X-Git-Url: https://scripts.mit.edu/gitweb/autoinstalls/wordpress.git/blobdiff_plain/e08b42e8ad054ec67522d7ac1aaae5dc68cb3d01..e0feb3b2e5b436a06bbb04fbc838d1cd6ec95399:/wp-includes/vars.php

diff --git a/wp-includes/vars.php b/wp-includes/vars.php
index f1e67b62..828fbbb4 100644
--- a/wp-includes/vars.php
+++ b/wp-includes/vars.php
@@ -6,8 +6,11 @@
  * for the browser to set which one is currently being used.
  *
  * Detects which user environment WordPress is being used on.
- * Only attempts to check for Apache and IIS. Two web servers
- * with known permalink capability.
+ * Only attempts to check for Apache, Nginx and IIS -- three web
+ * servers with known pretty permalink capability.
+ *
+ * Note: Though Nginx is detected, WordPress does not currently
+ * generate rewrite rules for it. See https://codex.wordpress.org/Nginx
  *
  * @package WordPress
  */
@@ -115,13 +118,16 @@ $is_iis7 = $is_IIS && intval( substr( $_SERVER['SERVER_SOFTWARE'], strpos( $_SER
 /**
  * Test if the current browser runs on a mobile device (smart phone, tablet, etc.)
  *
- * @return bool true|false
+ * @staticvar bool $is_mobile
+ *
+ * @return bool
  */
 function wp_is_mobile() {
-	static $is_mobile;
+	static $is_mobile = null;
 
-	if ( isset($is_mobile) )
+	if ( isset( $is_mobile ) ) {
 		return $is_mobile;
+	}
 
 	if ( empty($_SERVER['HTTP_USER_AGENT']) ) {
 		$is_mobile = false;