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, 844 insertions, 0 deletions

diff --git a/sax/source/tools/fastserializer.cxx b/sax/source/tools/fastserializer.cxx
new file mode 100644
index 0000000000..0a5c227b72
--- /dev/null
+++ b/sax/source/tools/fastserializer.cxx
@@ -0,0 +1,844 @@
+/* -*- 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 "fastserializer.hxx"
+
+#include <com/sun/star/xml/sax/FastTokenHandler.hpp>
+#include <rtl/math.h>
+#include <sal/log.hxx>
+#include <comphelper/processfactory.hxx>
+
+#include <cassert>
+#include <optional>
+#include <string.h>
+#include <string_view>
+#include <utility>
+
+#if OSL_DEBUG_LEVEL > 0
+#include <iostream>
+#include <set>
+#endif
+
+using ::std::vector;
+using ::com::sun::star::uno::Sequence;
+using ::com::sun::star::io::XOutputStream;
+
+#define HAS_NAMESPACE(x) ((x & 0xffff0000) != 0)
+#define NAMESPACE(x) (x >> 16)
+#define TOKEN(x) (x & 0xffff)
+// number of characters without terminating 0
+#define N_CHARS(string) (SAL_N_ELEMENTS(string) - 1)
+
+const char sClosingBracket[] = ">";
+const char sSlashAndClosingBracket[] = "/>";
+constexpr OString sColon = ":"_ostr;
+const char sOpeningBracket[] = "<";
+const char sOpeningBracketAndSlash[] = "</";
+const char sQuote[] = "\"";
+const char sEqualSignAndQuote[] = "=\"";
+const char sSpace[] = " ";
+const char sXmlHeader[] = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>\n";
+
+namespace sax_fastparser {
+    FastSaxSerializer::FastSaxSerializer( const css::uno::Reference< css::io::XOutputStream >& xOutputStream )
+        : mbMarkStackEmpty(true)
+        , mpDoubleStr(nullptr)
+        , mnDoubleStrCapacity(RTL_STR_MAX_VALUEOFDOUBLE)
+        , mbXescape(true)
+    {
+        rtl_string_new_WithLength(&mpDoubleStr, mnDoubleStrCapacity);
+        mxFastTokenHandler = css::xml::sax::FastTokenHandler::create(
+                ::comphelper::getProcessComponentContext());
+        assert(xOutputStream.is()); // cannot do anything without that
+        maCachedOutputStream.setOutputStream( xOutputStream );
+    }
+
+    FastSaxSerializer::~FastSaxSerializer()
+    {
+        rtl_string_release(mpDoubleStr);
+    }
+
+    void FastSaxSerializer::startDocument()
+    {
+        writeBytes(sXmlHeader, N_CHARS(sXmlHeader));
+    }
+
+    void FastSaxSerializer::write( double value )
+    {
+        rtl_math_doubleToString(
+            &mpDoubleStr, &mnDoubleStrCapacity, 0, value, rtl_math_StringFormat_G,
+            RTL_STR_MAX_VALUEOFDOUBLE - RTL_CONSTASCII_LENGTH("-x.E-xxx"), '.', nullptr,
+            0, true);
+
+        write(mpDoubleStr->buffer, mpDoubleStr->length);
+        // and "clear" the string
+        mpDoubleStr->length = 0;
+        mnDoubleStrCapacity = RTL_STR_MAX_VALUEOFDOUBLE;
+    }
+
+    void FastSaxSerializer::write( std::u16string_view sOutput, bool bEscape )
+    {
+        write( OUStringToOString(sOutput, RTL_TEXTENCODING_UTF8), bEscape );
+
+    }
+
+    void FastSaxSerializer::write( std::string_view sOutput, bool bEscape )
+    {
+        write( sOutput.data(), sOutput.length(), bEscape );
+    }
+
+    /** Characters not allowed in XML 1.0
+        XML 1.1 would exclude only U+0000
+
+        This assumes that `string` is UTF-8, but which appears to generally be the case:  The only
+        user of this FastSaxSerializer code is FastSerializerHelper, and when its constructor
+        (sax/source/tools/fshelper.cxx) is called with bWriteHeader being true, it calls
+        FastSaxSerializer::startDocument, which writes sXmlHeader claiming encoding="UTF-8".  The
+        only place that appears to construct FastSerializerHelper appears to be
+        XmlFilterBase::openFragmentStreamWithSerializer (oox/source/core/xmlfilterbase.cxx), and it
+        only passes false for bWriteHeader when the given rMediaType contains "vml" but not "+xml"
+        (see <https://git.libreoffice.org/core/+/6a11add2c4ea975356cfb7bab02301788c79c904%5E!/>
+        "XLSX VML Export fixes", stating "Don't write xml headers for vml files").  But lets assume
+        that even such Vector Markup Language files are written as UTF-8.
+     */
+    template<typename Int> static std::optional<std::pair<unsigned, Int>> invalidChar(
+        char const * string, Int length, Int index )
+    {
+        assert(index < length);
+        auto const c = string[index];
+
+        if (static_cast<unsigned char>(c) >= 0x20 && c != '\xEF')
+            return {};
+
+        switch (c)
+        {
+            case 0x09:
+            case 0x0a:
+            case 0x0d:
+                return {};
+            case '\xEF': // U+FFFE, U+FFFF:
+                if (length - index >= 3 && string[index + 1] == '\xBF') {
+                    switch (string[index + 2]) {
+                    case '\xBE':
+                        return std::pair(0xFFFE, 3);
+                    case '\xBF':
+                        return std::pair(0xFFFF, 3);
+                    }
+                }
+                return {};
+        }
+        return std::pair(static_cast<unsigned char>(c), 1);
+    }
+
+    static bool isHexDigit( char c )
+    {
+        return ('0' <= c && c <= '9') || ('A' <= c && c <= 'F') || ('a' <= c && c <= 'f');
+    }
+
+    void FastSaxSerializer::write( const char* pStr, sal_Int32 nLen, bool bEscape )
+    {
+        if (nLen == -1)
+            nLen = pStr ? strlen(pStr) : 0;
+
+        if (!bEscape)
+        {
+            writeBytes( pStr, nLen );
+            return;
+        }
+
+        bool bGood = true;
+        const sal_Int32 kXescapeLen = 7;
+        char bufXescape[kXescapeLen+1];
+        sal_Int32 nNextXescape = 0;
+        for (sal_Int32 i = 0; i < nLen;)
+        {
+            char c = pStr[ i ];
+            switch( c )
+            {
+                case '<':   writeBytes( "&lt;", 4 );     break;
+                case '>':   writeBytes( "&gt;", 4 );     break;
+                case '&':   writeBytes( "&amp;", 5 );    break;
+                case '\'':  writeBytes( "&apos;", 6 );   break;
+                case '"':   writeBytes( "&quot;", 6 );   break;
+                case '\t':
+#if 0
+                            // Seems OOXML prefers the _xHHHH_ escape over the
+                            // entity in *some* cases, apparently in attribute
+                            // values but not in element data.
+                            // Would need to distinguish at a higher level.
+                            if (mbXescape)
+                            {
+                                snprintf( bufXescape, kXescapeLen+1, "_x%04x_",
+                                        static_cast<unsigned int>(static_cast<unsigned char>(c)));
+                                writeBytes( bufXescape, kXescapeLen);
+                            }
+                            else
+#endif
+                            {
+                                writeBytes( "&#9;", 4 );
+                            }
+                break;
+                case '\n':
+#if 0
+                            if (mbXescape)
+                            {
+                                snprintf( bufXescape, kXescapeLen+1, "_x%04x_",
+                                        static_cast<unsigned int>(static_cast<unsigned char>(c)));
+                                writeBytes( bufXescape, kXescapeLen);
+                            }
+                            else
+#endif
+                            {
+                                writeBytes( "&#10;", 5 );
+                            }
+                break;
+                case '\r':
+#if 0
+                            if (mbXescape)
+                            {
+                                snprintf( bufXescape, kXescapeLen+1, "_x%04x_",
+                                        static_cast<unsigned int>(static_cast<unsigned char>(c)));
+                                writeBytes( bufXescape, kXescapeLen);
+                            }
+                            else
+#endif
+                            {
+                                writeBytes( "&#13;", 5 );
+                            }
+                break;
+                default:
+                            if (mbXescape)
+                            {
+                                char c1, c2, c3, c4;
+                                // Escape characters not valid in XML 1.0 as
+                                // _xHHHH_. A literal "_xHHHH_" has to be
+                                // escaped as _x005F_xHHHH_ (effectively
+                                // escaping the leading '_').
+                                // See ECMA-376-1:2016 page 3736,
+                                // 22.4.2.4 bstr (Basic String)
+                                // for reference.
+                                if (c == '_' && i >= nNextXescape && i <= nLen - kXescapeLen &&
+                                        pStr[i+6] == '_' &&
+                                        ((pStr[i+1] | 0x20) == 'x') &&
+                                        isHexDigit( c1 = pStr[i+2] ) &&
+                                        isHexDigit( c2 = pStr[i+3] ) &&
+                                        isHexDigit( c3 = pStr[i+4] ) &&
+                                        isHexDigit( c4 = pStr[i+5] ))
+                                {
+                                    // OOXML has the odd habit to write some
+                                    // names using this that when re-saving
+                                    // should *not* be escaped, specifically
+                                    // _x0020_ for blanks in w:xpath values.
+                                    if (!(c1 == '0' && c2 == '0' && c3 == '2' && c4 == '0'))
+                                    {
+                                        // When encountering "_x005F_xHHHH_"
+                                        // assume that is an already escaped
+                                        // sequence that was not unescaped and
+                                        // shall be written as is, to not end
+                                        // up with "_x005F_x005F_xHHHH_" and
+                                        // repeated...
+                                        if (c1 == '0' && c2 == '0' && c3 == '5' && (c4 | 0x20) == 'f' &&
+                                                i + kXescapeLen <= nLen - 6 &&
+                                                pStr[i+kXescapeLen+5] == '_' &&
+                                                ((pStr[i+kXescapeLen+0] | 0x20) == 'x') &&
+                                                isHexDigit( pStr[i+kXescapeLen+1] ) &&
+                                                isHexDigit( pStr[i+kXescapeLen+2] ) &&
+                                                isHexDigit( pStr[i+kXescapeLen+3] ) &&
+                                                isHexDigit( pStr[i+kXescapeLen+4] ))
+                                        {
+                                            writeBytes( &c, 1 );
+                                            // Remember this fake escapement.
+                                            nNextXescape = i + kXescapeLen + 6;
+                                        }
+                                        else
+                                        {
+                                            writeBytes( "_x005F_", kXescapeLen);
+                                            // Remember this escapement so in
+                                            // _xHHHH_xHHHH_ only the first '_'
+                                            // is escaped.
+                                            nNextXescape = i + kXescapeLen;
+                                        }
+                                        break;
+                                    }
+                                }
+                                if (auto const inv = invalidChar(pStr, nLen, i))
+                                {
+                                    snprintf( bufXescape, kXescapeLen+1, "_x%04x_",
+                                            inv->first);
+                                    writeBytes( bufXescape, kXescapeLen);
+                                    i += inv->second;
+                                    continue;
+                                }
+                            }
+#if OSL_DEBUG_LEVEL > 0
+                            else
+                            {
+                                if (bGood && invalidChar(pStr, nLen, i))
+                                {
+                                    bGood = false;
+                                    // The SAL_WARN() for the single character is
+                                    // issued in writeBytes(), just gather for the
+                                    // SAL_WARN_IF() below.
+                                }
+                            }
+#endif
+                            writeBytes( &c, 1 );
+                break;
+            }
+            ++i;
+        }
+        SAL_WARN_IF( !bGood && nLen > 1, "sax", "in '" << OString(pStr,std::min<sal_Int32>(nLen,42)) << "'");
+    }
+
+    void FastSaxSerializer::endDocument()
+    {
+        assert(mbMarkStackEmpty && maMarkStack.empty());
+        maCachedOutputStream.flush();
+    }
+
+    void FastSaxSerializer::writeId( ::sal_Int32 nElement )
+    {
+        if( HAS_NAMESPACE( nElement ) ) {
+            auto const Namespace(mxFastTokenHandler->getUTF8Identifier(NAMESPACE(nElement)));
+            assert(Namespace.hasElements());
+            writeBytes(Namespace);
+            writeBytes(sColon.getStr(), sColon.getLength());
+            auto const Element(mxFastTokenHandler->getUTF8Identifier(TOKEN(nElement)));
+            assert(Element.hasElements());
+            writeBytes(Element);
+        } else {
+            auto const Element(mxFastTokenHandler->getUTF8Identifier(nElement));
+            assert(Element.hasElements());
+            writeBytes(Element);
+        }
+    }
+
+#ifdef DBG_UTIL
+    OString FastSaxSerializer::getId( ::sal_Int32 nElement )
+    {
+        if (HAS_NAMESPACE(nElement)) {
+            Sequence<sal_Int8> const ns(
+                mxFastTokenHandler->getUTF8Identifier(NAMESPACE(nElement)));
+            Sequence<sal_Int8> const name(
+                mxFastTokenHandler->getUTF8Identifier(TOKEN(nElement)));
+            return std::string_view(
+                     reinterpret_cast<char const*>(ns.getConstArray()), ns.getLength())
+                 + sColon
+                 + std::string_view(
+                     reinterpret_cast<char const*>(name.getConstArray()), name.getLength());
+        } else {
+            Sequence<sal_Int8> const name(
+                mxFastTokenHandler->getUTF8Identifier(nElement));
+            return OString(reinterpret_cast<char const*>(name.getConstArray()), name.getLength());
+        }
+    }
+#endif
+
+    void FastSaxSerializer::startFastElement( ::sal_Int32 Element, FastAttributeList const * pAttrList )
+    {
+        if ( !mbMarkStackEmpty )
+        {
+            maCachedOutputStream.flush();
+            maMarkStack.top()->setCurrentElement( Element );
+        }
+
+#ifdef DBG_UTIL
+        if (mbMarkStackEmpty)
+            m_DebugStartedElements.push(Element);
+        else
+            maMarkStack.top()->m_DebugStartedElements.push_back(Element);
+#endif
+
+        writeBytes(sOpeningBracket, N_CHARS(sOpeningBracket));
+
+        writeId(Element);
+        if (pAttrList)
+            writeFastAttributeList(*pAttrList);
+        else
+            writeTokenValueList();
+
+        writeBytes(sClosingBracket, N_CHARS(sClosingBracket));
+    }
+
+    void FastSaxSerializer::endFastElement( ::sal_Int32 Element )
+    {
+#ifdef DBG_UTIL
+        // Well-formedness constraint: Element Type Match
+        if (mbMarkStackEmpty)
+        {
+            assert(!m_DebugStartedElements.empty());
+            assert(Element == m_DebugStartedElements.top());
+            m_DebugStartedElements.pop();
+        }
+        else
+        {
+            if (dynamic_cast<ForSort*>(maMarkStack.top().get()))
+            {
+                // Sort is always well-formed fragment
+                assert(!maMarkStack.top()->m_DebugStartedElements.empty());
+            }
+            if (maMarkStack.top()->m_DebugStartedElements.empty())
+            {
+                maMarkStack.top()->m_DebugEndedElements.push_back(Element);
+            }
+            else
+            {
+                assert(Element == maMarkStack.top()->m_DebugStartedElements.back());
+                maMarkStack.top()->m_DebugStartedElements.pop_back();
+            }
+        }
+#endif
+
+        writeBytes(sOpeningBracketAndSlash, N_CHARS(sOpeningBracketAndSlash));
+
+        writeId(Element);
+
+        writeBytes(sClosingBracket, N_CHARS(sClosingBracket));
+    }
+
+    void FastSaxSerializer::singleFastElement( ::sal_Int32 Element, FastAttributeList const * pAttrList )
+    {
+        if ( !mbMarkStackEmpty )
+        {
+            maCachedOutputStream.flush();
+            maMarkStack.top()->setCurrentElement( Element );
+        }
+
+        writeBytes(sOpeningBracket, N_CHARS(sOpeningBracket));
+
+        writeId(Element);
+        if (pAttrList)
+            writeFastAttributeList(*pAttrList);
+        else
+            writeTokenValueList();
+
+        writeBytes(sSlashAndClosingBracket, N_CHARS(sSlashAndClosingBracket));
+    }
+
+    css::uno::Reference< css::io::XOutputStream > const & FastSaxSerializer::getOutputStream() const
+    {
+        return maCachedOutputStream.getOutputStream();
+    }
+
+    void FastSaxSerializer::writeTokenValueList()
+    {
+#ifdef DBG_UTIL
+        ::std::set<OString> DebugAttributes;
+#endif
+        for (const TokenValue & rTokenValue : maTokenValues)
+        {
+            writeBytes(sSpace, N_CHARS(sSpace));
+
+            sal_Int32 nToken = rTokenValue.nToken;
+            writeId(nToken);
+
+#ifdef DBG_UTIL
+            // Well-formedness constraint: Unique Att Spec
+            OString const nameId(getId(nToken));
+            assert(DebugAttributes.find(nameId) == DebugAttributes.end());
+            DebugAttributes.insert(nameId);
+#endif
+
+            writeBytes(sEqualSignAndQuote, N_CHARS(sEqualSignAndQuote));
+
+            write(rTokenValue.pValue, -1, true);
+
+            writeBytes(sQuote, N_CHARS(sQuote));
+        }
+        maTokenValues.clear();
+    }
+
+    void FastSaxSerializer::writeFastAttributeList(FastAttributeList const & rAttrList)
+    {
+#ifdef DBG_UTIL
+        ::std::set<OString> DebugAttributes;
+#endif
+        const std::vector< sal_Int32 >& Tokens = rAttrList.getFastAttributeTokens();
+        for (size_t j = 0; j < Tokens.size(); j++)
+        {
+            writeBytes(sSpace, N_CHARS(sSpace));
+
+            sal_Int32 nToken = Tokens[j];
+            writeId(nToken);
+
+#ifdef DBG_UTIL
+            // Well-formedness constraint: Unique Att Spec
+            OString const nameId(getId(nToken));
+            SAL_WARN_IF(DebugAttributes.find(nameId) != DebugAttributes.end(),  "sax", "Duplicate attribute: " << nameId );
+            assert(DebugAttributes.find(nameId) == DebugAttributes.end());
+            DebugAttributes.insert(nameId);
+#endif
+
+            writeBytes(sEqualSignAndQuote, N_CHARS(sEqualSignAndQuote));
+
+            const char* pAttributeValue = rAttrList.getFastAttributeValue(j);
+
+            // tdf#117274 don't escape the special VML shape type id "#_x0000_t202"
+            bool bEscape = !(pAttributeValue
+                    && *pAttributeValue != '\0'
+                    && (*pAttributeValue == '#'
+                        ? strncmp(pAttributeValue, "#_x0000_t", 9) == 0
+                        : strncmp(pAttributeValue, "_x0000_t", 8) == 0));
+
+            write(pAttributeValue, rAttrList.AttributeValueLength(j), bEscape);
+
+            writeBytes(sQuote, N_CHARS(sQuote));
+        }
+    }
+
+    void FastSaxSerializer::mark(sal_Int32 const nTag, const Int32Sequence& rOrder)
+    {
+        if (rOrder.hasElements())
+        {
+            auto pSort = std::make_shared<ForSort>(nTag, rOrder);
+            maMarkStack.push( pSort );
+            maCachedOutputStream.setOutput( pSort );
+        }
+        else
+        {
+            auto pMerge = std::make_shared<ForMerge>(nTag);
+            maMarkStack.push( pMerge );
+            maCachedOutputStream.setOutput( pMerge );
+        }
+        mbMarkStackEmpty = false;
+    }
+
+#ifdef DBG_UTIL
+    static void lcl_DebugMergeAppend(
+            std::deque<sal_Int32> & rLeftEndedElements,
+            std::deque<sal_Int32> & rLeftStartedElements,
+            std::deque<sal_Int32> & rRightEndedElements,
+            std::deque<sal_Int32> & rRightStartedElements)
+    {
+        while (!rRightEndedElements.empty())
+        {
+            if (rLeftStartedElements.empty())
+            {
+                rLeftEndedElements.push_back(rRightEndedElements.front());
+            }
+            else
+            {
+                assert(rLeftStartedElements.back() == rRightEndedElements.front());
+                rLeftStartedElements.pop_back();
+            }
+            rRightEndedElements.pop_front();
+        }
+        while (!rRightStartedElements.empty())
+        {
+            rLeftStartedElements.push_back(rRightStartedElements.front());
+            rRightStartedElements.pop_front();
+        }
+    }
+
+    static void lcl_DebugMergePrepend(
+            std::deque<sal_Int32> & rLeftEndedElements,
+            std::deque<sal_Int32> & rLeftStartedElements,
+            std::deque<sal_Int32> & rRightEndedElements,
+            std::deque<sal_Int32> & rRightStartedElements)
+    {
+        while (!rLeftStartedElements.empty())
+        {
+            if (rRightEndedElements.empty())
+            {
+                rRightStartedElements.push_front(rLeftStartedElements.back());
+            }
+            else
+            {
+                assert(rRightEndedElements.front() == rLeftStartedElements.back());
+                rRightEndedElements.pop_front();
+            }
+            rLeftStartedElements.pop_back();
+        }
+        while (!rLeftEndedElements.empty())
+        {
+            rRightEndedElements.push_front(rLeftEndedElements.back());
+            rLeftEndedElements.pop_back();
+        }
+    }
+#endif
+
+    void FastSaxSerializer::mergeTopMarks(
+        sal_Int32 const nTag, sax_fastparser::MergeMarks const eMergeType)
+    {
+        SAL_WARN_IF(mbMarkStackEmpty, "sax", "Empty mark stack - nothing to merge");
+        assert(!mbMarkStackEmpty); // should never happen
+        if ( mbMarkStackEmpty )
+            return;
+
+        assert(maMarkStack.top()->m_Tag == nTag && "mark/merge tag mismatch!");
+        (void) nTag;
+#ifdef DBG_UTIL
+        if (dynamic_cast<ForSort*>(maMarkStack.top().get()))
+        {
+            // Sort is always well-formed fragment
+            assert(maMarkStack.top()->m_DebugStartedElements.empty());
+            assert(maMarkStack.top()->m_DebugEndedElements.empty());
+        }
+        lcl_DebugMergeAppend(
+            maMarkStack.top()->m_DebugEndedElements,
+            maMarkStack.top()->m_DebugStartedElements,
+            maMarkStack.top()->m_DebugPostponedEndedElements,
+            maMarkStack.top()->m_DebugPostponedStartedElements);
+#endif
+
+        // flush, so that we get everything in getData()
+        maCachedOutputStream.flush();
+
+        if (maMarkStack.size() == 1)
+        {
+#ifdef DBG_UTIL
+            while (!maMarkStack.top()->m_DebugEndedElements.empty())
+            {
+                assert(maMarkStack.top()->m_DebugEndedElements.front() == m_DebugStartedElements.top());
+                maMarkStack.top()->m_DebugEndedElements.pop_front();
+                m_DebugStartedElements.pop();
+            }
+            while (!maMarkStack.top()->m_DebugStartedElements.empty())
+            {
+                m_DebugStartedElements.push(maMarkStack.top()->m_DebugStartedElements.front());
+                maMarkStack.top()->m_DebugStartedElements.pop_front();
+            }
+#endif
+            Sequence<sal_Int8> aSeq( maMarkStack.top()->getData() );
+            maMarkStack.pop();
+            mbMarkStackEmpty = true;
+            maCachedOutputStream.resetOutputToStream();
+            maCachedOutputStream.writeBytes( aSeq.getConstArray(), aSeq.getLength() );
+            return;
+        }
+
+#ifdef DBG_UTIL
+        ::std::deque<sal_Int32> topDebugStartedElements(maMarkStack.top()->m_DebugStartedElements);
+        ::std::deque<sal_Int32> topDebugEndedElements(maMarkStack.top()->m_DebugEndedElements);
+#endif
+        const Int8Sequence aMerge( maMarkStack.top()->getData() );
+        maMarkStack.pop();
+#ifdef DBG_UTIL
+        switch (eMergeType)
+        {
+            case MergeMarks::APPEND:
+                lcl_DebugMergeAppend(
+                    maMarkStack.top()->m_DebugEndedElements,
+                    maMarkStack.top()->m_DebugStartedElements,
+                    topDebugEndedElements,
+                    topDebugStartedElements);
+                break;
+            case MergeMarks::PREPEND:
+                if (dynamic_cast<ForSort*>(maMarkStack.top().get())) // argh...
+                {
+                    lcl_DebugMergeAppend(
+                        maMarkStack.top()->m_DebugEndedElements,
+                        maMarkStack.top()->m_DebugStartedElements,
+                        topDebugEndedElements,
+                        topDebugStartedElements);
+                }
+                else
+                {
+                    lcl_DebugMergePrepend(
+                        topDebugEndedElements,
+                        topDebugStartedElements,
+                        maMarkStack.top()->m_DebugEndedElements,
+                        maMarkStack.top()->m_DebugStartedElements);
+                }
+                break;
+            case MergeMarks::POSTPONE:
+                lcl_DebugMergeAppend(
+                    maMarkStack.top()->m_DebugPostponedEndedElements,
+                    maMarkStack.top()->m_DebugPostponedStartedElements,
+                    topDebugEndedElements,
+                    topDebugStartedElements);
+                break;
+        }
+#endif
+        if (maMarkStack.empty())
+        {
+            mbMarkStackEmpty = true;
+            maCachedOutputStream.resetOutputToStream();
+        }
+        else
+        {
+            maCachedOutputStream.setOutput( maMarkStack.top() );
+        }
+
+        switch ( eMergeType )
+        {
+            case MergeMarks::APPEND:   maMarkStack.top()->append( aMerge );   break;
+            case MergeMarks::PREPEND:  maMarkStack.top()->prepend( aMerge );  break;
+            case MergeMarks::POSTPONE: maMarkStack.top()->postpone( aMerge ); break;
+        }
+    }
+
+    void FastSaxSerializer::writeBytes( const Sequence< sal_Int8 >& rData )
+    {
+        maCachedOutputStream.writeBytes( rData.getConstArray(), rData.getLength() );
+    }
+
+    void FastSaxSerializer::writeBytes( const char* pStr, size_t nLen )
+    {
+#if OSL_DEBUG_LEVEL > 0
+        {
+            bool bGood = true;
+            for (size_t i=0; i < nLen;)
+            {
+                if (auto const inv = invalidChar(pStr, nLen, i))
+                {
+                    bGood = false;
+                    SAL_WARN("sax", "FastSaxSerializer::writeBytes - illegal XML character 0x" <<
+                            std::hex << inv->first);
+                    i += inv->second;
+                    continue;
+                }
+                ++i;
+            }
+            SAL_WARN_IF( !bGood && nLen > 1, "sax", "in '" << OString(pStr,std::min<sal_Int32>(nLen,42)) << "'");
+        }
+#endif
+        maCachedOutputStream.writeBytes( reinterpret_cast<const sal_Int8*>(pStr), nLen );
+    }
+
+    FastSaxSerializer::Int8Sequence& FastSaxSerializer::ForMerge::getData()
+    {
+        merge( maData, maPostponed, true );
+        maPostponed.realloc( 0 );
+
+        return maData;
+    }
+
+#if OSL_DEBUG_LEVEL > 0
+    void FastSaxSerializer::ForMerge::print( )
+    {
+        std::cerr << "Data: ";
+        for ( sal_Int32 i=0, len=maData.getLength(); i < len; i++ )
+        {
+            std::cerr << maData[i];
+        }
+
+        std::cerr << "\nPostponed: ";
+        for ( sal_Int32 i=0, len=maPostponed.getLength(); i < len; i++ )
+        {
+            std::cerr << maPostponed[i];
+        }
+
+        std::cerr << "\n";
+    }
+#endif
+
+    void FastSaxSerializer::ForMerge::prepend( const Int8Sequence &rWhat )
+    {
+        merge( maData, rWhat, false );
+    }
+
+    void FastSaxSerializer::ForMerge::append( const css::uno::Sequence<sal_Int8> &rWhat )
+    {
+        merge( maData, rWhat, true );
+    }
+
+    void FastSaxSerializer::ForMerge::postpone( const Int8Sequence &rWhat )
+    {
+        merge( maPostponed, rWhat, true );
+    }
+
+    void FastSaxSerializer::ForMerge::merge( Int8Sequence &rTop, const Int8Sequence &rMerge, bool bAppend )
+    {
+        sal_Int32 nMergeLen = rMerge.getLength();
+        if ( nMergeLen <= 0 )
+            return;
+
+        sal_Int32 nTopLen = rTop.getLength();
+
+        rTop.realloc( nTopLen + nMergeLen );
+        if ( bAppend )
+        {
+            // append the rMerge to the rTop
+            memcpy( rTop.getArray() + nTopLen, rMerge.getConstArray(), nMergeLen );
+        }
+        else
+        {
+            // prepend the rMerge to the rTop
+            memmove( rTop.getArray() + nMergeLen, rTop.getConstArray(), nTopLen );
+            memcpy( rTop.getArray(), rMerge.getConstArray(), nMergeLen );
+        }
+    }
+
+    void FastSaxSerializer::ForMerge::resetData( )
+    {
+        maData = Int8Sequence();
+    }
+
+    void FastSaxSerializer::ForSort::setCurrentElement( sal_Int32 nElement )
+    {
+        const auto & rOrder = maOrder;
+        if( std::find( rOrder.begin(), rOrder.end(), nElement ) != rOrder.end() )
+        {
+            mnCurrentElement = nElement;
+            if ( maData.find( nElement ) == maData.end() )
+                maData[ nElement ] = Int8Sequence();
+        }
+    }
+
+    void FastSaxSerializer::ForSort::prepend( const Int8Sequence &rWhat )
+    {
+        append( rWhat );
+    }
+
+    void FastSaxSerializer::ForSort::append( const css::uno::Sequence<sal_Int8> &rWhat )
+    {
+        merge( maData[mnCurrentElement], rWhat, true );
+    }
+
+    void FastSaxSerializer::ForSort::sort()
+    {
+        // Clear the ForMerge data to avoid duplicate items
+        resetData();
+
+        // Sort it all
+        std::map< sal_Int32, Int8Sequence >::iterator iter;
+        for ( const auto nIndex : std::as_const(maOrder) )
+        {
+            iter = maData.find( nIndex );
+            if ( iter != maData.end() )
+                ForMerge::append( iter->second );
+        }
+    }
+
+    FastSaxSerializer::Int8Sequence& FastSaxSerializer::ForSort::getData()
+    {
+        sort( );
+        return ForMerge::getData();
+    }
+
+#if OSL_DEBUG_LEVEL > 0
+    void FastSaxSerializer::ForSort::print( )
+    {
+        for ( const auto& [rElement, rData] : maData )
+        {
+            std::cerr << "pair: " << rElement;
+            for ( sal_Int32 i=0, len=rData.getLength(); i < len; ++i )
+                std::cerr << rData[i];
+            std::cerr << "\n";
+        }
+
+        sort( );
+        ForMerge::print();
+    }
+#endif
+
+} // namespace sax_fastparser
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */