From e5f967ca997abbc971f697fad33e74396848dc28 Mon Sep 17 00:00:00 2001
From: Dominik Schilling <dominikschilling+git@gmail.com>
Date: Tue, 12 Jul 2016 11:32:28 +0000
Subject: [PATCH] Resource Hints: Remove schemes from `dns-prefetch` resource
 hint outputs.

"wordpress.org", "!http://wordpress.org", and "!https://wordpress.org" should all have the same DNS lookup.
Also, replace `\r\n` with `\n` and ensure that invalid URLs are skipped.

Props niallkennedy, peterwilsoncc.
Fixes #37240.
Built from https://develop.svn.wordpress.org/trunk@38036


git-svn-id: http://core.svn.wordpress.org/trunk@37977 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/general-template.php | 20 ++++++++++++++++----
 wp-includes/version.php          |  2 +-
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/wp-includes/general-template.php b/wp-includes/general-template.php
index bf0614bd22..2bcdb43801 100644
--- a/wp-includes/general-template.php
+++ b/wp-includes/general-template.php
@@ -2815,25 +2815,37 @@ function wp_resource_hints() {
 		 * @param string $relation_type The relation type the URLs are printed for, e.g. 'preconnect' or 'prerender'.
 		 */
 		$urls = apply_filters( 'wp_resource_hints', $urls, $relation_type );
-		$urls = array_unique( $urls );
 
-		foreach ( $urls as $url ) {
+		foreach ( $urls as $key => $url ) {
 			$url = esc_url( $url, array( 'http', 'https' ) );
+			if ( ! $url ) {
+				unset( $urls[ $key ] );
+				continue;
+			}
 
 			if ( in_array( $relation_type, array( 'preconnect', 'dns-prefetch' ) ) ) {
 				$parsed = wp_parse_url( $url );
 				if ( empty( $parsed['host'] ) ) {
+					unset( $urls[ $key ] );
 					continue;
 				}
 
-				if ( ! empty( $parsed['scheme'] ) ) {
+				if ( 'dns-prefetch' === $relation_type ) {
+					$url = '//' . $parsed['host'];
+				} else if ( ! empty( $parsed['scheme'] ) ) {
 					$url = $parsed['scheme'] . '://' . $parsed['host'];
 				} else {
 					$url = $parsed['host'];
 				}
 			}
 
-			printf( "<link rel='%s' href='%s'>\r\n", $relation_type, $url );
+			$urls[ $key ] = $url;
+		}
+
+		$urls = array_unique( $urls );
+
+		foreach ( $urls as $url ) {
+			printf( "<link rel='%s' href='%s'>\n", $relation_type, $url );
 		}
 	}
 }
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 862ff25ef9..bf34f2e8cc 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.6-beta2-38035';
+$wp_version = '4.6-beta2-38036';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.