diff --git a/wp-includes/class-http.php b/wp-includes/class-http.php
index cd8bbef981..a68711c8cd 100644
--- a/wp-includes/class-http.php
+++ b/wp-includes/class-http.php
@@ -346,7 +346,7 @@ class WP_Http {
 	 * @return array Processed string headers. If duplicate headers are encountered,
 	 * 					Then a numbered array is returned as the value of that header-key.
 	 */
-	function processHeaders($headers) {
+	public static function processHeaders($headers) {
 		// split headers, one per array element
 		if ( is_string($headers) ) {
 			// tolerate line terminator: CRLF = LF (RFC 2616 19.3)
@@ -413,7 +413,7 @@ class WP_Http {
 	 *
 	 * @param array $r Full array of args passed into ::request()
 	 */
-	function buildCookieHeader( &$r ) {
+	public static function buildCookieHeader( &$r ) {
 		if ( ! empty($r['cookies']) ) {
 			$cookies_header = '';
 			foreach ( (array) $r['cookies'] as $cookie ) {
@@ -756,7 +756,7 @@ class WP_Http_Fsockopen {
 	 * @static
 	 * @return boolean False means this class can not be used, true means it can.
 	 */
-	function test( $args = array() ) {
+	public static function test( $args = array() ) {
 		if ( ! function_exists( 'fsockopen' ) )
 			return false;
 
@@ -939,7 +939,7 @@ class WP_Http_Streams {
 	 *
 	 * @return boolean False means this class can not be used, true means it can.
 	 */
-	function test( $args = array() ) {
+	public static function test( $args = array() ) {
 		if ( ! function_exists( 'fopen' ) )
 			return false;
 
@@ -1166,7 +1166,7 @@ class WP_Http_Curl {
 	 *
 	 * @return boolean False means this class can not be used, true means it can.
 	 */
-	function test( $args = array() ) {
+	public static function test( $args = array() ) {
 		if ( ! function_exists( 'curl_init' ) || ! function_exists( 'curl_exec' ) )
 			return false;
 
@@ -1580,7 +1580,7 @@ class WP_Http_Encoding {
 	 * @param string $supports Optional, not used. When implemented it will choose the right compression based on what the server supports.
 	 * @return string|bool False on failure.
 	 */
-	function compress( $raw, $level = 9, $supports = null ) {
+	public static function compress( $raw, $level = 9, $supports = null ) {
 		return gzdeflate( $raw, $level );
 	}
 
@@ -1598,7 +1598,7 @@ class WP_Http_Encoding {
 	 * @param int $length The optional length of the compressed data.
 	 * @return string|bool False on failure.
 	 */
-	function decompress( $compressed, $length = null ) {
+	public static function decompress( $compressed, $length = null ) {
 
 		if ( empty($compressed) )
 			return $compressed;
@@ -1642,7 +1642,7 @@ class WP_Http_Encoding {
 	 * @param string $gzData String to decompress.
 	 * @return string|bool False on failure.
 	 */
-	function compatible_gzinflate($gzData) {
+	public static function compatible_gzinflate($gzData) {
 
 		// Compressed data might contain a full header, if so strip it for gzinflate()
 		if ( substr($gzData, 0, 3) == "\x1f\x8b\x08" ) {
@@ -1680,7 +1680,7 @@ class WP_Http_Encoding {
 	 *
 	 * @return string Types of encoding to accept.
 	 */
-	function accept_encoding() {
+	public static function accept_encoding() {
 		$type = array();
 		if ( function_exists( 'gzinflate' ) )
 			$type[] = 'deflate;q=1.0';
@@ -1701,7 +1701,7 @@ class WP_Http_Encoding {
 	 *
 	 * @return string Content-Encoding string to send in the header.
 	 */
-	function content_encoding() {
+	public static function content_encoding() {
 		return 'deflate';
 	}
 
@@ -1713,7 +1713,7 @@ class WP_Http_Encoding {
 	 * @param array|string $headers All of the available headers.
 	 * @return bool
 	 */
-	function should_decode($headers) {
+	public static function should_decode($headers) {
 		if ( is_array( $headers ) ) {
 			if ( array_key_exists('content-encoding', $headers) && ! empty( $headers['content-encoding'] ) )
 				return true;
@@ -1735,7 +1735,7 @@ class WP_Http_Encoding {
 	 *
 	 * @return bool
 	 */
-	function is_available() {
+	public static function is_available() {
 		return ( function_exists('gzuncompress') || function_exists('gzdeflate') || function_exists('gzinflate') );
 	}
 }
diff --git a/wp-includes/class-wp.php b/wp-includes/class-wp.php
index d136f08885..1540423929 100644
--- a/wp-includes/class-wp.php
+++ b/wp-includes/class-wp.php
@@ -572,7 +572,7 @@ class WP_MatchesMapRegex {
 	 * @param array  $matches data used for substitution
 	 * @return string
 	 */
-	function apply($subject, $matches) {
+	public static function apply($subject, $matches) {
 		$oSelf = new WP_MatchesMapRegex($subject, $matches);
 		return $oSelf->output;
 	}
diff --git a/wp-includes/general-template.php b/wp-includes/general-template.php
index b09d2fe8e3..e875422898 100644
--- a/wp-includes/general-template.php
+++ b/wp-includes/general-template.php
@@ -1621,7 +1621,8 @@ function feed_links_extra( $args = array() ) {
 	$args = wp_parse_args( $args, $defaults );
 
 	if ( is_single() || is_page() ) {
-		$post = &get_post( $id = 0 );
+		$id = 0;
+		$post = &get_post( $id );
 
 		if ( comments_open() || pings_open() || $post->comment_count > 0 ) {
 			$title = esc_attr(sprintf( $args['singletitle'], get_bloginfo('name'), $args['separator'], esc_html( get_the_title() ) ));
diff --git a/wp-includes/ms-load.php b/wp-includes/ms-load.php
index 797d606110..3343903810 100644
--- a/wp-includes/ms-load.php
+++ b/wp-includes/ms-load.php
@@ -134,6 +134,10 @@ function get_current_site_name( $current_site ) {
  */
 function wpmu_current_site() {
 	global $wpdb, $current_site, $domain, $path, $sites, $cookie_domain;
+
+	if ( empty( $current_site ) )
+		$current_site = new stdClass;
+
 	if ( defined( 'DOMAIN_CURRENT_SITE' ) && defined( 'PATH_CURRENT_SITE' ) ) {
 		$current_site->id = defined( 'SITE_ID_CURRENT_SITE' ) ? SITE_ID_CURRENT_SITE : 1;
 		$current_site->domain = DOMAIN_CURRENT_SITE;
diff --git a/wp-includes/post.php b/wp-includes/post.php
index 4ab61c2b7d..19472912d1 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -4027,7 +4027,8 @@ function wp_mime_type_icon( $mime = 0 ) {
 			$dirs = apply_filters( 'icon_dirs', array($icon_dir => $icon_dir_uri) );
 			$icon_files = array();
 			while ( $dirs ) {
-				$dir = array_shift($keys = array_keys($dirs));
+				$keys = array_keys( $dirs );
+				$dir = array_shift( $keys );
 				$uri = array_shift($dirs);
 				if ( $dh = opendir($dir) ) {
 					while ( false !== $file = readdir($dh) ) {