diff -r 490d5cc509ed -r cf61fcea0001 wp/wp-includes/class-wp-http-encoding.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/class-wp-http-encoding.php	Mon Oct 14 17:39:30 2019 +0200
@@ -0,0 +1,228 @@
+<?php
+/**
+ * HTTP API: WP_Http_Encoding class
+ *
+ * @package WordPress
+ * @subpackage HTTP
+ * @since 4.4.0
+ */
+
+/**
+ * Core class used to implement deflate and gzip transfer encoding support for HTTP requests.
+ *
+ * Includes RFC 1950, RFC 1951, and RFC 1952.
+ *
+ * @since 2.8.0
+ */
+class WP_Http_Encoding {
+
+	/**
+	 * Compress raw string using the deflate format.
+	 *
+	 * Supports the RFC 1951 standard.
+	 *
+	 * @since 2.8.0
+	 *
+	 * @static
+	 *
+	 * @param string $raw String to compress.
+	 * @param int $level Optional, default is 9. Compression level, 9 is highest.
+	 * @param string $supports Optional, not used. When implemented it will choose the right compression based on what the server supports.
+	 * @return string|false False on failure.
+	 */
+	public static function compress( $raw, $level = 9, $supports = null ) {
+		return gzdeflate( $raw, $level );
+	}
+
+	/**
+	 * Decompression of deflated string.
+	 *
+	 * Will attempt to decompress using the RFC 1950 standard, and if that fails
+	 * then the RFC 1951 standard deflate will be attempted. Finally, the RFC
+	 * 1952 standard gzip decode will be attempted. If all fail, then the
+	 * original compressed string will be returned.
+	 *
+	 * @since 2.8.0
+	 *
+	 * @static
+	 *
+	 * @param string $compressed String to decompress.
+	 * @param int $length The optional length of the compressed data.
+	 * @return string|bool False on failure.
+	 */
+	public static function decompress( $compressed, $length = null ) {
+
+		if ( empty($compressed) )
+			return $compressed;
+
+		if ( false !== ( $decompressed = @gzinflate( $compressed ) ) )
+			return $decompressed;
+
+		if ( false !== ( $decompressed = self::compatible_gzinflate( $compressed ) ) )
+			return $decompressed;
+
+		if ( false !== ( $decompressed = @gzuncompress( $compressed ) ) )
+			return $decompressed;
+
+		if ( function_exists('gzdecode') ) {
+			$decompressed = @gzdecode( $compressed );
+
+			if ( false !== $decompressed )
+				return $decompressed;
+		}
+
+		return $compressed;
+	}
+
+	/**
+	 * Decompression of deflated string while staying compatible with the majority of servers.
+	 *
+	 * Certain Servers will return deflated data with headers which PHP's gzinflate()
+	 * function cannot handle out of the box. The following function has been created from
+	 * various snippets on the gzinflate() PHP documentation.
+	 *
+	 * Warning: Magic numbers within. Due to the potential different formats that the compressed
+	 * data may be returned in, some "magic offsets" are needed to ensure proper decompression
+	 * takes place. For a simple progmatic way to determine the magic offset in use, see:
+	 * https://core.trac.wordpress.org/ticket/18273
+	 *
+	 * @since 2.8.1
+	 * @link https://core.trac.wordpress.org/ticket/18273
+	 * @link https://secure.php.net/manual/en/function.gzinflate.php#70875
+	 * @link https://secure.php.net/manual/en/function.gzinflate.php#77336
+	 *
+	 * @static
+	 *
+	 * @param string $gzData String to decompress.
+	 * @return string|bool False on failure.
+	 */
+	public static function compatible_gzinflate($gzData) {
+
+		// Compressed data might contain a full header, if so strip it for gzinflate().
+		if ( substr($gzData, 0, 3) == "\x1f\x8b\x08" ) {
+			$i = 10;
+			$flg = ord( substr($gzData, 3, 1) );
+			if ( $flg > 0 ) {
+				if ( $flg & 4 ) {
+					list($xlen) = unpack('v', substr($gzData, $i, 2) );
+					$i = $i + 2 + $xlen;
+				}
+				if ( $flg & 8 )
+					$i = strpos($gzData, "\0", $i) + 1;
+				if ( $flg & 16 )
+					$i = strpos($gzData, "\0", $i) + 1;
+				if ( $flg & 2 )
+					$i = $i + 2;
+			}
+			$decompressed = @gzinflate( substr($gzData, $i, -8) );
+			if ( false !== $decompressed )
+				return $decompressed;
+		}
+
+		// Compressed data from java.util.zip.Deflater amongst others.
+		$decompressed = @gzinflate( substr($gzData, 2) );
+		if ( false !== $decompressed )
+			return $decompressed;
+
+		return false;
+	}
+
+	/**
+	 * What encoding types to accept and their priority values.
+	 *
+	 * @since 2.8.0
+	 *
+	 * @static
+	 *
+	 * @param string $url
+	 * @param array  $args
+	 * @return string Types of encoding to accept.
+	 */
+	public static function accept_encoding( $url, $args ) {
+		$type = array();
+		$compression_enabled = self::is_available();
+
+		if ( ! $args['decompress'] ) // Decompression specifically disabled.
+			$compression_enabled = false;
+		elseif ( $args['stream'] ) // Disable when streaming to file.
+			$compression_enabled = false;
+		elseif ( isset( $args['limit_response_size'] ) ) // If only partial content is being requested, we won't be able to decompress it.
+			$compression_enabled = false;
+
+		if ( $compression_enabled ) {
+			if ( function_exists( 'gzinflate' ) )
+				$type[] = 'deflate;q=1.0';
+
+			if ( function_exists( 'gzuncompress' ) )
+				$type[] = 'compress;q=0.5';
+
+			if ( function_exists( 'gzdecode' ) )
+				$type[] = 'gzip;q=0.5';
+		}
+
+		/**
+		 * Filters the allowed encoding types.
+		 *
+		 * @since 3.6.0
+		 *
+		 * @param array  $type Encoding types allowed. Accepts 'gzinflate',
+		 *                     'gzuncompress', 'gzdecode'.
+		 * @param string $url  URL of the HTTP request.
+		 * @param array  $args HTTP request arguments.
+		 */
+		$type = apply_filters( 'wp_http_accept_encoding', $type, $url, $args );
+
+		return implode(', ', $type);
+	}
+
+	/**
+	 * What encoding the content used when it was compressed to send in the headers.
+	 *
+	 * @since 2.8.0
+	 *
+	 * @static
+	 *
+	 * @return string Content-Encoding string to send in the header.
+	 */
+	public static function content_encoding() {
+		return 'deflate';
+	}
+
+	/**
+	 * Whether the content be decoded based on the headers.
+	 *
+	 * @since 2.8.0
+	 *
+	 * @static
+	 *
+	 * @param array|string $headers All of the available headers.
+	 * @return bool
+	 */
+	public static function should_decode($headers) {
+		if ( is_array( $headers ) ) {
+			if ( array_key_exists('content-encoding', $headers) && ! empty( $headers['content-encoding'] ) )
+				return true;
+		} elseif ( is_string( $headers ) ) {
+			return ( stripos($headers, 'content-encoding:') !== false );
+		}
+
+		return false;
+	}
+
+	/**
+	 * Whether decompression and compression are supported by the PHP version.
+	 *
+	 * Each function is tested instead of checking for the zlib extension, to
+	 * ensure that the functions all exist in the PHP version and aren't
+	 * disabled.
+	 *
+	 * @since 2.8.0
+	 *
+	 * @static
+	 *
+	 * @return bool
+	 */
+	public static function is_available() {
+		return ( function_exists('gzuncompress') || function_exists('gzdeflate') || function_exists('gzinflate') );
+	}
+}