Issue #2394517 by opdavies: Add a function to check if a user has a certain role

CHANGELOG.txt

@@ -1,6 +1,8 @@
 
 Drupal 7.36, xxxx-xx-xx (development version)
 -----------------------
+- Added a user_has_role() function to check whether a user has a particular
+  role (API addition).
 - Fixed installation failures when an opcode cache is enabled.
 - Fixed a bug in the Drupal 6 to Drupal 7 upgrade path which caused private
   files to be inaccessible.

modules/user/user.module

@@ -848,6 +848,26 @@ function user_is_blocked($name) {
     ->execute()->fetchObject();
 }
 
+/**
+ * Checks if a user has a role.
+ *
+ * @param int $rid
+ *   A role ID.
+ *
+ * @param object|null $account
+ *   (optional) A user account. Defaults to the current user.
+ *
+ * @return bool
+ *   TRUE if the user has the role, or FALSE if not.
+ */
+function user_has_role($rid, $account = NULL) {
+  if (!$account) {
+    $account = $GLOBALS['user'];
+  }
+
+  return isset($account->roles[$rid]);
+}
+
 /**
  * Implements hook_permission().
  */