Index: openid.module
===================================================================
--- openid.module	(revision 344)
+++ openid.module	(working copy)
@@ -6,6 +6,8 @@
  * Impelement OpenID Relying Party support for Drupal
  */
 
+define('OPENID_DUMMY_EMAIL', 'postmaster@localhost');
+
 /**
  * Implementation of hook_menu.
  */
@@ -19,6 +21,13 @@
       'access' => TRUE,
       'type' => MENU_CALLBACK,
       );
+    $items[] = array(
+      'path' => 'admin/settings/openid',
+      'title' => t('OpenID settings'),
+      'callback'=> 'drupal_get_form',
+      'access' => user_access('administer users'),
+      'callback arguments' => array('openid_settings'),
+    );
   }
   else {
     if (arg(0) == 'user' && is_numeric(arg(1))) {
@@ -481,7 +490,17 @@
     // Register new user
     $form = drupal_retrieve_form('user_register');
     $edit['name'] = (empty($response['openid.sreg.nickname'])) ? $identity : $response['openid.sreg.nickname'];
-    $edit['mail'] = (empty($response['openid.sreg.email'])) ? '' : $response['openid.sreg.email'];
+    if (empty($response['openid.sreg.email'])) {
+      if (variable_get('openid_allow_empty_email', false)) {
+        $edit['mail'] = variable_get('openid_dummy_email', OPENID_DUMMY_EMAIL);
+      }
+      else {
+        $edit['mail'] = '';
+      }
+    }
+    else {
+      $edit['mail'] = $response['openid.sreg.email'];
+    }
     $edit['pass']  = user_password();
     $edit['status'] = variable_get('user_register', 1) == 1;
     $edit['response'] = $response;
@@ -598,3 +617,31 @@
 
   return $valid;
 }
+
+function openid_settings() {
+  $form['openid_allow_empty_email'] = array(
+    '#type' => 'checkbox',
+    '#title' => t('Allow empty emails in successful OpenID authentication'),
+    '#default_value' => variable_get('openid_allow_empty_email', false),
+  );
+  $form['openid_dummy_email'] = array(
+    '#type' => 'textfield',
+    '#title' => t('"Dummy" address for empty email fields'),
+    '#default_value' => variable_get('openid_dummy_email', OPENID_DUMMY_EMAIL),
+    '#size' => 30,
+    '#maxlength' => 128,
+    '#required' => false,
+    '#description' => t('A "dummy" email address to use if "Allow empty emails" is checked.  The user may change this later.'),
+  );
+  return system_settings_form($form);
+}
+
+function openid_settings_validate($form_id, $form_values) {
+  if (!valid_email_address($form_values['openid_dummy_email'])) {
+    form_set_error('openid_dummy_email', t('Invalid email address.'));
+  }
+}
+
+function openid_settings_submit($form_id, $form_values) {
+  system_settings_form_submit($form_id, $form_values);
+}