User loses track of the selected categories if the module is configured to not include the category in the subject

Hi !

When the category is not included in the subject, all categories and recipients are combined in a general 'All categories combined' category. Thus you lose track of which categories you sent the message.

The following code combines the categories names. For example, 'Category A', 'Category B', 'Category C' categories, if selected, are combined into 'Category A, Category B, Category C'.

It should replace the block of code at line 562 in mass_contact.page.inc.

    // If the module is configured to not include the category in the subject,
    // combine all users in all categories into a single listing of recpients.
    if (!variable_get('mass_contact_category_override', 1)) {
      $combined_categories = implode(', ', array_keys($recipient_lists));

      $new_recipient_list = array($combined_categories => array());

      // Cycle through all the categories adding all the recipients to the one
      // list.
      foreach ($recipient_lists as $category) {
        if (!empty($new_recipient_list[$combined_categories]['recipients'])) {
          $new_recipient_list[$combined_categories]['recipients'] = array_merge($new_recipient_list[$combined_categories]['recipients'], $category['recipients']);
        }
        else {
          $new_recipient_list[$combined_categories]['recipients'] = $category['recipients'];
        }
      }

      // Add the subject.
      $new_recipient_list[$combined_categories]['subject'] = t('@subject', array('@subject' => $form_state['values']['subject']));

      // Set the original list to the new combined, unduplicated list.
      $new_recipient_list[$combined_categories]['recipients'] = array_unique($new_recipient_list[$combined_categories]['recipients']);
      $recipient_lists = $new_recipient_list;
    }