When altering the submit button, the form does not work

Question

We need a <button> instead of an input in our search-form. So I changed the markup accordingly using theme_form_alter:

function giga_form_alter(&$form, &$form_state, $form_id) {
  if ($form_id == 'search_block_form') {
    $form['search_block_form']['#title'] = t('Search'); // Change the text on the label element
    $form['search_block_form']['#title_display'] = 'invisible'; // Toggle label visibilty
    $form['search_block_form']['#size'] = 40;  // define size of the textfield
    $form['search_block_form']['#default_value'] = t('Search'); // Set a default value for the textfield
    $form['actions']['submit'] = array(
      '#type'   => 'markup',
      '#prefix' => '<button type="submit" class="btn btn-primary">',
      '#suffix' => '</button>',
      '#markup' => '<i class="icon-search icon-white"></i>'
    );
    $form['actions']['submit']['#executes_submit_callback'] = true;
    $form['actions']['#type'] = 'none';
    $form['#attributes']['class'][] = 'search-quick';

    // Alternative (HTML5) placeholder attribute instead of using the javascript
    $form['search_block_form']['#attributes']['placeholder'] = t('Search');
  }
}

However, I can submit the form, but the search won't be processed. The page reloads and I'm not redirect to the search results. However when I remove $form['actions']['submit'] = array([…]); it all works fine.

I'm not quite sure what's going on here.

Answer 1

Try to use this:

Drupal 6:

 $form['actions']['submit']['#type'] = "Submit";

Drupal 7:

$form['actions']['submit'] = array(
  '#type'  => 'submit',
);

Answer 2

I just had the same problem. All the needed was adding this.

$form['actions']['submit'] = array(
  '#type'  => 'submit',
);