Realm switcher broken on variable edit pages

The idea is that forms in 'variable module' pages should handle the realms themselves (before building the forms) so we shouldn't be using 'hacks' like switching the global variables for that.

As a first step, merged variable_realm_admin module into variable_admin so the module is full aware of realms and we can skip realm hooks stepping into 'regular' variable_admin forms.

Finally, added some realm parameters for all these admin pages.

Sorry to re-open but I think I stumbled upon the same problem using version 2.1 of Variable (and latest Commerce Email). Maybe its an issue of Commerce Email but changing a line in variable.module fixed this for me.

Commerce Email uses 'page arguments' => array('variable_group_form', 'commerce_email'), in hook_menu to "create" its settings page. I noticed that the realm switcher is not displayed on this form (admin/commerce/config/email) because the function variable_form_alter() does call the implementations of hook_variable_settings_form_alter() only for forms having "system_settings_form_submit" as submit callback.
variable_group_form() however is using "variable_settings_form_submit".

Changing variable_form_alter() to this helped (simply moved the foreach outside the if-clause):

<?php
function variable_form_alter(&$form, &$form_state, $form_id) {
  if (isset($form['#submit']) && is_array($form['#submit']) && in_array('system_settings_form_submit', $form['#submit'])) {
    // Replace submit callback and use our own function.
    $form['#submit'] = str_replace('system_settings_form_submit', 'variable_settings_form_submit', $form['#submit']);
  }
  foreach (module_implements('variable_settings_form_alter') as $module) {
    $function = $module . '_variable_settings_form_alter';
    $function($form, $form_state, $form_id);
  }
}
?>

(attached patch is based on version 7.x-2.1)