From 555970c95096e24fa1c555729763d75e1920dc81 Mon Sep 17 00:00:00 2001
From: Andrew Nacin <nacin@git.wordpress.org>
Date: Wed, 7 Mar 2012 03:41:56 +0000
Subject: [PATCH] Internally cache return values of wp_salt(). Always run the
 filter. Big performance gains on a pageload that generates hundreds of
 nonces. see #19599.

git-svn-id: https://develop.svn.wordpress.org/trunk@20135 602fd350-edb4-49c9-b593-d223f7449a82
---
 wp-includes/pluggable.php | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/wp-includes/pluggable.php b/wp-includes/pluggable.php
index 08623f5e82..b9764f173a 100644
--- a/wp-includes/pluggable.php
+++ b/wp-includes/pluggable.php
@@ -1310,6 +1310,10 @@ if ( !function_exists('wp_salt') ) :
 function wp_salt( $scheme = 'auth' ) {
 	global $wp_secret_key_default; // This is set for localized builds for versions > 3.4.0.
 
+	static $cached_salts = array();
+	if ( isset( $cached_salts[ $scheme ] ) )
+		return apply_filters( 'salt', $cached_salts[ $scheme ], $scheme );
+
 	static $duplicated_keys;
 	if ( null === $duplicated_keys ) {
 		$duplicated_keys = array( 'put your unique phrase here' => true );
@@ -1355,7 +1359,8 @@ function wp_salt( $scheme = 'auth' ) {
 		$salt = hash_hmac( 'md5', $scheme, $key );
 	}
 
-	return apply_filters('salt', $key . $salt, $scheme);
+	$cached_salts[ $scheme ] = $key . $salt;
+	return apply_filters( 'salt', $cached_salts[ $scheme ], $scheme );
 }
 endif;