/// <summary>
		/// Finishes the stream.  This will write the central directory at the
		/// end of the zip file and flush the stream.
		/// </summary>
		/// <remarks>
		/// This is automatically called when the stream is closed.
		/// </remarks>
		/// <exception cref="System.IO.IOException">
		/// An I/O error occurs.
		/// </exception>
		/// <exception cref="ZipException">
		/// Comment exceeds the maximum length<br/>
		/// Entry name exceeds the maximum length
		/// </exception>
		public override void Finish()
		{
			if (entries == null)  {
				return;
			}
			
			if (curEntry != null) {
				CloseEntry();
			}
			
			long numEntries = entries.Count;
			long sizeEntries = 0;
			
			foreach (ZipEntry entry in entries) {
				WriteLeInt(ZipConstants.CentralHeaderSignature); 
				WriteLeShort(ZipConstants.VersionMadeBy);
				WriteLeShort(entry.Version);
				WriteLeShort(entry.Flags);
				WriteLeShort((short)entry.CompressionMethod);
				WriteLeInt((int)entry.DosTime);
				WriteLeInt((int)entry.Crc);

				if ( entry.IsZip64Forced() || 
					(entry.CompressedSize >= uint.MaxValue) )
				{
					WriteLeInt(-1);
				}
				else {
					WriteLeInt((int)entry.CompressedSize);
				}

				if ( entry.IsZip64Forced() ||
					(entry.Size >= uint.MaxValue) )
				{
					WriteLeInt(-1);
				}
				else {
					WriteLeInt((int)entry.Size);
				}

				byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name);
				
				if (name.Length > 0xffff) {
					throw new ZipException("Name too long.");
				}
				
				ZipExtraData ed = new ZipExtraData(entry.ExtraData);

				if ( entry.CentralHeaderRequiresZip64 ) {
					ed.StartNewEntry();
					if ( entry.IsZip64Forced() ||
						(entry.Size >= 0xffffffff) )
					{
						ed.AddLeLong(entry.Size);
					}

					if ( entry.IsZip64Forced() ||
						(entry.CompressedSize >= 0xffffffff) )
					{
						ed.AddLeLong(entry.CompressedSize);
					}

					if ( entry.Offset >= 0xffffffff )
					{
						ed.AddLeLong(entry.Offset);
					}

					ed.AddNewEntry(1);
				}
				else {
					ed.Delete(1);
				}

				byte[] extra = ed.GetEntryData();
				
				byte[] entryComment = 
					(entry.Comment != null) ? 
					ZipConstants.ConvertToArray(entry.Flags, entry.Comment) :
					new byte[0];

				if (entryComment.Length > 0xffff) {
					throw new ZipException("Comment too long.");
				}
				
				WriteLeShort(name.Length);
				WriteLeShort(extra.Length);
				WriteLeShort(entryComment.Length);
				WriteLeShort(0);	// disk number
				WriteLeShort(0);	// internal file attributes
									// external file attributes

				if (entry.ExternalFileAttributes != -1) {
					WriteLeInt(entry.ExternalFileAttributes);
				} else {
					if (entry.IsDirectory) {                         // mark entry as directory (from nikolam.AT.perfectinfo.com)
						WriteLeInt(16);
					} else {
						WriteLeInt(0);
					}
				}

				if ( entry.Offset >= uint.MaxValue ) {
					WriteLeInt(-1);
				}
				else {
					WriteLeInt((int)entry.Offset);
				}
				
				if ( name.Length > 0 ) {
					baseOutputStream_.Write(name,    0, name.Length);
				}

				if ( extra.Length > 0 ) {
					baseOutputStream_.Write(extra,   0, extra.Length);
				}

				if ( entryComment.Length > 0 ) {
					baseOutputStream_.Write(entryComment, 0, entryComment.Length);
				}

				sizeEntries += ZipConstants.CentralHeaderBaseSize + name.Length + extra.Length + entryComment.Length;
			}
			
			using ( ZipHelperStream zhs = new ZipHelperStream(baseOutputStream_) ) {
				zhs.WriteEndOfCentralDirectory(numEntries, sizeEntries, offset, zipComment);
			}

			entries = null;
		}
		// Write the local file header
		// TODO: ZipHelperStream.WriteLocalHeader is not yet used and needs checking for ZipFile and ZipOuptutStream usage
		void WriteLocalHeader(ZipEntry entry, EntryPatchData patchData) 
		{
			CompressionMethod method = entry.CompressionMethod;
			bool headerInfoAvailable = true; // How to get this?
			bool patchEntryHeader = false;

			WriteLEInt(ZipConstants.LocalHeaderSignature);
			
			WriteLEShort(entry.Version);
			WriteLEShort(entry.Flags);
			WriteLEShort((byte)method);
			WriteLEInt((int)entry.DosTime);

			if (headerInfoAvailable == true) {
				WriteLEInt((int)entry.Crc);
				if ( entry.LocalHeaderRequiresZip64 ) {
					WriteLEInt(-1);
					WriteLEInt(-1);
				}
				else {
					WriteLEInt(entry.IsCrypted ? (int)entry.CompressedSize + ZipConstants.CryptoHeaderSize : (int)entry.CompressedSize);
					WriteLEInt((int)entry.Size);
				}
			} else {
				if (patchData != null) {
					patchData.CrcPatchOffset = stream_.Position;
				}
				WriteLEInt(0);	// Crc
				
				if ( patchData != null ) {
					patchData.SizePatchOffset = stream_.Position;
				}

				// For local header both sizes appear in Zip64 Extended Information
				if ( entry.LocalHeaderRequiresZip64 && patchEntryHeader ) {
					WriteLEInt(-1);
					WriteLEInt(-1);
				}
				else {
					WriteLEInt(0);	// Compressed size
					WriteLEInt(0);	// Uncompressed size
				}
			}

			byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name);
			
			if (name.Length > 0xFFFF) {
				throw new ZipException("Entry name too long.");
			}

			ZipExtraData ed = new ZipExtraData(entry.ExtraData);

			if (entry.LocalHeaderRequiresZip64 && (headerInfoAvailable || patchEntryHeader)) {
				ed.StartNewEntry();
				if (headerInfoAvailable) {
					ed.AddLeLong(entry.Size);
					ed.AddLeLong(entry.CompressedSize);
				}
				else {
					ed.AddLeLong(-1);
					ed.AddLeLong(-1);
				}
				ed.AddNewEntry(1);

				if ( !ed.Find(1) ) {
					throw new ZipException("Internal error cant find extra data");
				}
				
				if ( patchData != null ) {
					patchData.SizePatchOffset = ed.CurrentReadIndex;
				}
			}
			else {
				ed.Delete(1);
			}
			
			byte[] extra = ed.GetEntryData();

			WriteLEShort(name.Length);
			WriteLEShort(extra.Length);

			if ( name.Length > 0 ) {
				stream_.Write(name, 0, name.Length);
			}
			
			if ( entry.LocalHeaderRequiresZip64 && patchEntryHeader ) {
				patchData.SizePatchOffset += stream_.Position;
			}

			if ( extra.Length > 0 ) {
				stream_.Write(extra, 0, extra.Length);
			}
		}
		/// <summary>
		/// Starts a new Zip entry. It automatically closes the previous
		/// entry if present.
		/// All entry elements bar name are optional, but must be correct if present.
		/// If the compression method is stored and the output is not patchable
		/// the compression for that entry is automatically changed to deflate level 0
		/// </summary>
		/// <param name="entry">
		/// the entry.
		/// </param>
		/// <exception cref="System.ArgumentNullException">
		/// if entry passed is null.
		/// </exception>
		/// <exception cref="System.IO.IOException">
		/// if an I/O error occured.
		/// </exception>
		/// <exception cref="System.InvalidOperationException">
		/// if stream was finished
		/// </exception>
		/// <exception cref="ZipException">
		/// Too many entries in the Zip file<br/>
		/// Entry name is too long<br/>
		/// Finish has already been called<br/>
		/// </exception>
		public void PutNextEntry(ZipEntry entry)
		{
			if ( entry == null ) {
				throw new ArgumentNullException("entry");
			}

			if (entries == null) {
				throw new InvalidOperationException("ZipOutputStream was finished");
			}
			
			if (curEntry != null) {
				CloseEntry();
			}

			if (entries.Count == int.MaxValue) {
				throw new ZipException("Too many entries for Zip file");
			}
			
			CompressionMethod method = entry.CompressionMethod;
			int compressionLevel = defaultCompressionLevel;
			
			// Clear flags that the library manages internally
			entry.Flags &= (int)GeneralBitFlags.UnicodeText;
			patchEntryHeader = false;
			bool headerInfoAvailable = true;
			
			if (method == CompressionMethod.Stored) {
				// Cant store values in a data descriptor as you cant extract stored files
				// if the length isnt known.
				entry.Flags &= ~8;
				if (entry.CompressedSize >= 0) {
					if (entry.Size < 0) {
						entry.Size = entry.CompressedSize;
					} else if (entry.Size != entry.CompressedSize) {
						throw new ZipException("Method STORED, but compressed size != size");
					}
				} else {
					if (entry.Size >= 0) {
						entry.CompressedSize = entry.Size;
					}
				}
					
				if (entry.Size < 0 || entry.Crc < 0) {
					if (CanPatchEntries == true) {
						headerInfoAvailable = false;
					}
					else {
						// Can't patch entries so storing is not possible.
						method = CompressionMethod.Deflated;
						compressionLevel = 0;
					}
				}
			}
				
			if (method == CompressionMethod.Deflated) {
				if (entry.Size == 0) {
					// No need to compress - no data.
					entry.CompressedSize = entry.Size;
					entry.Crc = 0;
					method = CompressionMethod.Stored;
				} else if ( (entry.CompressedSize < 0) || (entry.Size < 0) || (entry.Crc < 0) ) {
					headerInfoAvailable = false;
				}
			}
			
			if (headerInfoAvailable == false) {
				if (CanPatchEntries == false) {
					// Only way to record size and compressed size is to append a data descriptor
					// after compressed data.
					entry.Flags |= 8;
				} else {
					patchEntryHeader = true;
				}
			}
			
			if (Password != null) {
				entry.IsCrypted = true;
				if (entry.Crc < 0) {
					// Need to append a data descriptor as the crc isnt available for use
					// with encryption, the date is used instead.  Setting the flag
					// indicates this to the decompressor.
					entry.Flags |= 8;
				}
			}

			entry.Offset = offset;
			entry.CompressionMethod = (CompressionMethod)method;
			
			curMethod = method;
			sizePatchPos = -1;
			
			if ( (useZip64_ == UseZip64.On) || ((entry.Size < 0) && (useZip64_ == UseZip64.Dynamic)) ) {
				entry.ForceZip64();
			}

			// Write the local file header
			WriteLeInt(ZipConstants.LocalHeaderSignature);
			
			WriteLeShort(entry.Version);
			WriteLeShort(entry.Flags);
			WriteLeShort((byte)method);
			WriteLeInt((int)entry.DosTime);

			// TODO: Refactor header writing.  Its done in several places.
			if (headerInfoAvailable == true) {
				WriteLeInt((int)entry.Crc);
				if ( entry.LocalHeaderRequiresZip64 ) {
					WriteLeInt(-1);
					WriteLeInt(-1);
				}
				else {
					WriteLeInt(entry.IsCrypted ? (int)entry.CompressedSize + ZipConstants.CryptoHeaderSize : (int)entry.CompressedSize);
					WriteLeInt((int)entry.Size);
				}
			} else {
				if (patchEntryHeader == true) {
					crcPatchPos = baseOutputStream_.Position;
				}
				WriteLeInt(0);	// Crc
				
				if ( patchEntryHeader ) {
					sizePatchPos = baseOutputStream_.Position;
				}

				// For local header both sizes appear in Zip64 Extended Information
				if ( entry.LocalHeaderRequiresZip64 && patchEntryHeader ) {
					WriteLeInt(-1);
					WriteLeInt(-1);
				}
				else {
					WriteLeInt(0);	// Compressed size
					WriteLeInt(0);	// Uncompressed size
				}
			}

			byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name);
			
			if (name.Length > 0xFFFF) {
				throw new ZipException("Entry name too long.");
			}

			ZipExtraData ed = new ZipExtraData(entry.ExtraData);

			if (entry.LocalHeaderRequiresZip64 && (headerInfoAvailable || patchEntryHeader)) {
				ed.StartNewEntry();
				if (headerInfoAvailable) {
					ed.AddLeLong(entry.Size);
					ed.AddLeLong(entry.CompressedSize);
				}
				else {
					ed.AddLeLong(-1);
					ed.AddLeLong(-1);
				}
				ed.AddNewEntry(1);

				if ( !ed.Find(1) ) {
					throw new ZipException("Internal error cant find extra data");
				}
				
				if ( patchEntryHeader ) {
					sizePatchPos = ed.CurrentReadIndex;
				}
			}
			else {
				ed.Delete(1);
			}
			
			byte[] extra = ed.GetEntryData();

			WriteLeShort(name.Length);
			WriteLeShort(extra.Length);

			if ( name.Length > 0 ) {
				baseOutputStream_.Write(name, 0, name.Length);
			}
			
			if ( entry.LocalHeaderRequiresZip64 && patchEntryHeader ) {
				sizePatchPos += baseOutputStream_.Position;
			}

			if ( extra.Length > 0 ) {
				baseOutputStream_.Write(extra, 0, extra.Length);
			}
			
			offset += ZipConstants.LocalHeaderBaseSize + name.Length + extra.Length;
			
			// Activate the entry.
			curEntry = entry;
			crc.Reset();
			if (method == CompressionMethod.Deflated) {
				deflater_.Reset();
				deflater_.SetLevel(compressionLevel);
			}
			size = 0;
			
			if (entry.IsCrypted == true) {
				if (entry.Crc < 0) {			// so testing Zip will says its ok
					WriteEncryptionHeader(entry.DosTime << 16);
				} else {
					WriteEncryptionHeader(entry.Crc);
				}
			}
		}
        /// <summary>
        /// Finishes the stream.  This will write the central directory at the
        /// end of the zip file and flush the stream.
        /// </summary>
        /// <remarks>
        /// This is automatically called when the stream is closed.
        /// </remarks>
        /// <exception cref="System.IO.IOException">
        /// An I/O error occurs.
        /// </exception>
        /// <exception cref="ZipException">
        /// Comment exceeds the maximum length<br/>
        /// Entry name exceeds the maximum length
        /// </exception>
        public override void Finish()
        {
            if (entries == null)
            {
                return;
            }

            if (curEntry != null)
            {
                CloseEntry();
            }

            long numEntries  = entries.Count;
            long sizeEntries = 0;

            foreach (ZipEntry entry in entries)
            {
                WriteLeInt(ZipConstants.CentralHeaderSignature);
                WriteLeShort(ZipConstants.VersionMadeBy);
                WriteLeShort(entry.Version);
                WriteLeShort(entry.Flags);
                WriteLeShort((short)entry.CompressionMethod);
                WriteLeInt((int)entry.DosTime);
                WriteLeInt((int)entry.Crc);

                if (entry.IsZip64Forced() ||
                    (entry.CompressedSize >= uint.MaxValue))
                {
                    WriteLeInt(-1);
                }
                else
                {
                    WriteLeInt((int)entry.CompressedSize);
                }

                if (entry.IsZip64Forced() ||
                    (entry.Size >= uint.MaxValue))
                {
                    WriteLeInt(-1);
                }
                else
                {
                    WriteLeInt((int)entry.Size);
                }

                byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name);

                if (name.Length > 0xffff)
                {
                    throw new ZipException("Name too long.");
                }

                ZipExtraData ed = new ZipExtraData(entry.ExtraData);

                if (entry.CentralHeaderRequiresZip64)
                {
                    ed.StartNewEntry();
                    if (entry.IsZip64Forced() ||
                        (entry.Size >= 0xffffffff))
                    {
                        ed.AddLeLong(entry.Size);
                    }

                    if (entry.IsZip64Forced() ||
                        (entry.CompressedSize >= 0xffffffff))
                    {
                        ed.AddLeLong(entry.CompressedSize);
                    }

                    if (entry.Offset >= 0xffffffff)
                    {
                        ed.AddLeLong(entry.Offset);
                    }

                    ed.AddNewEntry(1);
                }
                else
                {
                    ed.Delete(1);
                }

                byte[] extra = ed.GetEntryData();

                byte[] entryComment =
                    (entry.Comment != null) ?
                    ZipConstants.ConvertToArray(entry.Flags, entry.Comment) :
                    new byte[0];

                if (entryComment.Length > 0xffff)
                {
                    throw new ZipException("Comment too long.");
                }

                WriteLeShort(name.Length);
                WriteLeShort(extra.Length);
                WriteLeShort(entryComment.Length);
                WriteLeShort(0);                        // disk number
                WriteLeShort(0);                        // internal file attributes
                // external file attributes

                if (entry.ExternalFileAttributes != -1)
                {
                    WriteLeInt(entry.ExternalFileAttributes);
                }
                else
                {
                    if (entry.IsDirectory)                                               // mark entry as directory (from nikolam.AT.perfectinfo.com)
                    {
                        WriteLeInt(16);
                    }
                    else
                    {
                        WriteLeInt(0);
                    }
                }

                if (entry.Offset >= uint.MaxValue)
                {
                    WriteLeInt(-1);
                }
                else
                {
                    WriteLeInt((int)entry.Offset);
                }

                if (name.Length > 0)
                {
                    baseOutputStream_.Write(name, 0, name.Length);
                }

                if (extra.Length > 0)
                {
                    baseOutputStream_.Write(extra, 0, extra.Length);
                }

                if (entryComment.Length > 0)
                {
                    baseOutputStream_.Write(entryComment, 0, entryComment.Length);
                }

                sizeEntries += ZipConstants.CentralHeaderBaseSize + name.Length + extra.Length + entryComment.Length;
            }

            using (ZipHelperStream zhs = new ZipHelperStream(baseOutputStream_)) {
                zhs.WriteEndOfCentralDirectory(numEntries, sizeEntries, offset, zipComment);
            }

            entries = null;
        }
        /// <summary>
        /// Starts a new Zip entry. It automatically closes the previous
        /// entry if present.
        /// All entry elements bar name are optional, but must be correct if present.
        /// If the compression method is stored and the output is not patchable
        /// the compression for that entry is automatically changed to deflate level 0
        /// </summary>
        /// <param name="entry">
        /// the entry.
        /// </param>
        /// <exception cref="System.ArgumentNullException">
        /// if entry passed is null.
        /// </exception>
        /// <exception cref="System.IO.IOException">
        /// if an I/O error occured.
        /// </exception>
        /// <exception cref="System.InvalidOperationException">
        /// if stream was finished
        /// </exception>
        /// <exception cref="ZipException">
        /// Too many entries in the Zip file<br/>
        /// Entry name is too long<br/>
        /// Finish has already been called<br/>
        /// </exception>
        public void PutNextEntry(ZipEntry entry)
        {
            if (entry == null)
            {
                throw new ArgumentNullException("entry");
            }

            if (entries == null)
            {
                throw new InvalidOperationException("ZipOutputStream was finished");
            }

            if (curEntry != null)
            {
                CloseEntry();
            }

            if (entries.Count == int.MaxValue)
            {
                throw new ZipException("Too many entries for Zip file");
            }

            CompressionMethod method = entry.CompressionMethod;
            int compressionLevel     = defaultCompressionLevel;

            // Clear flags that the library manages internally
            entry.Flags     &= (int)GeneralBitFlags.UnicodeText;
            patchEntryHeader = false;
            bool headerInfoAvailable = true;

            if (method == CompressionMethod.Stored)
            {
                // Cant store values in a data descriptor as you cant extract stored files
                // if the length isnt known.
                entry.Flags &= ~8;
                if (entry.CompressedSize >= 0)
                {
                    if (entry.Size < 0)
                    {
                        entry.Size = entry.CompressedSize;
                    }
                    else if (entry.Size != entry.CompressedSize)
                    {
                        throw new ZipException("Method STORED, but compressed size != size");
                    }
                }
                else
                {
                    if (entry.Size >= 0)
                    {
                        entry.CompressedSize = entry.Size;
                    }
                }

                if (entry.Size < 0 || entry.Crc < 0)
                {
                    if (CanPatchEntries == true)
                    {
                        headerInfoAvailable = false;
                    }
                    else
                    {
                        // Can't patch entries so storing is not possible.
                        method           = CompressionMethod.Deflated;
                        compressionLevel = 0;
                    }
                }
            }

            if (method == CompressionMethod.Deflated)
            {
                if (entry.Size == 0)
                {
                    // No need to compress - no data.
                    entry.CompressedSize = entry.Size;
                    entry.Crc            = 0;
                    method = CompressionMethod.Stored;
                }
                else if ((entry.CompressedSize < 0) || (entry.Size < 0) || (entry.Crc < 0))
                {
                    headerInfoAvailable = false;
                }
            }

            if (headerInfoAvailable == false)
            {
                if (CanPatchEntries == false)
                {
                    // Only way to record size and compressed size is to append a data descriptor
                    // after compressed data.
                    entry.Flags |= 8;
                }
                else
                {
                    patchEntryHeader = true;
                }
            }

            if (Password != null)
            {
                entry.IsCrypted = true;
                if (entry.Crc < 0)
                {
                    // Need to append a data descriptor as the crc isnt available for use
                    // with encryption, the date is used instead.  Setting the flag
                    // indicates this to the decompressor.
                    entry.Flags |= 8;
                }
            }

            entry.Offset            = offset;
            entry.CompressionMethod = (CompressionMethod)method;

            curMethod    = method;
            sizePatchPos = -1;

            if ((useZip64_ == UseZip64.On) || ((entry.Size < 0) && (useZip64_ == UseZip64.Dynamic)))
            {
                entry.ForceZip64();
            }

            // Write the local file header
            WriteLeInt(ZipConstants.LocalHeaderSignature);

            WriteLeShort(entry.Version);
            WriteLeShort(entry.Flags);
            WriteLeShort((byte)method);
            WriteLeInt((int)entry.DosTime);

            // TODO: Refactor header writing.  Its done in several places.
            if (headerInfoAvailable == true)
            {
                WriteLeInt((int)entry.Crc);
                if (entry.LocalHeaderRequiresZip64)
                {
                    WriteLeInt(-1);
                    WriteLeInt(-1);
                }
                else
                {
                    WriteLeInt(entry.IsCrypted ? (int)entry.CompressedSize + ZipConstants.CryptoHeaderSize : (int)entry.CompressedSize);
                    WriteLeInt((int)entry.Size);
                }
            }
            else
            {
                if (patchEntryHeader == true)
                {
                    crcPatchPos = baseOutputStream_.Position;
                }
                WriteLeInt(0);                  // Crc

                if (patchEntryHeader)
                {
                    sizePatchPos = baseOutputStream_.Position;
                }

                // For local header both sizes appear in Zip64 Extended Information
                if (entry.LocalHeaderRequiresZip64 && patchEntryHeader)
                {
                    WriteLeInt(-1);
                    WriteLeInt(-1);
                }
                else
                {
                    WriteLeInt(0);                      // Compressed size
                    WriteLeInt(0);                      // Uncompressed size
                }
            }

            byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name);

            if (name.Length > 0xFFFF)
            {
                throw new ZipException("Entry name too long.");
            }

            ZipExtraData ed = new ZipExtraData(entry.ExtraData);

            if (entry.LocalHeaderRequiresZip64 && (headerInfoAvailable || patchEntryHeader))
            {
                ed.StartNewEntry();
                if (headerInfoAvailable)
                {
                    ed.AddLeLong(entry.Size);
                    ed.AddLeLong(entry.CompressedSize);
                }
                else
                {
                    ed.AddLeLong(-1);
                    ed.AddLeLong(-1);
                }
                ed.AddNewEntry(1);

                if (!ed.Find(1))
                {
                    throw new ZipException("Internal error cant find extra data");
                }

                if (patchEntryHeader)
                {
                    sizePatchPos = ed.CurrentReadIndex;
                }
            }
            else
            {
                ed.Delete(1);
            }

            byte[] extra = ed.GetEntryData();

            WriteLeShort(name.Length);
            WriteLeShort(extra.Length);

            if (name.Length > 0)
            {
                baseOutputStream_.Write(name, 0, name.Length);
            }

            if (entry.LocalHeaderRequiresZip64 && patchEntryHeader)
            {
                sizePatchPos += baseOutputStream_.Position;
            }

            if (extra.Length > 0)
            {
                baseOutputStream_.Write(extra, 0, extra.Length);
            }

            offset += ZipConstants.LocalHeaderBaseSize + name.Length + extra.Length;

            // Activate the entry.
            curEntry = entry;
            crc.Reset();
            if (method == CompressionMethod.Deflated)
            {
                deflater_.Reset();
                deflater_.SetLevel(compressionLevel);
            }
            size = 0;

            if (entry.IsCrypted == true)
            {
                if (entry.Crc < 0)                                      // so testing Zip will says its ok
                {
                    WriteEncryptionHeader(entry.DosTime << 16);
                }
                else
                {
                    WriteEncryptionHeader(entry.Crc);
                }
            }
        }
		int WriteCentralDirectoryHeader(ZipEntry entry)
		{
			if ( entry.CompressedSize < 0 ) {
				throw new ZipException("Attempt to write central directory entry with unknown csize");
			}

			if ( entry.Size < 0 ) {
				throw new ZipException("Attempt to write central directory entry with unknown size");
			}
			
			if ( entry.Crc < 0 ) {
				throw new ZipException("Attempt to write central directory entry with unknown crc");
			}
			
			// Write the central file header
			WriteLEInt(ZipConstants.CentralHeaderSignature);

			// Version made by
			WriteLEShort(ZipConstants.VersionMadeBy);

			// Version required to extract
			WriteLEShort(entry.Version);

			WriteLEShort(entry.Flags);
			
			unchecked {
				WriteLEShort((byte)entry.CompressionMethod);
				WriteLEInt((int)entry.DosTime);
				WriteLEInt((int)entry.Crc);
			}

			if ( (entry.IsZip64Forced()) || (entry.CompressedSize >= 0xffffffff) ) {
				WriteLEInt(-1);
			}
			else {
				WriteLEInt((int)(entry.CompressedSize & 0xffffffff));
			}

			if ( (entry.IsZip64Forced()) || (entry.Size >= 0xffffffff) ) {
				WriteLEInt(-1);
			}
			else {
				WriteLEInt((int)entry.Size);
			}

			byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name);

			if ( name.Length > 0xFFFF ) {
				throw new ZipException("Entry name is too long.");
			}

			WriteLEShort(name.Length);

			// Central header extra data is different to local header version so regenerate.
			ZipExtraData ed = new ZipExtraData(entry.ExtraData);

			if ( entry.CentralHeaderRequiresZip64 ) {
				ed.StartNewEntry();

				if ( (entry.Size >= 0xffffffff) || (useZip64_ == UseZip64.On) )
				{
					ed.AddLeLong(entry.Size);
				}

				if ( (entry.CompressedSize >= 0xffffffff) || (useZip64_ == UseZip64.On) )
				{
					ed.AddLeLong(entry.CompressedSize);
				}

				if ( entry.Offset >= 0xffffffff ) {
					ed.AddLeLong(entry.Offset);
				}

				// Number of disk on which this file starts isnt supported and is never written here.
				ed.AddNewEntry(1);
			}
			else {
				// Should have already be done when local header was added.
				ed.Delete(1);
			}

			byte[] centralExtraData = ed.GetEntryData();

			WriteLEShort(centralExtraData.Length);
			WriteLEShort(entry.Comment != null ? entry.Comment.Length : 0);

			WriteLEShort(0);	// disk number
			WriteLEShort(0);	// internal file attributes

			// External file attributes...
			if ( entry.ExternalFileAttributes != -1 ) {
				WriteLEInt(entry.ExternalFileAttributes);
			}
			else {
				if ( entry.IsDirectory ) {
					WriteLEUint(16);
				}
				else {
					WriteLEUint(0);
				}
			}

			if ( entry.Offset >= 0xffffffff ) {
				WriteLEUint(0xffffffff);
			}
			else {
				WriteLEUint((uint)(int)entry.Offset);
			}

			if ( name.Length > 0 ) {
				baseStream_.Write(name, 0, name.Length);
			}

			if ( centralExtraData.Length > 0 ) {
				baseStream_.Write(centralExtraData, 0, centralExtraData.Length);
			}

			byte[] rawComment = (entry.Comment != null) ? Encoding.ASCII.GetBytes(entry.Comment) : new byte[0];

			if ( rawComment.Length > 0 ) {
				baseStream_.Write(rawComment, 0, rawComment.Length);
			}

			return ZipConstants.CentralHeaderBaseSize + name.Length + centralExtraData.Length + rawComment.Length;
		}
		void WriteLocalEntryHeader(ZipUpdate update)
		{
			ZipEntry entry = update.OutEntry;

			// TODO: Local offset will require adjusting for multi-disk zip files.
			entry.Offset = baseStream_.Position;

			// TODO: Need to clear any entry flags that dont make sense or throw an exception here.
			if (update.Command != UpdateCommand.Copy) {
				if (entry.CompressionMethod == CompressionMethod.Deflated) {
					if (entry.Size == 0) {
						// No need to compress - no data.
						entry.CompressedSize = entry.Size;
						entry.Crc = 0;
						entry.CompressionMethod = CompressionMethod.Stored;
					}
				}
				else if (entry.CompressionMethod == CompressionMethod.Stored) {
					entry.Flags &= ~(int)GeneralBitFlags.Descriptor;
				}

				if (HaveKeys) {
					entry.IsCrypted = true;
					if (entry.Crc < 0) {
						entry.Flags |= (int)GeneralBitFlags.Descriptor;
					}
				}
				else {
					entry.IsCrypted = false;
				}

				switch (useZip64_) {
					case UseZip64.Dynamic:
						if (entry.Size < 0) {
							entry.ForceZip64();
						}
						break;

					case UseZip64.On:
						entry.ForceZip64();
						break;

					case UseZip64.Off:
						// Do nothing.  The entry itself may be using Zip64 independantly.
						break;
				}
			}

			// Write the local file header
			WriteLEInt(ZipConstants.LocalHeaderSignature);

			WriteLEShort(entry.Version);
			WriteLEShort(entry.Flags);

			WriteLEShort((byte)entry.CompressionMethod);
			WriteLEInt(( int )entry.DosTime);

			if ( !entry.HasCrc ) {
				// Note patch address for updating CRC later.
				update.CrcPatchOffset = baseStream_.Position;
				WriteLEInt(( int )0);
			}
			else {
				WriteLEInt(unchecked(( int )entry.Crc));
			}

			if (entry.LocalHeaderRequiresZip64) {
				WriteLEInt(-1);
				WriteLEInt(-1);
			}
			else {
				if ( (entry.CompressedSize < 0) || (entry.Size < 0) ) {
					update.SizePatchOffset = baseStream_.Position;
				}

				WriteLEInt(( int )entry.CompressedSize);
				WriteLEInt(( int )entry.Size);
			}

			byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name);

			if ( name.Length > 0xFFFF ) {
				throw new ZipException("Entry name too long.");
			}

			ZipExtraData ed = new ZipExtraData(entry.ExtraData);

			if ( entry.LocalHeaderRequiresZip64 ) {
				ed.StartNewEntry();

				// Local entry header always includes size and compressed size.
				// NOTE the order of these fields is reversed when compared to the normal headers!
				ed.AddLeLong(entry.Size);
				ed.AddLeLong(entry.CompressedSize);
				ed.AddNewEntry(1);
			}
			else {
				ed.Delete(1);
			}

			entry.ExtraData = ed.GetEntryData();

			WriteLEShort(name.Length);
			WriteLEShort(entry.ExtraData.Length);

			if ( name.Length > 0 ) {
				baseStream_.Write(name, 0, name.Length);
			}

			if ( entry.LocalHeaderRequiresZip64 ) {
				if ( !ed.Find(1) ) {
					throw new ZipException("Internal error cannot find extra data");
				}

				update.SizePatchOffset = baseStream_.Position + ed.CurrentReadIndex;
			}

			if ( entry.ExtraData.Length > 0 ) {
				baseStream_.Write(entry.ExtraData, 0, entry.ExtraData.Length);
			}
		}
        // Write the local file header
        // TODO: ZipHelperStream.WriteLocalHeader is not yet used and needs checking for ZipFile and ZipOuptutStream usage
        void WriteLocalHeader(ZipEntry entry, EntryPatchData patchData)
        {
            CompressionMethod method = entry.CompressionMethod;
            bool headerInfoAvailable = true;             // How to get this?
            bool patchEntryHeader    = false;

            WriteLEInt(ZipConstants.LocalHeaderSignature);

            WriteLEShort(entry.Version);
            WriteLEShort(entry.Flags);
            WriteLEShort((byte)method);
            WriteLEInt((int)entry.DosTime);

            if (headerInfoAvailable == true)
            {
                WriteLEInt((int)entry.Crc);
                if (entry.LocalHeaderRequiresZip64)
                {
                    WriteLEInt(-1);
                    WriteLEInt(-1);
                }
                else
                {
                    WriteLEInt(entry.IsCrypted ? (int)entry.CompressedSize + ZipConstants.CryptoHeaderSize : (int)entry.CompressedSize);
                    WriteLEInt((int)entry.Size);
                }
            }
            else
            {
                if (patchData != null)
                {
                    patchData.CrcPatchOffset = stream_.Position;
                }
                WriteLEInt(0);                  // Crc

                if (patchData != null)
                {
                    patchData.SizePatchOffset = stream_.Position;
                }

                // For local header both sizes appear in Zip64 Extended Information
                if (entry.LocalHeaderRequiresZip64 && patchEntryHeader)
                {
                    WriteLEInt(-1);
                    WriteLEInt(-1);
                }
                else
                {
                    WriteLEInt(0);                      // Compressed size
                    WriteLEInt(0);                      // Uncompressed size
                }
            }

            byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name);

            if (name.Length > 0xFFFF)
            {
                throw new ZipException("Entry name too long.");
            }

            ZipExtraData ed = new ZipExtraData(entry.ExtraData);

            if (entry.LocalHeaderRequiresZip64 && (headerInfoAvailable || patchEntryHeader))
            {
                ed.StartNewEntry();
                if (headerInfoAvailable)
                {
                    ed.AddLeLong(entry.Size);
                    ed.AddLeLong(entry.CompressedSize);
                }
                else
                {
                    ed.AddLeLong(-1);
                    ed.AddLeLong(-1);
                }
                ed.AddNewEntry(1);

                if (!ed.Find(1))
                {
                    throw new ZipException("Internal error cant find extra data");
                }

                if (patchData != null)
                {
                    patchData.SizePatchOffset = ed.CurrentReadIndex;
                }
            }
            else
            {
                ed.Delete(1);
            }

            byte[] extra = ed.GetEntryData();

            WriteLEShort(name.Length);
            WriteLEShort(extra.Length);

            if (name.Length > 0)
            {
                stream_.Write(name, 0, name.Length);
            }

            if (entry.LocalHeaderRequiresZip64 && patchEntryHeader)
            {
                patchData.SizePatchOffset += stream_.Position;
            }

            if (extra.Length > 0)
            {
                stream_.Write(extra, 0, extra.Length);
            }
        }