Index: tests/user.php
===================================================================
--- tests/user.php	(revision 954)
+++ tests/user.php	(working copy)
@@ -266,6 +266,16 @@
 		$this->assertEquals( $user->user_login, $user5->user_login );
 	}
 
+	/**
+	 * @ticket 21495
+	 */
+	 
+	function test_wp_create_user_empty_password(){
+		$user_id = wp_create_user( 'foobar', '', 'email@example48.com' );
+		$this->assertInstanceOf( 'WP_Error', $user_id );
+
+	}
+
 	function test_get() {
 		$user_id = $this->factory->user->create( array(
 			'role' => 'author',