From a693987b919577c8c4ea7c7ac5a58d730314ae86 Mon Sep 17 00:00:00 2001
From: Peter Wilson <wilson@peterwilson.cc>
Date: Tue, 19 Jul 2016 02:35:31 +0000
Subject: [PATCH] Script Loader: Limit resource hinting to enqueued assets.

Externally hosted script and style dependencies trigger `dns-prefetch` hinting only when enqueued. This removed a bug in which hinting was added on registration.

Renames the function `wp_resource_hints_scripts_styles` to `wp_dependencies_unique_hosts` as the function provides the hosts, not the hinting.

Props swissspidy.
Fixes #37385.

Built from https://develop.svn.wordpress.org/trunk@38100


git-svn-id: http://core.svn.wordpress.org/trunk@38041 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/general-template.php | 32 ++++++++++++++------------------
 wp-includes/version.php          |  2 +-
 2 files changed, 15 insertions(+), 19 deletions(-)

diff --git a/wp-includes/general-template.php b/wp-includes/general-template.php
index 2bcdb43801..ca48499ed3 100644
--- a/wp-includes/general-template.php
+++ b/wp-includes/general-template.php
@@ -2799,7 +2799,7 @@ function wp_site_icon() {
  */
 function wp_resource_hints() {
 	$hints = array(
-		'dns-prefetch' => wp_resource_hints_scripts_styles(),
+		'dns-prefetch' => wp_dependencies_unique_hosts(),
 		'preconnect'   => array( 's.w.org' ),
 		'prefetch'     => array(),
 		'prerender'    => array(),
@@ -2851,31 +2851,27 @@ function wp_resource_hints() {
 }
 
 /**
- * Adds dns-prefetch for all scripts and styles enqueued from external hosts.
+ * Returns a list of unique hosts of all enqueued scripts and styles.
  *
  * @since 4.6.0
+ *
+ * @return array A list of unique hosts of enqueued scripts and styles.
  */
-function wp_resource_hints_scripts_styles() {
+function wp_dependencies_unique_hosts() {
 	global $wp_scripts, $wp_styles;
 
 	$unique_hosts = array();
 
-	if ( is_object( $wp_scripts ) && ! empty( $wp_scripts->registered ) ) {
-		foreach ( $wp_scripts->registered as $registered_script ) {
-			$parsed = wp_parse_url( $registered_script->src );
+	foreach ( array( $wp_scripts, $wp_styles ) as $dependencies ) {
+		if ( $dependencies instanceof WP_Dependencies && ! empty( $dependencies->queue ) ) {
+			foreach ( $dependencies->queue as $handle ) {
+				/* @var _WP_Dependency $dependency */
+				$dependency = $dependencies->registered[ $handle ];
+				$parsed     = wp_parse_url( $dependency->src );
 
-			if ( ! empty( $parsed['host'] ) && ! in_array( $parsed['host'], $unique_hosts ) && $parsed['host'] !== $_SERVER['SERVER_NAME'] ) {
-				$unique_hosts[] = $parsed['host'];
-			}
-		}
-	}
-
-	if ( is_object( $wp_styles ) && ! empty( $wp_styles->registered ) ) {
-		foreach ( $wp_styles->registered as $registered_style ) {
-			$parsed = wp_parse_url( $registered_style->src );
-
-			if ( ! empty( $parsed['host'] ) && ! in_array( $parsed['host'], $unique_hosts ) && $parsed['host'] !== $_SERVER['SERVER_NAME'] ) {
-				$unique_hosts[] = $parsed['host'];
+				if ( ! empty( $parsed['host'] ) && ! in_array( $parsed['host'], $unique_hosts ) && $parsed['host'] !== $_SERVER['SERVER_NAME'] ) {
+					$unique_hosts[] = $parsed['host'];
+				}
 			}
 		}
 	}
diff --git a/wp-includes/version.php b/wp-includes/version.php
index e7bc169248..37dbed060e 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.6-beta3-38099';
+$wp_version = '4.6-beta3-38100';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.