Adding upstream version 4:24.2.0.upstream/4%24.2.0

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1464 insertions, 0 deletions

diff --git a/sax/source/expatwrap/saxwriter.cxx b/sax/source/expatwrap/saxwriter.cxx
new file mode 100644
index 0000000000..55608101fa
--- /dev/null
+++ b/sax/source/expatwrap/saxwriter.cxx
@@ -0,0 +1,1464 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <string.h>
+
+#include <cassert>
+#include <set>
+#include <stack>
+#include <vector>
+
+#include <com/sun/star/io/IOException.hpp>
+#include <com/sun/star/lang/WrappedTargetRuntimeException.hpp>
+#include <com/sun/star/lang/XServiceInfo.hpp>
+#include <com/sun/star/uno/XComponentContext.hpp>
+#include <com/sun/star/util/XCloneable.hpp>
+#include <com/sun/star/xml/sax/SAXInvalidCharacterException.hpp>
+#include <com/sun/star/xml/sax/XWriter.hpp>
+
+#include <cppuhelper/exc_hlp.hxx>
+#include <cppuhelper/weak.hxx>
+#include <cppuhelper/implbase.hxx>
+#include <cppuhelper/supportsservice.hxx>
+
+#include <osl/diagnose.h>
+#include <rtl/character.hxx>
+#include <sal/log.hxx>
+
+#include <memory>
+
+using namespace ::osl;
+using namespace ::cppu;
+using namespace ::com::sun::star::uno;
+using namespace ::com::sun::star::lang;
+using namespace ::com::sun::star::xml::sax;
+using namespace ::com::sun::star::util;
+using namespace ::com::sun::star::io;
+
+#define LINEFEED 10
+#define SEQUENCESIZE 1024
+#define MAXCOLUMNCOUNT 72
+
+/******
+*
+*
+* Character conversion functions
+*
+*
+*****/
+
+namespace
+{
+enum SaxInvalidCharacterError
+{
+    SAX_NONE,
+    SAX_WARNING,
+    SAX_ERROR
+};
+
+// Stuff for custom entity names
+struct ReplacementPair
+{
+    OUString name;
+    OUString replacement;
+};
+inline bool operator<(const ReplacementPair& lhs, const ReplacementPair& rhs)
+{
+    return lhs.replacement.compareTo(rhs.replacement) < 0;
+}
+
+class SaxWriterHelper
+{
+#ifdef DBG_UTIL
+public:
+    ::std::stack<OUString> m_DebugStartedElements;
+#endif
+
+private:
+    Reference<XOutputStream> m_out;
+    Sequence<sal_Int8> m_Sequence;
+    sal_Int8* mp_Sequence;
+
+    sal_Int32 nLastLineFeedPos; // is negative after writing a sequence
+    sal_uInt32 nCurrentPos;
+    bool m_bStartElementFinished;
+
+    std::vector<ReplacementPair> m_Replacements;
+
+    /// @throws SAXException
+    sal_uInt32 writeSequence();
+
+    // use only if to insert the bytes more space in the sequence is needed and
+    // so the sequence has to write out and reset rPos to 0
+    // writes sequence only on overflow, sequence could be full on the end (rPos == SEQUENCESIZE)
+    /// @throws SAXException
+    void AddBytes(sal_Int8* pTarget, sal_uInt32& rPos, const sal_Int8* pBytes,
+                  sal_uInt32 nBytesCount);
+    /// @throws SAXException
+    bool convertToXML(const sal_Unicode* pStr, sal_Int32 nStrLen, bool bDoNormalization,
+                      bool bNormalizeWhitespace, sal_Int8* pTarget, sal_uInt32& rPos);
+    /// @throws SAXException
+    void FinishStartElement();
+
+    // Search for the correct replacement
+    const ReplacementPair* findXMLReplacement(const sal_Unicode* pStr, sal_Int32 nStrLen);
+
+public:
+    explicit SaxWriterHelper(Reference<XOutputStream> const& m_TempOut)
+        : m_out(m_TempOut)
+        , m_Sequence(SEQUENCESIZE)
+        , mp_Sequence(nullptr)
+        , nLastLineFeedPos(0)
+        , nCurrentPos(0)
+        , m_bStartElementFinished(true)
+    {
+        OSL_ENSURE(SEQUENCESIZE > 50, "Sequence cache size too small");
+        mp_Sequence = m_Sequence.getArray();
+    }
+    ~SaxWriterHelper()
+    {
+        OSL_ENSURE(!nCurrentPos, "cached Sequence not written");
+        OSL_ENSURE(m_bStartElementFinished, "StartElement not completely written");
+    }
+
+    /// @throws SAXException
+    void insertIndentation(sal_uInt32 m_nLevel);
+
+    // returns whether it works correct or invalid characters were in the string
+    // If there are invalid characters in the string it returns sal_False.
+    // Than the calling method has to throw the needed Exception.
+    /// @throws SAXException
+    bool writeString(const OUString& rWriteOutString, bool bDoNormalization,
+                     bool bNormalizeWhitespace);
+
+    sal_uInt32 GetLastColumnCount() const noexcept
+    {
+        return static_cast<sal_uInt32>(nCurrentPos - nLastLineFeedPos);
+    }
+
+    /// @throws SAXException
+    void startDocument();
+
+    // returns whether it works correct or invalid characters were in the strings
+    // If there are invalid characters in one of the strings it returns sal_False.
+    // Than the calling method has to throw the needed Exception.
+    /// @throws SAXException
+    SaxInvalidCharacterError startElement(const OUString& rName,
+                                          const Reference<XAttributeList>& xAttribs);
+    /// @throws SAXException
+    bool FinishEmptyElement();
+
+    // returns whether it works correct or invalid characters were in the string
+    // If there are invalid characters in the string it returns sal_False.
+    // Than the calling method has to throw the needed Exception.
+    /// @throws SAXException
+    bool endElement(const OUString& rName);
+    /// @throws SAXException
+    void endDocument();
+
+    // returns whether it works correct or invalid characters were in the strings
+    // If there are invalid characters in the string it returns sal_False.
+    // Than the calling method has to throw the needed Exception.
+    /// @throws SAXException
+    bool processingInstruction(const OUString& rTarget, const OUString& rData);
+    /// @throws SAXException
+    void startCDATA();
+    /// @throws SAXException
+    void endCDATA();
+
+    // returns whether it works correct or invalid characters were in the strings
+    // If there are invalid characters in the string it returns sal_False.
+    // Than the calling method has to throw the needed Exception.
+    /// @throws SAXException
+    bool comment(const OUString& rComment);
+
+    /// @throws SAXException
+    void clearBuffer();
+
+    // Use custom entity names
+    void setCustomEntityNames(
+        const ::css::uno::Sequence<::css::beans::Pair<::rtl::OUString, ::rtl::OUString>>&
+            replacements);
+
+    // Calculate length for convertToXML
+    sal_Int32 calcXMLByteLength(const OUString& rStr, bool bDoNormalization,
+                                bool bNormalizeWhitespace);
+};
+
+const bool g_bValidCharsBelow32[32] = {
+    // clang-format off
+//  0      1      2      3      4      5      6      7
+    false, false, false, false, false, false, false, false,  //0
+    false, true,  true,  false, false, true,  false, false,  //8
+    false, false, false, false, false, false, false, false,  //16
+    false, false, false, false, false, false, false, false
+    // clang-format on
+};
+
+bool IsInvalidChar(const sal_Unicode aChar)
+{
+    bool bRet(false);
+    // check first for the most common characters
+    if (aChar < 32 || aChar >= 0xd800)
+        bRet = ((aChar < 32 && !g_bValidCharsBelow32[aChar]) || aChar == 0xffff || aChar == 0xfffe);
+    return bRet;
+}
+
+/********
+* write through to the output stream
+*
+*****/
+sal_uInt32 SaxWriterHelper::writeSequence()
+{
+    try
+    {
+        m_out->writeBytes(m_Sequence);
+    }
+    catch (const IOException&)
+    {
+        css::uno::Any anyEx = cppu::getCaughtException();
+        throw SAXException("IO exception during writing", Reference<XInterface>(), anyEx);
+    }
+    nLastLineFeedPos -= SEQUENCESIZE;
+    return 0;
+}
+
+void SaxWriterHelper::AddBytes(sal_Int8* pTarget, sal_uInt32& rPos, const sal_Int8* pBytes,
+                               sal_uInt32 nBytesCount)
+{
+    OSL_ENSURE((rPos + nBytesCount) > SEQUENCESIZE, "wrong use of AddBytesMethod");
+    sal_uInt32 nCount(SEQUENCESIZE - rPos);
+    memcpy(&(pTarget[rPos]), pBytes, nCount);
+
+    OSL_ENSURE(rPos + nCount == SEQUENCESIZE, "the position should be the at the end");
+
+    rPos = writeSequence();
+    sal_uInt32 nRestCount(nBytesCount - nCount);
+    if ((rPos + nRestCount) <= SEQUENCESIZE)
+    {
+        memcpy(&(pTarget[rPos]), &pBytes[nCount], nRestCount);
+        rPos += nRestCount;
+    }
+    else
+        AddBytes(pTarget, rPos, &pBytes[nCount], nRestCount);
+}
+
+void SaxWriterHelper::setCustomEntityNames(
+    const ::css::uno::Sequence<::css::beans::Pair<::rtl::OUString, ::rtl::OUString>>& replacements)
+{
+    m_Replacements.resize(replacements.size());
+    for (size_t i = 0; i < replacements.size(); ++i)
+    {
+        m_Replacements[i].name = replacements[i].First;
+        m_Replacements[i].replacement = replacements[i].Second;
+    }
+    if (replacements.size() > 1)
+        std::sort(m_Replacements.begin(), m_Replacements.end());
+}
+
+/** Converts a UTF-16 string to UTF-8 and does XML normalization
+
+    @param pTarget
+           Pointer to a piece of memory, to where the output should be written. The caller
+           must call calcXMLByteLength on the same string, to ensure,
+           that there is enough memory for converting.
+ */
+bool SaxWriterHelper::convertToXML(const sal_Unicode* pStr, sal_Int32 nStrLen,
+                                   bool bDoNormalization, bool bNormalizeWhitespace,
+                                   sal_Int8* pTarget, sal_uInt32& rPos)
+{
+    bool bRet(true);
+    sal_uInt32 nSurrogate = 0;
+
+    for (sal_Int32 i = 0; i < nStrLen; i++)
+    {
+        sal_Unicode c = pStr[i];
+        if (IsInvalidChar(c))
+            bRet = false;
+        else if ((c >= 0x0001) && (c <= 0x007F)) // Deal with ascii
+        {
+            if (bDoNormalization)
+            {
+                switch (c)
+                {
+                    case '&': // resemble to &amp;
+                    {
+                        if ((rPos + 5) > SEQUENCESIZE)
+                            AddBytes(pTarget, rPos, reinterpret_cast<sal_Int8 const*>("&amp;"), 5);
+                        else
+                        {
+                            memcpy(&(pTarget[rPos]), "&amp;", 5);
+                            rPos += 5;
+                        }
+                    }
+                    break;
+                    case '<':
+                    {
+                        if ((rPos + 4) > SEQUENCESIZE)
+                            AddBytes(pTarget, rPos, reinterpret_cast<sal_Int8 const*>("&lt;"), 4);
+                        else
+                        {
+                            memcpy(&(pTarget[rPos]), "&lt;", 4);
+                            rPos += 4; // &lt;
+                        }
+                    }
+                    break;
+                    case '>':
+                    {
+                        if ((rPos + 4) > SEQUENCESIZE)
+                            AddBytes(pTarget, rPos, reinterpret_cast<sal_Int8 const*>("&gt;"), 4);
+                        else
+                        {
+                            memcpy(&(pTarget[rPos]), "&gt;", 4);
+                            rPos += 4; // &gt;
+                        }
+                    }
+                    break;
+                    case '\'':
+                    {
+                        if ((rPos + 6) > SEQUENCESIZE)
+                            AddBytes(pTarget, rPos, reinterpret_cast<sal_Int8 const*>("&apos;"), 6);
+                        else
+                        {
+                            memcpy(&(pTarget[rPos]), "&apos;", 6);
+                            rPos += 6; // &apos;
+                        }
+                    }
+                    break;
+                    case '"':
+                    {
+                        if ((rPos + 6) > SEQUENCESIZE)
+                            AddBytes(pTarget, rPos, reinterpret_cast<sal_Int8 const*>("&quot;"), 6);
+                        else
+                        {
+                            memcpy(&(pTarget[rPos]), "&quot;", 6);
+                            rPos += 6; // &quot;
+                        }
+                    }
+                    break;
+                    case 13:
+                    {
+                        if ((rPos + 6) > SEQUENCESIZE)
+                            AddBytes(pTarget, rPos, reinterpret_cast<sal_Int8 const*>("&#x0d;"), 6);
+                        else
+                        {
+                            memcpy(&(pTarget[rPos]), "&#x0d;", 6);
+                            rPos += 6;
+                        }
+                    }
+                    break;
+                    case LINEFEED:
+                    {
+                        if (bNormalizeWhitespace)
+                        {
+                            if ((rPos + 6) > SEQUENCESIZE)
+                                AddBytes(pTarget, rPos, reinterpret_cast<sal_Int8 const*>("&#x0a;"),
+                                         6);
+                            else
+                            {
+                                memcpy(&(pTarget[rPos]), "&#x0a;", 6);
+                                rPos += 6;
+                            }
+                        }
+                        else
+                        {
+                            pTarget[rPos] = LINEFEED;
+                            nLastLineFeedPos = rPos;
+                            rPos++;
+                        }
+                    }
+                    break;
+                    case 9:
+                    {
+                        if (bNormalizeWhitespace)
+                        {
+                            if ((rPos + 6) > SEQUENCESIZE)
+                                AddBytes(pTarget, rPos, reinterpret_cast<sal_Int8 const*>("&#x09;"),
+                                         6);
+                            else
+                            {
+                                memcpy(&(pTarget[rPos]), "&#x09;", 6);
+                                rPos += 6;
+                            }
+                        }
+                        else
+                        {
+                            pTarget[rPos] = 9;
+                            rPos++;
+                        }
+                    }
+                    break;
+                    default:
+                    {
+                        pTarget[rPos] = static_cast<sal_Int8>(c);
+                        rPos++;
+                    }
+                    break;
+                }
+            }
+            else
+            {
+                pTarget[rPos] = static_cast<sal_Int8>(c);
+                if (static_cast<sal_Int8>(c) == LINEFEED)
+                    nLastLineFeedPos = rPos;
+                rPos++;
+            }
+        }
+        else
+        {
+            // Deal with replacements
+            if (bDoNormalization && !m_Replacements.empty())
+            {
+                // search
+                const ReplacementPair* it = findXMLReplacement(&pStr[i], nStrLen - i);
+
+                // replace
+                if (it != nullptr)
+                {
+                    OString name = ::rtl::OUStringToOString(it->name, RTL_TEXTENCODING_UTF8);
+                    if (rPos + name.getLength() > SEQUENCESIZE)
+                        AddBytes(pTarget, rPos, reinterpret_cast<sal_Int8 const*>(name.getStr()),
+                                 name.getLength());
+                    else
+                    {
+                        memcpy(&(pTarget[rPos]), name.getStr(), name.getLength());
+                        rPos += name.getLength();
+                    }
+                    i += it->replacement.getLength() - 1;
+                    continue;
+                }
+            }
+
+            // Deal with other unicode cases
+            if (rtl::isHighSurrogate(c))
+            {
+                // 1. surrogate: save (until 2. surrogate)
+                if (nSurrogate != 0) // left-over lone 1st Unicode surrogate
+                {
+                    OSL_FAIL("left-over Unicode surrogate");
+                    bRet = false;
+                }
+                nSurrogate = c;
+            }
+            else if (rtl::isLowSurrogate(c))
+            {
+                // 2. surrogate: write as UTF-8
+                if (nSurrogate) // can only be 1st surrogate
+                {
+                    nSurrogate = rtl::combineSurrogates(nSurrogate, c);
+                    sal_Int8 aBytes[] = { sal_Int8(0xF0 | ((nSurrogate >> 18) & 0x0F)),
+                                          sal_Int8(0x80 | ((nSurrogate >> 12) & 0x3F)),
+                                          sal_Int8(0x80 | ((nSurrogate >> 6) & 0x3F)),
+                                          sal_Int8(0x80 | ((nSurrogate >> 0) & 0x3F)) };
+                    if ((rPos + 4) > SEQUENCESIZE)
+                        AddBytes(pTarget, rPos, aBytes, 4);
+                    else
+                    {
+                        pTarget[rPos] = aBytes[0];
+                        rPos++;
+                        pTarget[rPos] = aBytes[1];
+                        rPos++;
+                        pTarget[rPos] = aBytes[2];
+                        rPos++;
+                        pTarget[rPos] = aBytes[3];
+                        rPos++;
+                    }
+                }
+                else // lone 2nd surrogate
+                {
+                    OSL_FAIL("illegal Unicode character");
+                    bRet = false;
+                }
+
+                // reset surrogate
+                nSurrogate = 0;
+            }
+            else if (c > 0x07FF)
+            {
+                sal_Int8 aBytes[]
+                    = { sal_Int8(0xE0 | ((c >> 12) & 0x0F)), sal_Int8(0x80 | ((c >> 6) & 0x3F)),
+                        sal_Int8(0x80 | ((c >> 0) & 0x3F)) };
+                if ((rPos + 3) > SEQUENCESIZE)
+                    AddBytes(pTarget, rPos, aBytes, 3);
+                else
+                {
+                    pTarget[rPos] = aBytes[0];
+                    rPos++;
+                    pTarget[rPos] = aBytes[1];
+                    rPos++;
+                    pTarget[rPos] = aBytes[2];
+                    rPos++;
+                }
+            }
+            else
+            {
+                sal_Int8 aBytes[]
+                    = { sal_Int8(0xC0 | ((c >> 6) & 0x1F)), sal_Int8(0x80 | ((c >> 0) & 0x3F)) };
+                if ((rPos + 2) > SEQUENCESIZE)
+                    AddBytes(pTarget, rPos, aBytes, 2);
+                else
+                {
+                    pTarget[rPos] = aBytes[0];
+                    rPos++;
+                    pTarget[rPos] = aBytes[1];
+                    rPos++;
+                }
+            }
+        }
+
+        OSL_ENSURE(rPos <= SEQUENCESIZE, "not reset current position");
+        if (rPos == SEQUENCESIZE)
+            rPos = writeSequence();
+
+        // reset left-over surrogate
+        if ((nSurrogate != 0) && !rtl::isHighSurrogate(c))
+        {
+            OSL_FAIL("left-over Unicode surrogate");
+            nSurrogate = 0;
+            bRet = false;
+        }
+    }
+    if (nSurrogate != 0) // trailing lone 1st surrogate
+    {
+        OSL_FAIL("left-over Unicode surrogate");
+        bRet = false;
+    }
+    return bRet;
+}
+
+void SaxWriterHelper::FinishStartElement()
+{
+    if (!m_bStartElementFinished)
+    {
+        mp_Sequence[nCurrentPos] = '>';
+        nCurrentPos++;
+        if (nCurrentPos == SEQUENCESIZE)
+            nCurrentPos = writeSequence();
+        m_bStartElementFinished = true;
+    }
+}
+
+void SaxWriterHelper::insertIndentation(sal_uInt32 m_nLevel)
+{
+    FinishStartElement();
+    if (m_nLevel > 0)
+    {
+        if ((nCurrentPos + m_nLevel + 1) <= SEQUENCESIZE)
+        {
+            mp_Sequence[nCurrentPos] = LINEFEED;
+            nLastLineFeedPos = nCurrentPos;
+            nCurrentPos++;
+            memset(&(mp_Sequence[nCurrentPos]), 32, m_nLevel);
+            nCurrentPos += m_nLevel;
+            if (nCurrentPos == SEQUENCESIZE)
+                nCurrentPos = writeSequence();
+        }
+        else
+        {
+            sal_uInt32 nCount(m_nLevel + 1);
+            std::unique_ptr<sal_Int8[]> pBytes(new sal_Int8[nCount]);
+            pBytes[0] = LINEFEED;
+            memset(&(pBytes[1]), 32, m_nLevel);
+            AddBytes(mp_Sequence, nCurrentPos, pBytes.get(), nCount);
+            pBytes.reset();
+            nLastLineFeedPos = nCurrentPos - nCount;
+            if (nCurrentPos == SEQUENCESIZE)
+                nCurrentPos = writeSequence();
+        }
+    }
+    else
+    {
+        mp_Sequence[nCurrentPos] = LINEFEED;
+        nLastLineFeedPos = nCurrentPos;
+        nCurrentPos++;
+        if (nCurrentPos == SEQUENCESIZE)
+            nCurrentPos = writeSequence();
+    }
+}
+
+bool SaxWriterHelper::writeString(const OUString& rWriteOutString, bool bDoNormalization,
+                                  bool bNormalizeWhitespace)
+{
+    FinishStartElement();
+    return convertToXML(rWriteOutString.getStr(), rWriteOutString.getLength(), bDoNormalization,
+                        bNormalizeWhitespace, mp_Sequence, nCurrentPos);
+}
+
+void SaxWriterHelper::startDocument()
+{
+    const char pc[] = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>";
+    const int nLen = strlen(pc);
+    if ((nCurrentPos + nLen) <= SEQUENCESIZE)
+    {
+        memcpy(mp_Sequence, pc, nLen);
+        nCurrentPos += nLen;
+    }
+    else
+    {
+        AddBytes(mp_Sequence, nCurrentPos, reinterpret_cast<sal_Int8 const*>(pc), nLen);
+    }
+    OSL_ENSURE(nCurrentPos <= SEQUENCESIZE, "not reset current position");
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+    mp_Sequence[nCurrentPos] = LINEFEED;
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+}
+
+#ifndef NDEBUG
+bool inrange(sal_Unicode c, sal_Unicode start, sal_Unicode end) { return c >= start && c <= end; }
+#endif
+
+void CheckValidName(OUString const& rName)
+{
+#ifdef NDEBUG
+    (void)rName;
+#else
+    assert(!rName.isEmpty());
+    bool hasColon(false);
+    for (sal_Int32 i = 0; i < rName.getLength(); ++i)
+    {
+        auto const c(rName[i]);
+        if (c == ':')
+        {
+            // see https://www.w3.org/TR/REC-xml-names/#ns-qualnames
+            SAL_WARN_IF(hasColon, "sax", "only one colon allowed: " << rName);
+            assert(!hasColon && "only one colon allowed");
+            hasColon = true;
+        }
+        else if (!rtl::isAsciiAlphanumeric(c) && c != '_' && c != '-' && c != '.'
+                 && !inrange(c, 0x00C0, 0x00D6) && !inrange(c, 0x00D8, 0x00F6)
+                 && !inrange(c, 0x00F8, 0x02FF) && !inrange(c, 0x0370, 0x037D)
+                 && !inrange(c, 0x037F, 0x1FFF) && !inrange(c, 0x200C, 0x200D)
+                 && !inrange(c, 0x2070, 0x218F) && !inrange(c, 0x2C00, 0x2FEF)
+                 && !inrange(c, 0x3001, 0xD7FF) && !inrange(c, 0xF900, 0xFDCF)
+                 && !inrange(c, 0xFDF0, 0xFFFD) && c != 0x00B7 && !inrange(c, 0x0300, 0x036F)
+                 && !inrange(c, 0x203F, 0x2040))
+        {
+            // https://www.w3.org/TR/xml11/#NT-NameChar
+            // (currently we don't warn about invalid start chars)
+            SAL_WARN("sax", "unexpected character in attribute name: " << rName);
+            assert(!"unexpected character in attribute name");
+        }
+    }
+#endif
+}
+
+SaxInvalidCharacterError SaxWriterHelper::startElement(const OUString& rName,
+                                                       const Reference<XAttributeList>& xAttribs)
+{
+    FinishStartElement();
+
+#ifdef DBG_UTIL
+    m_DebugStartedElements.push(rName);
+    ::std::set<OUString> DebugAttributes;
+#endif
+
+    mp_Sequence[nCurrentPos] = '<';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+
+    SaxInvalidCharacterError eRet(SAX_NONE);
+    CheckValidName(rName);
+    if (!writeString(rName, false, false))
+        eRet = SAX_ERROR;
+
+    sal_Int16 nAttribCount = xAttribs.is() ? xAttribs->getLength() : 0;
+    for (sal_Int16 i = 0; i < nAttribCount; i++)
+    {
+        mp_Sequence[nCurrentPos] = ' ';
+        nCurrentPos++;
+        if (nCurrentPos == SEQUENCESIZE)
+            nCurrentPos = writeSequence();
+
+        OUString const& rAttrName(xAttribs->getNameByIndex(i));
+#ifdef DBG_UTIL
+        // Well-formedness constraint: Unique Att Spec
+        assert(DebugAttributes.find(rAttrName) == DebugAttributes.end());
+        DebugAttributes.insert(rAttrName);
+#endif
+        CheckValidName(rAttrName);
+        if (!writeString(rAttrName, false, false))
+            eRet = SAX_ERROR;
+
+        mp_Sequence[nCurrentPos] = '=';
+        nCurrentPos++;
+        if (nCurrentPos == SEQUENCESIZE)
+            nCurrentPos = writeSequence();
+        mp_Sequence[nCurrentPos] = '"';
+        nCurrentPos++;
+        if (nCurrentPos == SEQUENCESIZE)
+            nCurrentPos = writeSequence();
+
+        if (!writeString(xAttribs->getValueByIndex(i), true, true) && eRet != SAX_ERROR)
+            eRet = SAX_WARNING;
+
+        mp_Sequence[nCurrentPos] = '"';
+        nCurrentPos++;
+        if (nCurrentPos == SEQUENCESIZE)
+            nCurrentPos = writeSequence();
+    }
+
+    m_bStartElementFinished = false; // because the '>' character is not added,
+        // because it is possible, that the "/>"
+        // characters have to add
+    return eRet;
+}
+
+bool SaxWriterHelper::FinishEmptyElement()
+{
+    if (m_bStartElementFinished)
+        return false;
+
+    mp_Sequence[nCurrentPos] = '/';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+    mp_Sequence[nCurrentPos] = '>';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+
+    m_bStartElementFinished = true;
+
+    return true;
+}
+
+bool SaxWriterHelper::endElement(const OUString& rName)
+{
+    FinishStartElement();
+
+    mp_Sequence[nCurrentPos] = '<';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+    mp_Sequence[nCurrentPos] = '/';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+
+    CheckValidName(rName);
+    bool bRet(writeString(rName, false, false));
+
+    mp_Sequence[nCurrentPos] = '>';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+
+    return bRet;
+}
+
+void SaxWriterHelper::endDocument()
+{
+    if (nCurrentPos > 0)
+    {
+        m_Sequence.realloc(nCurrentPos);
+        nCurrentPos = writeSequence();
+        //m_Sequence.realloc(SEQUENCESIZE);
+    }
+}
+
+void SaxWriterHelper::clearBuffer()
+{
+    FinishStartElement();
+    if (nCurrentPos > 0)
+    {
+        m_Sequence.realloc(nCurrentPos);
+        nCurrentPos = writeSequence();
+        m_Sequence.realloc(SEQUENCESIZE);
+        // Be sure to update the array pointer after the reallocation.
+        mp_Sequence = m_Sequence.getArray();
+    }
+}
+
+bool SaxWriterHelper::processingInstruction(const OUString& rTarget, const OUString& rData)
+{
+    FinishStartElement();
+    mp_Sequence[nCurrentPos] = '<';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+    mp_Sequence[nCurrentPos] = '?';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+
+    bool bRet(writeString(rTarget, false, false));
+
+    mp_Sequence[nCurrentPos] = ' ';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+
+    if (!writeString(rData, false, false))
+        bRet = false;
+
+    mp_Sequence[nCurrentPos] = '?';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+    mp_Sequence[nCurrentPos] = '>';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+
+    return bRet;
+}
+
+void SaxWriterHelper::startCDATA()
+{
+    FinishStartElement();
+    if ((nCurrentPos + 9) <= SEQUENCESIZE)
+    {
+        memcpy(&(mp_Sequence[nCurrentPos]), "<![CDATA[", 9);
+        nCurrentPos += 9;
+    }
+    else
+        AddBytes(mp_Sequence, nCurrentPos, reinterpret_cast<sal_Int8 const*>("<![CDATA["), 9);
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+}
+
+void SaxWriterHelper::endCDATA()
+{
+    FinishStartElement();
+    if ((nCurrentPos + 3) <= SEQUENCESIZE)
+    {
+        memcpy(&(mp_Sequence[nCurrentPos]), "]]>", 3);
+        nCurrentPos += 3;
+    }
+    else
+        AddBytes(mp_Sequence, nCurrentPos, reinterpret_cast<sal_Int8 const*>("]]>"), 3);
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+}
+
+bool SaxWriterHelper::comment(const OUString& rComment)
+{
+    FinishStartElement();
+    mp_Sequence[nCurrentPos] = '<';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+    mp_Sequence[nCurrentPos] = '!';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+    mp_Sequence[nCurrentPos] = '-';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+    mp_Sequence[nCurrentPos] = '-';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+
+    bool bRet(writeString(rComment, false, false));
+
+    mp_Sequence[nCurrentPos] = '-';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+    mp_Sequence[nCurrentPos] = '-';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+    mp_Sequence[nCurrentPos] = '>';
+    nCurrentPos++;
+    if (nCurrentPos == SEQUENCESIZE)
+        nCurrentPos = writeSequence();
+
+    return bRet;
+}
+
+sal_Int32 SaxWriterHelper::calcXMLByteLength(const OUString& rStr, bool bDoNormalization,
+                                             bool bNormalizeWhitespace)
+{
+    sal_Int32 nOutputLength = 0;
+    sal_uInt32 nSurrogate = 0;
+
+    const sal_Unicode* pStr = rStr.getStr();
+    sal_Int32 nStrLen = rStr.getLength();
+    for (sal_Int32 i = 0; i < nStrLen; i++)
+    {
+        sal_uInt16 c = pStr[i];
+        if (!IsInvalidChar(c) && (c >= 0x0001) && (c <= 0x007F))
+        {
+            if (bDoNormalization)
+            {
+                switch (c)
+                {
+                    case '&': // resemble to &amp;
+                        nOutputLength += 5;
+                        break;
+                    case '<': // &lt;
+                    case '>': // &gt;
+                        nOutputLength += 4;
+                        break;
+                    case '\'': // &apos;
+                    case '"': // &quot;
+                    case 13: // &#x0d;
+                        nOutputLength += 6;
+                        break;
+
+                    case 10: // &#x0a;
+                    case 9: // &#x09;
+                        if (bNormalizeWhitespace)
+                        {
+                            nOutputLength += 6;
+                        }
+                        else
+                        {
+                            nOutputLength++;
+                        }
+                        break;
+                    default:
+                        nOutputLength++;
+                }
+            }
+            else
+            {
+                nOutputLength++;
+            }
+        }
+        else
+        {
+            // Deal with replacements
+            if (bDoNormalization && !m_Replacements.empty())
+            {
+                // search
+                const ReplacementPair* it = findXMLReplacement(&pStr[i], nStrLen - i);
+
+                if (it != nullptr)
+                {
+                    nOutputLength
+                        += ::rtl::OUStringToOString(it->name, RTL_TEXTENCODING_UTF8).getLength();
+                    i += it->replacement.getLength() - 1;
+                    continue;
+                }
+            }
+
+            // Deal with other unicode cases
+            if (rtl::isHighSurrogate(c))
+            {
+                // save surrogate
+                nSurrogate = c;
+            }
+            else if (rtl::isLowSurrogate(c))
+            {
+                // 2. surrogate: write as UTF-8 (if range is OK
+                if (nSurrogate)
+                    nOutputLength += 4;
+                nSurrogate = 0;
+            }
+            else if (c > 0x07FF)
+            {
+                nOutputLength += 3;
+            }
+            else
+            {
+                nOutputLength += 2;
+            }
+        }
+
+        // surrogate processing
+        if ((nSurrogate != 0) && !rtl::isHighSurrogate(c))
+            nSurrogate = 0;
+    }
+
+    return nOutputLength;
+}
+
+const ReplacementPair* SaxWriterHelper::findXMLReplacement(const sal_Unicode* pStr,
+                                                           sal_Int32 nStrLen)
+{
+    for (size_t iter = 0; iter < m_Replacements.size(); ++iter)
+    {
+        if (m_Replacements[iter].replacement.getLength() > nStrLen)
+            continue;
+        sal_Int32 matches = m_Replacements[iter].replacement.compareTo(
+            std::u16string_view(pStr, m_Replacements[iter].replacement.getLength()));
+        if (matches == 0)
+            return &m_Replacements[iter];
+        if (matches > 0)
+            return nullptr;
+    }
+    return nullptr;
+}
+
+class SAXWriter : public WeakImplHelper<XWriter, XServiceInfo>
+{
+public:
+    SAXWriter()
+        : m_bDocStarted(false)
+        , m_bIsCDATA(false)
+        , m_bForceLineBreak(false)
+        , m_bAllowLineBreak(false)
+        , m_nLevel(0)
+    {
+    }
+
+public: // XActiveDataSource
+    virtual void SAL_CALL setOutputStream(const Reference<XOutputStream>& aStream) override
+    {
+        try
+        {
+            // temporary: set same stream again to clear buffer
+            if (m_out == aStream && m_pSaxWriterHelper && m_bDocStarted)
+                m_pSaxWriterHelper->clearBuffer();
+            else
+            {
+                m_out = aStream;
+                m_pSaxWriterHelper.reset(new SaxWriterHelper(m_out));
+                m_bDocStarted = false;
+                m_nLevel = 0;
+                m_bIsCDATA = false;
+            }
+        }
+        catch (const SAXException& e)
+        {
+            throw css::lang::WrappedTargetRuntimeException(e.Message, getXWeak(),
+                                                           e.WrappedException);
+        }
+    }
+    virtual Reference<XOutputStream> SAL_CALL getOutputStream() override { return m_out; }
+
+public: // XDocumentHandler
+    virtual void SAL_CALL startDocument() override;
+
+    virtual void SAL_CALL endDocument() override;
+
+    virtual void SAL_CALL startElement(const OUString& aName,
+                                       const Reference<XAttributeList>& xAttribs) override;
+
+    virtual void SAL_CALL endElement(const OUString& aName) override;
+
+    virtual void SAL_CALL characters(const OUString& aChars) override;
+
+    virtual void SAL_CALL ignorableWhitespace(const OUString& aWhitespaces) override;
+    virtual void SAL_CALL processingInstruction(const OUString& aTarget,
+                                                const OUString& aData) override;
+    virtual void SAL_CALL setDocumentLocator(const Reference<XLocator>& xLocator) override;
+    virtual void SAL_CALL setCustomEntityNames(
+        const ::css::uno::Sequence<::css::beans::Pair<::rtl::OUString, ::rtl::OUString>>&
+            replacements) override;
+
+public: // XExtendedDocumentHandler
+    virtual void SAL_CALL startCDATA() override;
+    virtual void SAL_CALL endCDATA() override;
+    virtual void SAL_CALL comment(const OUString& sComment) override;
+    virtual void SAL_CALL unknown(const OUString& sString) override;
+    virtual void SAL_CALL allowLineBreak() override;
+
+public: // XServiceInfo
+    OUString SAL_CALL getImplementationName() override;
+    Sequence<OUString> SAL_CALL getSupportedServiceNames() override;
+    sal_Bool SAL_CALL supportsService(const OUString& ServiceName) override;
+
+private:
+    sal_Int32 getIndentPrefixLength(sal_Int32 nFirstLineBreakOccurrence) noexcept;
+
+    Reference<XOutputStream> m_out;
+    std::unique_ptr<SaxWriterHelper> m_pSaxWriterHelper;
+
+    // Status information
+    bool m_bDocStarted : 1;
+    bool m_bIsCDATA : 1;
+    bool m_bForceLineBreak : 1;
+    bool m_bAllowLineBreak : 1;
+    sal_Int32 m_nLevel;
+};
+
+sal_Int32 SAXWriter::getIndentPrefixLength(sal_Int32 nFirstLineBreakOccurrence) noexcept
+{
+    sal_Int32 nLength = -1;
+    if (m_pSaxWriterHelper)
+    {
+        if (m_bForceLineBreak
+            || (m_bAllowLineBreak
+                && ((nFirstLineBreakOccurrence + m_pSaxWriterHelper->GetLastColumnCount())
+                    > MAXCOLUMNCOUNT)))
+            nLength = m_nLevel;
+    }
+    m_bForceLineBreak = false;
+    m_bAllowLineBreak = false;
+    return nLength;
+}
+
+bool isFirstCharWhitespace(const sal_Unicode* p) noexcept { return *p == ' '; }
+
+// XServiceInfo
+OUString SAXWriter::getImplementationName() { return "com.sun.star.extensions.xml.sax.Writer"; }
+
+// XServiceInfo
+sal_Bool SAXWriter::supportsService(const OUString& ServiceName)
+{
+    return cppu::supportsService(this, ServiceName);
+}
+
+// XServiceInfo
+Sequence<OUString> SAXWriter::getSupportedServiceNames()
+{
+    return { "com.sun.star.xml.sax.Writer" };
+}
+
+void SAXWriter::startDocument()
+{
+    if (m_bDocStarted || !m_out.is() || !m_pSaxWriterHelper)
+    {
+        throw SAXException();
+    }
+    m_bDocStarted = true;
+    m_pSaxWriterHelper->startDocument();
+}
+
+void SAXWriter::endDocument()
+{
+    if (!m_bDocStarted)
+    {
+        throw SAXException("endDocument called before startDocument", Reference<XInterface>(),
+                           Any());
+    }
+    if (m_nLevel)
+    {
+        throw SAXException("unexpected end of document", Reference<XInterface>(), Any());
+    }
+    m_pSaxWriterHelper->endDocument();
+    try
+    {
+        m_out->closeOutput();
+    }
+    catch (const IOException&)
+    {
+        css::uno::Any anyEx = cppu::getCaughtException();
+        throw SAXException("IO exception during closing the IO Stream", Reference<XInterface>(),
+                           anyEx);
+    }
+}
+
+void SAXWriter::startElement(const OUString& aName, const Reference<XAttributeList>& xAttribs)
+{
+    if (!m_bDocStarted)
+    {
+        throw SAXException("startElement called before startDocument", {}, {});
+    }
+    if (m_bIsCDATA)
+    {
+        throw SAXException("startElement call not allowed with CDATA sections", {}, {});
+    }
+
+    sal_Int32 nLength(0);
+    if (m_bAllowLineBreak)
+    {
+        sal_Int32 nAttribCount = xAttribs.is() ? xAttribs->getLength() : 0;
+
+        nLength++; // "<"
+        nLength += m_pSaxWriterHelper->calcXMLByteLength(aName, false, false); // the tag name
+
+        sal_Int16 n;
+        for (n = 0; n < static_cast<sal_Int16>(nAttribCount); n++)
+        {
+            nLength++; // " "
+            OUString tmp = xAttribs->getNameByIndex(n);
+
+            nLength += m_pSaxWriterHelper->calcXMLByteLength(tmp, false, false);
+
+            nLength += 2; // ="
+
+            tmp = xAttribs->getValueByIndex(n);
+
+            nLength += m_pSaxWriterHelper->calcXMLByteLength(tmp, true, true);
+
+            nLength += 1; // "
+        }
+
+        nLength++; // '>'
+    }
+
+    // Is there a new indentation necessary ?
+    sal_Int32 nPrefix(getIndentPrefixLength(nLength));
+
+    // write into sequence
+    if (nPrefix >= 0)
+        m_pSaxWriterHelper->insertIndentation(nPrefix);
+
+    SaxInvalidCharacterError eRet(m_pSaxWriterHelper->startElement(aName, xAttribs));
+
+    m_nLevel++;
+
+    if (eRet == SAX_WARNING)
+    {
+        throw SAXInvalidCharacterException(
+            "Invalid character during XML-Export in an attribute value", {}, {});
+    }
+    else if (eRet == SAX_ERROR)
+    {
+        throw SAXException("Invalid character during XML-Export", {}, {});
+    }
+}
+
+void SAXWriter::endElement(const OUString& aName)
+{
+    if (!m_bDocStarted)
+    {
+        throw SAXException();
+    }
+    m_nLevel--;
+
+    if (m_nLevel < 0)
+    {
+        throw SAXException();
+    }
+    bool bRet(true);
+
+    // check here because Helper's endElement is not always called
+#ifdef DBG_UTIL
+    assert(!m_pSaxWriterHelper->m_DebugStartedElements.empty());
+    // Well-formedness constraint: Element Type Match
+    assert(aName == m_pSaxWriterHelper->m_DebugStartedElements.top());
+    m_pSaxWriterHelper->m_DebugStartedElements.pop();
+#endif
+
+    if (m_pSaxWriterHelper->FinishEmptyElement())
+        m_bForceLineBreak = false;
+    else
+    {
+        // only ascii chars allowed
+        sal_Int32 nLength(0);
+        if (m_bAllowLineBreak)
+            nLength = 3 + m_pSaxWriterHelper->calcXMLByteLength(aName, false, false);
+        sal_Int32 nPrefix = getIndentPrefixLength(nLength);
+
+        if (nPrefix >= 0)
+            m_pSaxWriterHelper->insertIndentation(nPrefix);
+
+        bRet = m_pSaxWriterHelper->endElement(aName);
+    }
+
+    if (!bRet)
+    {
+        throw SAXException("Invalid character during XML-Export", {}, {});
+    }
+}
+
+void SAXWriter::characters(const OUString& aChars)
+{
+    if (!m_bDocStarted)
+    {
+        throw SAXException("characters method called before startDocument", {}, {});
+    }
+
+    bool bThrowException(false);
+    if (!aChars.isEmpty())
+    {
+        if (m_bIsCDATA)
+            bThrowException = !m_pSaxWriterHelper->writeString(aChars, false, false);
+        else
+        {
+            // Note : nFirstLineBreakOccurrence is not exact, because we don't know, how
+            //        many 2 and 3 byte chars are inbetween. However this whole stuff
+            //        is eitherway for pretty printing only, so it does not need to be exact.
+            sal_Int32 nLength(0);
+            sal_Int32 nIndentPrefix(-1);
+            if (m_bAllowLineBreak)
+            {
+                // returns position of first ascii 10 within the string, -1 when no 10 in string.
+                sal_Int32 nFirstLineBreakOccurrence = aChars.indexOf(LINEFEED);
+
+                nLength = m_pSaxWriterHelper->calcXMLByteLength(aChars, !m_bIsCDATA, false);
+                nIndentPrefix = getIndentPrefixLength(
+                    nFirstLineBreakOccurrence >= 0 ? nFirstLineBreakOccurrence : nLength);
+            }
+            else
+                nIndentPrefix = getIndentPrefixLength(nLength);
+
+            // insert indentation
+            if (nIndentPrefix >= 0)
+            {
+                if (isFirstCharWhitespace(aChars.getStr()))
+                    m_pSaxWriterHelper->insertIndentation(nIndentPrefix - 1);
+                else
+                    m_pSaxWriterHelper->insertIndentation(nIndentPrefix);
+            }
+            bThrowException = !m_pSaxWriterHelper->writeString(aChars, true, false);
+        }
+    }
+    if (bThrowException)
+    {
+        throw SAXInvalidCharacterException("Invalid character during XML-Export", {}, {});
+    }
+}
+
+void SAXWriter::ignorableWhitespace(const OUString&)
+{
+    if (!m_bDocStarted)
+    {
+        throw SAXException();
+    }
+
+    m_bForceLineBreak = true;
+}
+
+void SAXWriter::processingInstruction(const OUString& aTarget, const OUString& aData)
+{
+    if (!m_bDocStarted || m_bIsCDATA)
+    {
+        throw SAXException();
+    }
+
+    sal_Int32 nLength(0);
+    if (m_bAllowLineBreak)
+    {
+        nLength = 2; // "<?"
+        nLength += m_pSaxWriterHelper->calcXMLByteLength(aTarget, false, false);
+
+        nLength += 1; // " "
+
+        nLength += m_pSaxWriterHelper->calcXMLByteLength(aData, false, false);
+
+        nLength += 2; // "?>"
+    }
+
+    sal_Int32 nPrefix = getIndentPrefixLength(nLength);
+
+    if (nPrefix >= 0)
+        m_pSaxWriterHelper->insertIndentation(nPrefix);
+
+    if (!m_pSaxWriterHelper->processingInstruction(aTarget, aData))
+    {
+        throw SAXException("Invalid character during XML-Export", {}, {});
+    }
+}
+
+void SAXWriter::setDocumentLocator(const Reference<XLocator>&) {}
+
+void SAXWriter::setCustomEntityNames(
+    const ::css::uno::Sequence<::css::beans::Pair<::rtl::OUString, ::rtl::OUString>>& replacements)
+{
+    m_pSaxWriterHelper->setCustomEntityNames(replacements);
+}
+
+void SAXWriter::startCDATA()
+{
+    if (!m_bDocStarted || m_bIsCDATA)
+    {
+        throw SAXException();
+    }
+
+    sal_Int32 nPrefix = getIndentPrefixLength(9);
+    if (nPrefix >= 0)
+        m_pSaxWriterHelper->insertIndentation(nPrefix);
+
+    m_pSaxWriterHelper->startCDATA();
+
+    m_bIsCDATA = true;
+}
+
+void SAXWriter::endCDATA()
+{
+    if (!m_bDocStarted || !m_bIsCDATA)
+    {
+        throw SAXException("endCDATA was called without startCDATA", {}, {});
+    }
+
+    sal_Int32 nPrefix = getIndentPrefixLength(3);
+    if (nPrefix >= 0)
+        m_pSaxWriterHelper->insertIndentation(nPrefix);
+
+    m_pSaxWriterHelper->endCDATA();
+
+    m_bIsCDATA = false;
+}
+
+void SAXWriter::comment(const OUString& sComment)
+{
+    if (!m_bDocStarted || m_bIsCDATA)
+    {
+        throw SAXException();
+    }
+
+    sal_Int32 nLength(0);
+    if (m_bAllowLineBreak)
+    {
+        nLength = 4; // "<!--"
+        nLength += m_pSaxWriterHelper->calcXMLByteLength(sComment, false, false);
+
+        nLength += 3;
+    }
+
+    sal_Int32 nPrefix = getIndentPrefixLength(nLength);
+    if (nPrefix >= 0)
+        m_pSaxWriterHelper->insertIndentation(nPrefix);
+
+    if (!m_pSaxWriterHelper->comment(sComment))
+    {
+        throw SAXException("Invalid character during XML-Export", {}, {});
+    }
+}
+
+void SAXWriter::allowLineBreak()
+{
+    if (!m_bDocStarted || m_bAllowLineBreak)
+    {
+        throw SAXException();
+    }
+
+    m_bAllowLineBreak = true;
+}
+
+void SAXWriter::unknown(const OUString& sString)
+{
+    if (!m_bDocStarted)
+    {
+        throw SAXException();
+    }
+    if (m_bIsCDATA)
+    {
+        throw SAXException();
+    }
+
+    if (sString.startsWith("<?xml"))
+        return;
+
+    sal_Int32 nLength(0);
+    if (m_bAllowLineBreak)
+        nLength = m_pSaxWriterHelper->calcXMLByteLength(sString, false, false);
+
+    sal_Int32 nPrefix = getIndentPrefixLength(nLength);
+    if (nPrefix >= 0)
+        m_pSaxWriterHelper->insertIndentation(nPrefix);
+
+    if (!m_pSaxWriterHelper->writeString(sString, false, false))
+    {
+        throw SAXException("Invalid character during XML-Export", {}, {});
+    }
+}
+
+} // namespace
+
+extern "C" SAL_DLLPUBLIC_EXPORT css::uno::XInterface*
+com_sun_star_extensions_xml_sax_Writer_get_implementation(css::uno::XComponentContext*,
+                                                          css::uno::Sequence<css::uno::Any> const&)
+{
+    return cppu::acquire(new SAXWriter);
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */