BitMiracle.LibTiff.Classic.Tiff.UnlinkDirectory C# (CSharp) Method

        public bool UnlinkDirectory(short number)
        {
            const string module = "UnlinkDirectory";

            if (m_mode == O_RDONLY)
            {
                ErrorExt(this, m_clientdata, module, "Can not unlink directory in read-only file");
                return false;
            }

            // Go to the directory before the one we want
            // to unlink and nab the offset of the link
            // field we'll need to patch.
            uint nextdir = m_header.tiff_diroff;
            long off = sizeof(short) + sizeof(short);
            for (int n = number - 1; n > 0; n--)
            {
                if (nextdir == 0)
                {
                    ErrorExt(this, m_clientdata, module,
                        "Directory {0} does not exist", number);
                    return false;
                }

                if (!advanceDirectory(ref nextdir, out off))
                    return false;
            }

            // Advance to the directory to be unlinked and fetch the offset of the directory
            // that follows.
            long dummyOff;
            if (!advanceDirectory(ref nextdir, out dummyOff))
                return false;

            // Go back and patch the link field of the preceding directory to point to the
            // offset of the directory that follows.
            seekFile(off, SeekOrigin.Begin);
            if ((m_flags & TiffFlags.SWAB) == TiffFlags.SWAB)
                SwabUInt(ref nextdir);

            if (!writeIntOK((int)nextdir))
            {
                ErrorExt(this, m_clientdata, module, "Error writing directory link");
                return false;
            }

            // Leave directory state setup safely. We don't have facilities for doing inserting
            // and removing directories, so it's safest to just invalidate everything. This means
            // that the caller can only append to the directory chain.
            m_currentCodec.Cleanup();
            if ((m_flags & TiffFlags.MYBUFFER) == TiffFlags.MYBUFFER && m_rawdata != null)
            {
                m_rawdata = null;
                m_rawcc = 0;
            }

            m_flags &= ~(TiffFlags.BEENWRITING | TiffFlags.BUFFERSETUP | TiffFlags.POSTENCODE);
            FreeDirectory();
            setupDefaultDirectory();
            m_diroff = 0; // force link on next write
            m_nextdiroff = 0; // next write must be at end
            m_curoff = 0;
            m_row = -1;
            m_curstrip = -1;
            return true;
        }