Test that dispayNamesInGroup(s) always returns uid as key in the result array

tests/lib/group.php

@@ -109,6 +109,24 @@ class Test_Group extends PHPUnit_Framework_TestCase {
 		$this->assertEquals(array(), OC_Group::getGroups());
 	}
 
+	public function testDisplayNamesInGroup() {
+		OC_Group::useBackend(new OC_Group_Dummy());
+		$userBackend = new \OC_User_Dummy();
+		\OC_User::getManager()->registerBackend($userBackend);
+
+		$group1 = uniqid();
+		$user1 = 'uid1';
+		$user2 = 'uid2';
+		OC_Group::createGroup($group1);
+		$userBackend->createUser($user1, '');
+		$userBackend->createUser($user2, '');
+		OC_Group::addToGroup($user1, $group1);
+		OC_Group::addToGroup($user2, $group1);
+		//Dummy backend does not support setting displaynames, uid will always
+		//be returned. This checks primarily, that the return format is okay.
+		$expected = array($user1 => $user1, $user2 => $user2);
+		$this->assertEquals($expected, OC_Group::displayNamesInGroup($group1));
+	}
 
 	public function testUsersInGroup() {
 		OC_Group::useBackend(new OC_Group_Dummy());