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diff --git a/sc/source/ui/unoobj/scdetect.cxx b/sc/source/ui/unoobj/scdetect.cxx
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+++ b/sc/source/ui/unoobj/scdetect.cxx
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+/* -*- 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 "scdetect.hxx"
+
+#include <sal/macros.h>
+
+#include <com/sun/star/beans/PropertyValue.hpp>
+#include <com/sun/star/uno/XComponentContext.hpp>
+#include <cppuhelper/supportsservice.hxx>
+#include <com/sun/star/io/XInputStream.hpp>
+#include <unotools/mediadescriptor.hxx>
+#include <sfx2/docfile.hxx>
+#include <sfx2/docfilt.hxx>
+#include <sfx2/fcontnr.hxx>
+
+using namespace ::com::sun::star;
+using utl::MediaDescriptor;
+
+namespace {
+
+// table with search pattern
+// meaning of the sequences
+// 0x00??: the exact byte 0x?? must be at that place
+// 0x0100: read over a byte (don't care)
+// 0x02nn: a byte of 0xnn variations follows
+// 0x8000: recognition finished
+
+#define M_DC        0x0100
+#define M_ALT(CNT)  (0x0200+(CNT))
+#define M_END       0x8000
+
+const sal_uInt16 pLotus[] =      // Lotus 1/1A/2
+    { 0x0000, 0x0000, 0x0002, 0x0000,
+    M_ALT(2), 0x0004, 0x0006,
+    0x0004, M_END };
+
+const sal_uInt16 pLotusNew[] =   // Lotus >= 9.7
+    { 0x0000, 0x0000, M_DC, 0x0000,     // Rec# + Len (0x1a)
+      M_ALT(3), 0x0003, 0x0004, 0x0005, // File Revision Code 97->ME
+      0x0010, 0x0004, 0x0000, 0x0000,
+      M_END };
+
+const sal_uInt16 pLotus2[] =     // Lotus >3
+    { 0x0000, 0x0000, 0x001A, 0x0000,   // Rec# + Len (26)
+    M_ALT(2), 0x0000, 0x0002,         // File Revision Code
+    0x0010,
+    0x0004, 0x0000,                   // File Revision Subcode
+    M_END };
+
+const sal_uInt16 pQPro[] =
+       { 0x0000, 0x0000, 0x0002, 0x0000,
+         M_ALT(4), 0x0001, 0x0002, // WB1, WB2
+         0x0006, 0x0007,           // QPro 6/7 (?)
+         0x0010,
+         M_END };
+
+const sal_uInt16 pDIF1[] =       // DIF with CR-LF
+    {
+    'T', 'A', 'B', 'L', 'E',
+    M_DC, M_DC,
+    '0', ',', '1',
+    M_DC, M_DC,
+    '\"',
+    M_END };
+
+const sal_uInt16 pDIF2[] =       // DIF with CR or LF
+    {
+    'T', 'A', 'B', 'L', 'E',
+    M_DC,
+    '0', ',', '1',
+    M_DC,
+    '\"',
+    M_END };
+
+const sal_uInt16 pSylk[] =       // Sylk
+    {
+    'I', 'D', ';',
+    M_ALT(3), 'P', 'N', 'E',        // 'P' plus undocumented Excel extensions 'N' and 'E'
+    M_END };
+
+bool detectThisFormat(SvStream& rStr, const sal_uInt16* pSearch)
+{
+    sal_uInt8 nByte;
+    rStr.Seek( 0 ); // in the beginning everything was bad...
+    rStr.ReadUChar( nByte );
+    bool bSync = true;
+    while( !rStr.eof() && bSync )
+    {
+        sal_uInt16 nMuster = *pSearch;
+
+        if( nMuster < 0x0100 )
+        { // compare bytes
+            if( static_cast<sal_uInt8>(nMuster) != nByte )
+                bSync = false;
+        }
+        else if( nMuster & M_DC )
+        { // don't care
+        }
+        else if( nMuster & M_ALT(0) )
+        { // alternative Bytes
+            sal_uInt8 nCntAlt = static_cast<sal_uInt8>(nMuster);
+            bSync = false;          // first unsynchron
+            while( nCntAlt > 0 )
+            {
+                pSearch++;
+                if( static_cast<sal_uInt8>(*pSearch) == nByte )
+                    bSync = true;   // only now synchronization
+                nCntAlt--;
+            }
+        }
+        else if( nMuster & M_END )
+        { // Format detected
+            return true;
+        }
+
+        pSearch++;
+        rStr.ReadUChar( nByte );
+    }
+
+    return false;
+}
+
+}
+
+ScFilterDetect::ScFilterDetect()
+{
+}
+
+ScFilterDetect::~ScFilterDetect()
+{
+}
+
+#if 0
+// This method is no longer used, but I do want to keep this for now to see
+// if we could transfer this check to the now centralized ascii detection
+// code in the filter module.
+static sal_Bool lcl_MayBeAscii( SvStream& rStream )
+{
+    // ASCII/CSV is considered possible if there are no null bytes, or a Byte
+    // Order Mark is present, or if, for Unicode UCS2/UTF-16, all null bytes
+    // are on either even or uneven byte positions.
+
+    rStream.Seek(STREAM_SEEK_TO_BEGIN);
+
+    const size_t nBufSize = 2048;
+    sal_uInt16 aBuffer[ nBufSize ];
+    sal_uInt8* pByte = reinterpret_cast<sal_uInt8*>(aBuffer);
+    sal_uLong nBytesRead = rStream.Read( pByte, nBufSize*2);
+
+    if ( nBytesRead >= 2 && (aBuffer[0] == 0xfffe || aBuffer[0] == 0xfeff) )
+    {
+        // Unicode BOM file may contain null bytes.
+        return sal_True;
+    }
+
+    const sal_uInt16* p = aBuffer;
+    sal_uInt16 nMask = 0xffff;
+    nBytesRead /= 2;
+    while( nBytesRead-- && nMask )
+    {
+        sal_uInt16 nVal = *p++ & nMask;
+        if (!(nVal & 0x00ff))
+            nMask &= 0xff00;
+        if (!(nVal & 0xff00))
+            nMask &= 0x00ff;
+    }
+
+    return nMask != 0;
+}
+#endif
+
+static bool lcl_MayBeDBase( SvStream& rStream )
+{
+    // Look for dbf marker, see connectivity/source/inc/dbase/DTable.hxx
+    // DBFType for values.
+    const sal_uInt8 nValidMarks[] = {
+        0x03, 0x04, 0x05, 0x30, 0x31, 0x43, 0xB3, 0x83, 0x8b, 0x8e, 0xf5 };
+    sal_uInt8 nMark;
+    rStream.Seek(STREAM_SEEK_TO_BEGIN);
+    rStream.ReadUChar( nMark );
+    bool bValidMark = false;
+    for (size_t i=0; i < SAL_N_ELEMENTS(nValidMarks) && !bValidMark; ++i)
+    {
+        if (nValidMarks[i] == nMark)
+            bValidMark = true;
+    }
+    if ( !bValidMark )
+        return false;
+
+    const size_t nHeaderBlockSize = 32;
+    // Empty dbf is >= 32*2+1 bytes in size.
+    const size_t nEmptyDbf = nHeaderBlockSize * 2 + 1;
+
+    sal_uInt64 nSize = rStream.TellEnd();
+    if ( nSize < nEmptyDbf )
+        return false;
+
+    // count of records at 4
+    rStream.Seek(4);
+    sal_uInt32 nRecords(0);
+    rStream.ReadUInt32(nRecords);
+
+    // length of header starts at 8
+    rStream.Seek(8);
+    sal_uInt16 nHeaderLen;
+    rStream.ReadUInt16( nHeaderLen );
+
+    // size of record at 10
+    sal_uInt16 nRecordSize(0);
+    rStream.ReadUInt16(nRecordSize);
+
+    if ( nHeaderLen < nEmptyDbf || nSize < nHeaderLen )
+        return false;
+
+    // see DTable.cxx ODbaseTable::readHeader()
+    if (0 == nRecordSize)
+        return false;
+
+    // see DTable.cxx ODbaseTable::construct() line 546
+    if (0 == nRecords)
+    {
+        nRecords = (nSize - nHeaderLen) / nRecordSize;
+    }
+
+    // tdf#84834 sanity check of size
+    // tdf#106423: a dbf file can have 0 record, so no need to check nRecords
+    if (nSize < nHeaderLen + nRecords * sal_uInt64(nRecordSize))
+        return false;
+
+    // Last byte of header must be 0x0d, this is how it's specified.
+    // #i9581#,#i26407# but some applications don't follow the specification
+    // and pad the header with one byte 0x00 to reach an
+    // even boundary. Some (#i88577# ) even pad more or pad using a 0x1a ^Z
+    // control character (#i8857#). This results in:
+    // Last byte of header must be 0x0d on 32 bytes boundary.
+    sal_uInt16 nBlocks = (nHeaderLen - 1) / nHeaderBlockSize;
+    sal_uInt8 nEndFlag = 0;
+    while ( nBlocks > 1 && nEndFlag != 0x0d ) {
+        rStream.Seek( nBlocks-- * nHeaderBlockSize );
+        rStream.ReadUChar( nEndFlag );
+    }
+
+    return ( 0x0d == nEndFlag );
+}
+
+OUString SAL_CALL ScFilterDetect::detect( uno::Sequence<beans::PropertyValue>& lDescriptor )
+{
+    MediaDescriptor aMediaDesc( lDescriptor );
+    OUString aTypeName = aMediaDesc.getUnpackedValueOrDefault( MediaDescriptor::PROP_TYPENAME, OUString() );
+    uno::Reference< io::XInputStream > xStream ( aMediaDesc[MediaDescriptor::PROP_INPUTSTREAM], uno::UNO_QUERY );
+    if ( !xStream.is() )
+        return OUString();
+
+    SfxMedium aMedium;
+    aMedium.UseInteractionHandler( false );
+    aMedium.setStreamToLoadFrom( xStream, true );
+
+    SvStream* pStream = aMedium.GetInStream();
+    if ( !pStream || pStream->GetError() )
+        // No stream, no detection.
+        return OUString();
+
+    const char* pSearchFilterName = nullptr;
+    if (aTypeName == "calc_Lotus")
+    {
+        if (!detectThisFormat(*pStream, pLotus) && !detectThisFormat(*pStream, pLotusNew) && !detectThisFormat(*pStream, pLotus2))
+            return OUString();
+
+        pSearchFilterName = "Lotus";
+    }
+    else if (aTypeName == "calc_QPro")
+    {
+        if (!detectThisFormat(*pStream, pQPro))
+            return OUString();
+
+        pSearchFilterName = "Quattro Pro 6.0";
+    }
+    else if (aTypeName == "calc_SYLK")
+    {
+        if (!detectThisFormat(*pStream, pSylk))
+            return OUString();
+
+        pSearchFilterName = "SYLK";
+    }
+    else if (aTypeName == "calc_DIF")
+    {
+        if (!detectThisFormat(*pStream, pDIF1) && !detectThisFormat(*pStream, pDIF2))
+            return OUString();
+
+        pSearchFilterName = "DIF";
+    }
+    else if (aTypeName == "calc_dBase")
+    {
+        if (!lcl_MayBeDBase(*pStream))
+            return OUString();
+
+        pSearchFilterName = "dBase";
+    }
+    else
+        return OUString();
+
+    SfxFilterMatcher aMatcher("scalc");
+    std::shared_ptr<const SfxFilter> pFilter = aMatcher.GetFilter4FilterName(OUString::createFromAscii(pSearchFilterName));
+
+    if (!pFilter)
+        return OUString();
+
+    aMediaDesc[MediaDescriptor::PROP_FILTERNAME] <<= pFilter->GetName();
+    aMediaDesc >> lDescriptor;
+    return aTypeName;
+}
+
+OUString SAL_CALL ScFilterDetect::getImplementationName()
+{
+    return "com.sun.star.comp.calc.FormatDetector";
+}
+
+sal_Bool ScFilterDetect::supportsService( const OUString& sServiceName )
+{
+    return cppu::supportsService(this, sServiceName);
+}
+
+css::uno::Sequence<OUString> ScFilterDetect::getSupportedServiceNames()
+{
+    return { "com.sun.star.frame.ExtendedTypeDetection" };
+}
+
+extern "C" SAL_DLLPUBLIC_EXPORT css::uno::XInterface*
+com_sun_star_comp_calc_FormatDetector_get_implementation(css::uno::XComponentContext* /*context*/,
+                                                         css::uno::Sequence<css::uno::Any> const &)
+{
+    return cppu::acquire(new ScFilterDetect);
+}
+
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */