// build the TOC by reading each entry in the file.
        private static void ReadIntoInstance_Orig(ZipFile zf)
        {
            zf.OnReadStarted();
            //zf._entries = new System.Collections.Generic.List<ZipEntry>();
            zf._entries = new System.Collections.Generic.Dictionary <String, ZipEntry>();

            ZipEntry e;

            if (zf.Verbose)
            {
                if (zf.Name == null)
                {
                    zf.StatusMessageTextWriter.WriteLine("Reading zip from stream...");
                }
                else
                {
                    zf.StatusMessageTextWriter.WriteLine("Reading zip {0}...", zf.Name);
                }
            }

            // work item 6647:  PK00 (packed to removable disk)
            bool         firstEntry = true;
            ZipContainer zc         = new ZipContainer(zf);

            while ((e = ZipEntry.ReadEntry(zc, firstEntry)) != null)
            {
                if (zf.Verbose)
                {
                    zf.StatusMessageTextWriter.WriteLine("  {0}", e.FileName);
                }

                zf._entries.Add(e.FileName, e);
                firstEntry = false;
            }

            // read the zipfile's central directory structure here.
            // workitem 9912
            // But, because it may be corrupted, ignore errors.
            try
            {
                ZipEntry de;
                // in lieu of hashset, use a dictionary
                var previouslySeen = new Dictionary <String, Object>();
                while ((de = ZipEntry.ReadDirEntry(zf, previouslySeen)) != null)
                {
                    // Housekeeping: Since ZipFile exposes ZipEntry elements in the enumerator,
                    // we need to copy the comment that we grab from the ZipDirEntry
                    // into the ZipEntry, so the application can access the comment.
                    // Also since ZipEntry is used to Write zip files, we need to copy the
                    // file attributes to the ZipEntry as appropriate.
                    ZipEntry e1 = zf._entries[de.FileName];
                    if (e1 != null)
                    {
                        e1._Comment = de.Comment;
                        if (de.IsDirectory)
                        {
                            e1.MarkAsDirectory();
                        }
                    }
                    previouslySeen.Add(de.FileName, null); // to prevent dupes
                }

                // workitem 8299
                if (zf._locEndOfCDS > 0)
                {
                    zf.ReadStream.Seek(zf._locEndOfCDS, SeekOrigin.Begin);
                }

                ReadCentralDirectoryFooter(zf);

                if (zf.Verbose && !String.IsNullOrEmpty(zf.Comment))
                {
                    zf.StatusMessageTextWriter.WriteLine("Zip file Comment: {0}", zf.Comment);
                }
            }
            catch (ZipException) { }
            catch (IOException) { }

            zf.OnReadCompleted();
        }
        private static void ReadCentralDirectory(ZipFile zf)
        {
            // We must have the central directory footer record, in order to properly
            // read zip dir entries from the central directory.  This because the logic
            // knows when to open a spanned file when the volume number for the central
            // directory differs from the volume number for the zip entry.  The
            // _diskNumberWithCd was set when originally finding the offset for the
            // start of the Central Directory.

            // workitem 9214
            bool     inputUsesZip64 = false;
            ZipEntry de;
            // in lieu of hashset, use a dictionary
            var previouslySeen = new Dictionary <String, object>();

            while ((de = ZipEntry.ReadDirEntry(zf, previouslySeen)) != null)
            {
                de.ResetDirEntry();
                zf.OnReadEntry(true, null);

                if (zf.Verbose)
                {
                    zf.StatusMessageTextWriter.WriteLine("entry {0}", de.FileName);
                }

                zf._entries.Add(de.FileName, de);

                // workitem 9214
                if (de._InputUsesZip64)
                {
                    inputUsesZip64 = true;
                }
                previouslySeen.Add(de.FileName, null); // to prevent dupes
            }

            // workitem 9214; auto-set the zip64 flag
            if (inputUsesZip64)
            {
                zf.UseZip64WhenSaving = Zip64Option.Always;
            }

            // workitem 8299
            if (zf._locEndOfCDS > 0)
            {
                zf.ReadStream.Seek(zf._locEndOfCDS, SeekOrigin.Begin);
            }

            ReadCentralDirectoryFooter(zf);

            if (zf.Verbose && !String.IsNullOrEmpty(zf.Comment))
            {
                zf.StatusMessageTextWriter.WriteLine("Zip file Comment: {0}", zf.Comment);
            }

            // We keep the read stream open after reading.

            if (zf.Verbose)
            {
                zf.StatusMessageTextWriter.WriteLine("read in {0} entries.", zf._entries.Count);
            }

            zf.OnReadCompleted();
        }