Add get_editable_roles() and role filtering. Props jeremyclarke. fixes #8770

git-svn-id: http://svn.automattic.com/wordpress/trunk@10323 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/template.php

@@ -2621,11 +2621,10 @@ function wp_dropdown_roles( $selected = false ) {
 	$p = '';
 	$r = '';
 	
-	$role_names = $wp_roles->role_names;
-	$role_names = apply_filters('role_names_listing', $role_names);
+	$editable_roles = get_editable_roles();
 	
-	foreach( $role_names as $role => $name ) {
-		$name = translate_with_context($name);
+	foreach( $editable_roles as $role => $details ) {
+		$name = translate_with_context($details['name']);
 		if ( $selected == $role ) // Make default first in list
 			$p = "\n\t<option selected='selected' value='$role'>$name</option>";
 		else

wp-admin/includes/user.php

@@ -9,9 +9,12 @@
 /**
  * Creates a new user from the "Users" form using $_POST information.
  *
- * {@internal Missing Long Description}}
+ * It seems that the first half is for backwards compatibility, but only
+ * has the ability to alter the user's role. Wordpress core seems to 
+ * use this function only in the second way, running edit_user() with
+ * no id so as to create a new user.
  *
- * @since unknown
+ * @since 2.0
  *
  * @param int $user_id Optional. User ID.
  * @return null|WP_Error|int Null when adding user, WP_Error or User ID integer when no parameters.
@@ -22,7 +25,13 @@ function add_user() {
 		$user_id = (int) func_get_arg( 0 );
 
 		if ( isset( $_POST['role'] ) ) {
+			// Don't let anyone with 'edit_users' (admins) edit their own role to something without it.
 			if( $user_id != $current_user->id || $wp_roles->role_objects[$_POST['role']]->has_cap( 'edit_users' ) ) {
+				// If the new role isn't editable by the logged-in user die with error
+				$editable_roles = get_editable_roles();
+				if (!$editable_roles[$_POST['role']])
+					wp_die(__('You can’t give users that role.'));
+				
 				$user = new WP_User( $user_id );
 				$user->set_role( $_POST['role'] );
 			}
@@ -34,14 +43,14 @@ function add_user() {
 }
 
 /**
- * {@internal Missing Short Description}}
+ * Edit user settings based on contents of $_POST
  *
- * {@internal Missing Long Description}}
+ * Used on user-edit.php and profile.php to manage and process user options, passwords etc.
  *
- * @since unknown
+ * @since 2.0
  *
  * @param int $user_id Optional. User ID.
- * @return unknown
+ * @return int user id of the updated user
  */
 function edit_user( $user_id = 0 ) {
 	global $current_user, $wp_roles, $wpdb;
@@ -65,8 +74,15 @@ function edit_user( $user_id = 0 ) {
 		$pass2 = $_POST['pass2'];
 
 	if ( isset( $_POST['role'] ) && current_user_can( 'edit_users' ) ) {
+
+		// Don't let anyone with 'edit_users' (admins) edit their own role to something without it.
 		if( $user_id != $current_user->id || $wp_roles->role_objects[$_POST['role']]->has_cap( 'edit_users' ))
-			$user->role = $_POST['role'];
+			$user->role = $_POST['role']; 
+
+		// If the new role isn't editable by the logged-in user die with error
+		$editable_roles = get_editable_roles();
+		if (!$editable_roles[$_POST['role']])
+			wp_die(__('You can’t give users that role.'));
 	}
 
 	if ( isset( $_POST['email'] ))
@@ -241,6 +257,31 @@ function get_editable_user_ids( $user_id, $exclude_zeros = true, $post_type = 'p
 	return $wpdb->get_col( $query );
 }
 
+/**
+ * Fetch a filtered list of user roles that the current user is 
+ * allowed to edit. 
+ *
+ * Simple function who's main purpose is to allow filtering of the 
+ * list of roles in the $wp_roles object so that plugins can remove
+ * innappropriate ones depending on the situation or user making edits.
+ * Specifically because without filtering anyone with the edit_users
+ * capability can edit others to be administrators, even if they are
+ * only editors or authors. This filter allows admins to delegate
+ * user management. 
+ *
+ * @since 2.8
+ *
+ * @return unknown
+ */
+function get_editable_roles() {
+	global $wp_roles;
+
+	$all_roles = $wp_roles->roles;
+	$editable_roles = apply_filters('editable_roles', $all_roles);	
+	
+	return $editable_roles;
+}
+
 /**
  * {@internal Missing Short Description}}
  *

wp-admin/users.php

@@ -39,6 +39,7 @@ if ( empty($_REQUEST) ) {
 
 switch ($doaction) {
 
+/* Bulk Dropdown menu Role changes */
 case 'promote':
 	check_admin_referer('bulk-users');
 
@@ -47,8 +48,9 @@ case 'promote':
 		exit();
 	}
 
-	if ( !current_user_can('edit_users') )
-		wp_die(__('You can’t edit users.'));
+	$editable_roles = get_editable_roles();
+	if (!$editable_roles[$_REQUEST['new_role']])
+		wp_die(__('You can’t give users that role.'));
 
 	$userids = $_REQUEST['users'];
 	$update = 'promote';