Requests::compatible_gzinflate( string $gz_data ): string|bool

988	public static function compatible_gzinflate($gz_data) {989		if (is_string($gz_data) === false) {990			throw InvalidArgument::create(1, '$gz_data', 'string', gettype($gz_data));991		}992 993		if (trim($gz_data) === '') {994			return false;995		}996 997		// Compressed data might contain a full zlib header, if so strip it for998		// gzinflate()999		if (substr($gz_data, 0, 3) === "\x1f\x8b\x08") {1000			$i   = 10;1001			$flg = ord(substr($gz_data, 3, 1));1002			if ($flg > 0) {1003				if ($flg & 4) {1004					list($xlen) = unpack('v', substr($gz_data, $i, 2));1005					$i         += 2 + $xlen;1006				}1007 1008				if ($flg & 8) {1009					$i = strpos($gz_data, "\0", $i) + 1;1010				}1011 1012				if ($flg & 16) {1013					$i = strpos($gz_data, "\0", $i) + 1;1014				}1015 1016				if ($flg & 2) {1017					$i += 2;1018				}1019			}1020 1021			$decompressed = self::compatible_gzinflate(substr($gz_data, $i));1022			if ($decompressed !== false) {1023				return $decompressed;1024			}1025		}1026 1027		// If the data is Huffman Encoded, we must first strip the leading 21028		// byte Huffman marker for gzinflate()1029		// The response is Huffman coded by many compressors such as1030		// java.util.zip.Deflater, Ruby's Zlib::Deflate, and .NET's1031		// System.IO.Compression.DeflateStream.1032		//1033		// See https://decompres.blogspot.com/ for a quick explanation of this1034		// data type1035		$huffman_encoded = false;1036 1037		// low nibble of first byte should be 0x081038		list(, $first_nibble) = unpack('h', $gz_data);1039 1040		// First 2 bytes should be divisible by 0x1F1041		list(, $first_two_bytes) = unpack('n', $gz_data);1042 1043		if ($first_nibble === 0x08 && ($first_two_bytes % 0x1F) === 0) {1044			$huffman_encoded = true;1045		}1046 1047		if ($huffman_encoded) {1048			$decompressed = @gzinflate(substr($gz_data, 2));1049			if ($decompressed !== false) {1050				return $decompressed;1051			}1052		}1053 1054		if (substr($gz_data, 0, 4) === "\x50\x4b\x03\x04") {1055			// ZIP file format header1056			// Offset 6: 2 bytes, General-purpose field1057			// Offset 26: 2 bytes, filename length1058			// Offset 28: 2 bytes, optional field length1059			// Offset 30: Filename field, followed by optional field, followed1060			// immediately by data1061			list(, $general_purpose_flag) = unpack('v', substr($gz_data, 6, 2));1062 1063			// If the file has been compressed on the fly, 0x08 bit is set of1064			// the general purpose field. We can use this to differentiate1065			// between a compressed document, and a ZIP file1066			$zip_compressed_on_the_fly = ((0x08 & $general_purpose_flag) === 0x08);1067