=== modified file 'modules/user.module'
--- modules/user.module	
+++ modules/user.module	
@@ -477,6 +477,10 @@
 
   if ($type == 'validate' && $category == 'account') {
     return _user_edit_validate(arg(1), $edit);
+  }
+
+  if ($type == 'submit' && $category == 'account') {
+    return _user_edit_submit(arg(1), $edit);
   }
 
   if ($type == 'categories') {
@@ -1171,7 +1175,7 @@
     $form['account']['status'] = array('#type' => 'radios', '#title' => t('Status'), '#default_value' => $edit['status'], '#options' => array(t('Blocked'), t('Active')));
   }
   if (user_access('administer access control')) {
-    $form['account']['roles'] = array('#type' => 'checkboxes', '#title' => t('Roles'), '#default_value' => array_keys($edit['roles']), '#options' => user_roles(1), '#description' => t('Select at least one role.  The user receives the combined permissions of all of the selected roles.'), '#required' => TRUE);
+    $form['account']['roles'] = array('#type' => 'checkboxes', '#title' => t('Roles'), '#default_value' => array_keys((array)$edit['roles']), '#options' => user_roles(1), '#description' => t('Select at least one role.  The user receives the combined permissions of all of the selected roles.'), '#required' => TRUE);
   }
 
   // Picture/avatar:
@@ -1188,6 +1192,7 @@
 }
 
 function _user_edit_validate($uid, &$edit) {
+  $user = user_load(array('uid' => $uid));
   // Validate the username:
   if (user_access('change own username') || user_access('administer users')) {
     if ($error = user_validate_name($edit['name'])) {
@@ -1200,8 +1205,8 @@
       form_set_error('name', t('The name %name has been denied access.', array('%name' => theme('placeholder', $edit['name']))));
     }
   }
-  else {
-    unset($edit['name']);
+  elseif ($edit['name'] != $user->name) {
+    form_set_error('name', t('You do not have access to change this username'));
   }
 
   // Validate the e-mail address:
@@ -1219,18 +1224,15 @@
   if (user_access('administer access control') && $_GET['q'] != 'admin/user/create') {
     if (!$edit['roles']) {
       form_set_error('roles', t('You must select at least one role.'));
-      $edit['roles'] = array();
     }
   }
 
   // If required, validate the uploaded picture.
   if ($file = file_check_upload('picture')) {
-    $user = user_load(array('uid' => $uid));
     user_validate_picture($file, $edit, $user);
   }
   // Delete picture if requested, and if no replacement picture was given.
   else if ($edit['picture_delete']) {
-    $user = user_load(array('uid' => $uid));
     if ($user->picture && file_exists($user->picture)) {
       file_delete($user->picture);
     }
@@ -1241,16 +1243,19 @@
   if ($edit['pass1']) {
     $edit['pass1'] = trim($edit['pass1']);
     $edit['pass2'] = trim($edit['pass2']);
-    if ($edit['pass1'] == $edit['pass2']) {
-      $edit['pass'] = $edit['pass1'];
-    }
-    else {
+    if ($edit['pass1'] != $edit['pass2']) {
       form_set_error('pass2', t('The specified passwords do not match.'));
     }
   }
-  unset($edit['pass1'], $edit['pass2']);
-
-  return $edit;
+}
+
+function _user_edit_submit($uid, &$edit) {
+  $pass = trim($edit['pass1']);
+  if (!empty($pass)) {
+    $edit['pass'] = $pass;
+    unset($edit['pass1'], $edit['pass2']);
+  }
+  $edit['roles'] = array_filter($edit['roles']);
 }
 
 function user_edit($category = 'account') {
@@ -1304,7 +1309,10 @@
 
 function user_edit_submit($form_id, $form_values) {
   $account = $form_values['_account'];
-  user_save($account, $form_values, $form_values['_category']);
+  $category = $form_values['_category'];
+  unset($form_values['_account'], $form_values['submit'], $form_values['delete'], $form_values['form_id'], $form_values['_category']);
+  user_module_invoke('submit', $form_values, $form_values, $category);
+  user_save($account, $form_values, $category);
   // Delete that user's menu cache.
   cache_clear_all('menu:'. $account->uid, TRUE);
   drupal_set_message(t('The changes have been saved.'));