diff -u b/core/modules/comment/comment.module b/core/modules/comment/comment.module
--- b/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -1536,8 +1536,7 @@
     if (!isset($authenticated_post_comments)) {
       // We only output a link if we are certain that users will get permission
       // to post comments by logging in.
-      $comment_roles = user_roles(TRUE, 'post comments');
-      $authenticated_post_comments = isset($comment_roles[DRUPAL_AUTHENTICATED_RID]);
+      $authenticated_post_comments = user_role_has_permission(DRUPAL_AUTHENTICATED_RID, 'post comments');
     }
 
     if ($authenticated_post_comments) {
@@ -1606,7 +1605,8 @@
     if (!isset($authenticated_post_comments)) {
       // We only output a link if we are certain that users will get permission
       // to post comments by logging in.
-      $authenticated_post_comments = user_role_has_permission(DRUPAL_AUTHENTICATED_RID, 'post comments');
+      $comment_roles = user_roles(TRUE, 'post comments');
+      $authenticated_post_comments = isset($comment_roles[DRUPAL_AUTHENTICATED_RID]);
     }
 
     if ($authenticated_post_comments) {
diff -u b/core/modules/forum/forum.module b/core/modules/forum/forum.module
--- b/core/modules/forum/forum.module
+++ b/core/modules/forum/forum.module
@@ -177,7 +177,7 @@
       // Anonymous user does not have access to create new topics.
       else {
         // If authenticated users can post new topic, provide a login link.
-        if (user_role_has_permission(DRUPAL_AUTHENTICATED_RID, 'create forum content')) {
+        if (user_role_load(DRUPAL_AUTHENTICATED_RID)->hasPermission('create forum content')) {
           $links['login'] = array(
             '#theme' => 'menu_local_action',
             '#link' => array(
reverted:
--- b/core/modules/user/user.module
+++ a/core/modules/user/user.module
@@ -2026,20 +2026,3 @@
   // Destroy the current session, and reset $user to the anonymous user.
   session_destroy();
 }
-
-/**
- * Determines whether a role has given permission.
- * @param string $rid
- *   role IDs of interest
- * @param string $permission
- *   A string containing a permission.
- *
- * @return boolean
- *   TRUE if the given role has the requested permission.
- */
-function user_role_has_permission($rid, $permission) {
-  // Get permissions of role given by ID.
-  $perms = user_role_permissions(array($rid => $rid));
-  // Returns TRUE if the role has the requested permission.
-  return in_array($permission, $perms[$rid]);
-}