default_country', 'us');
          $country = $a5['country'] ? $a5['country'] : variable_get('location_default_country', 'us');
          return array(
            '#type' => 'textfield',
            '#title' => t('State/Province'),
            '#autocomplete_path' => 'location/autocomplete/'. $country,
            '#default_value' => variable_get('location_use_province_abbreviation', 1) ? $obj : location_province_name($country, $obj),
            '#size' => 64,
            '#maxlength' => 64,
            '#description' => NULL,
            // Used by province autocompletion js.
            '#attributes' => array('class' => 'location_auto_province'),
            '#required' => ($a4 == 2),
          );
    /* ... Other fields expansions ... */

Sorry about not providing a .diff file patch... I'm a Drupal newbie and I don't now how to do it... yet... (how embarrassing!!).

Thanks, Realeiko! Fixing the location_locationapi in location.module solved my problem!

I have committed a fix that fixes this issue as well as these two related issues:
#846604: warning: trim() expects parameter 1 to be string, array given in sites/all/modules/location/location.inc on line 498.
#990804: When "Display full province name" is selected, parts of the administrative UI become disabled

The fix was taken from bdragon's DRUPAL-7--4 branch, where he had already fixed this.
The fix checks both $a5['country']['default'] and $a5['country'] as there are times when each is valid.

http://drupal.org/cvs?commit=486596
http://drupal.org/cvs?commit=486594
http://drupal.org/cvs?commit=486600