filter/source/config/fragments/types/emf_MS_Windows_Metafile.xcu | 2 filter/source/config/fragments/types/wmf_MS_Windows_Metafile.xcu | 2 include/tools/zcodec.hxx | 6 tools/source/zcodec/zcodec.cxx | 23 ++- vcl/inc/graphic/GraphicFormatDetector.hxx | 13 + vcl/qa/cppunit/GraphicFormatDetectorTest.cxx | 51 +++++++ vcl/qa/cppunit/data/TypeDetectionExample.emf |binary vcl/qa/cppunit/data/TypeDetectionExample.emz |binary vcl/qa/cppunit/data/TypeDetectionExample.wmz |binary vcl/source/filter/GraphicFormatDetector.cxx | 68 ++++++---- vcl/source/filter/graphicfilter.cxx | 44 +++++- vcl/source/filter/graphicfilter2.cxx | 50 ------- 12 files changed, 170 insertions(+), 89 deletions(-)
New commits: commit e9c50fbbc3b07ef927d133da9cf2395c55611e0f Author: offtkp <[email protected]> AuthorDate: Sat Apr 2 15:49:32 2022 +0300 Commit: Tomaž Vajngerl <[email protected]> CommitDate: Fri May 6 04:02:05 2022 +0200 tdf#103954: Z compressed graphic formats support for EMF/WMF - Added .emz and .wmz file opening support - Added a function to check for Z compression that all z comp. formats can use - Added 3 unit tests for emf/emz/wmz files and the example files have been checked with a different tool (File Viewer 4) - emf/emz file detection changed from magic byte checking to extension checking, like wmf/wmz does Change-Id: I3e433fd23d18482648a51cd04b8f467368e97b62 Reviewed-on: https://gerrit.libreoffice.org/c/core/+/132456 Tested-by: Jenkins Reviewed-by: Tomaž Vajngerl <[email protected]> diff --git a/filter/source/config/fragments/types/emf_MS_Windows_Metafile.xcu b/filter/source/config/fragments/types/emf_MS_Windows_Metafile.xcu index 6d1564bebd07..2003217aad30 100644 --- a/filter/source/config/fragments/types/emf_MS_Windows_Metafile.xcu +++ b/filter/source/config/fragments/types/emf_MS_Windows_Metafile.xcu @@ -18,7 +18,7 @@ <node oor:name="emf_MS_Windows_Metafile" oor:op="replace" > <prop oor:name="DetectService"><value>com.sun.star.comp.draw.FormatDetector</value></prop> <prop oor:name="URLPattern"/> - <prop oor:name="Extensions"><value>emf</value></prop> + <prop oor:name="Extensions"><value>emf emz</value></prop> <prop oor:name="MediaType"><value>image/x-emf</value></prop> <prop oor:name="Preferred"><value>false</value></prop> <prop oor:name="PreferredFilter"><value>EMF - MS Windows Metafile</value></prop> diff --git a/filter/source/config/fragments/types/wmf_MS_Windows_Metafile.xcu b/filter/source/config/fragments/types/wmf_MS_Windows_Metafile.xcu index 54c6bf54c33b..7564dd057cf4 100644 --- a/filter/source/config/fragments/types/wmf_MS_Windows_Metafile.xcu +++ b/filter/source/config/fragments/types/wmf_MS_Windows_Metafile.xcu @@ -18,7 +18,7 @@ <node oor:name="wmf_MS_Windows_Metafile" oor:op="replace" > <prop oor:name="DetectService"><value>com.sun.star.comp.draw.FormatDetector</value></prop> <prop oor:name="URLPattern"/> - <prop oor:name="Extensions"><value>wmf</value></prop> + <prop oor:name="Extensions"><value>wmf wmz</value></prop> <prop oor:name="MediaType"><value>image/x-wmf</value></prop> <prop oor:name="Preferred"><value>false</value></prop> <prop oor:name="PreferredFilter"><value>WMF - MS Windows Metafile</value></prop> diff --git a/include/tools/zcodec.hxx b/include/tools/zcodec.hxx index c9c71bf752b1..745d44e9199e 100644 --- a/include/tools/zcodec.hxx +++ b/include/tools/zcodec.hxx @@ -59,6 +59,12 @@ class SAL_WARN_UNUSED TOOLS_DLLPUBLIC ZCodec public: ZCodec( size_t nInBufSize = 32768, size_t nOutBufSize = 32768 ); ~ZCodec(); + /** + * @brief Checks whether a stream is Z compressed + * + * @param rIStm the stream to check + */ + static bool IsZCompressed( SvStream& rIStm ); void BeginCompression( int nCompressLevel = ZCODEC_DEFAULT_COMPRESSION, bool gzLib = false ); tools::Long EndCompression(); diff --git a/tools/source/zcodec/zcodec.cxx b/tools/source/zcodec/zcodec.cxx index 97a03a463021..80daa1507a19 100644 --- a/tools/source/zcodec/zcodec.cxx +++ b/tools/source/zcodec/zcodec.cxx @@ -36,7 +36,7 @@ #define GZ_COMMENT 0x10 /* bit 4 set: file comment present */ #define GZ_RESERVED 0xE0 /* bits 5..7: reserved */ -const int gz_magic[2] = { 0x1f, 0x8b }; /* gzip magic header */ +constexpr sal_uInt16 GZ_MAGIC_BYTES_LE = 0x8B1F; /* gzip magic bytes, little endian */ ZCodec::ZCodec( size_t nInBufSize, size_t nOutBufSize ) : meState(STATE_INIT) @@ -58,6 +58,16 @@ ZCodec::~ZCodec() delete pStream; } +bool ZCodec::IsZCompressed( SvStream& rIStm ) +{ + sal_uInt64 nCurPos = rIStm.Tell(); + rIStm.Seek( 0 ); + sal_uInt16 nFirstTwoBytes = 0; + rIStm.ReadUInt16( nFirstTwoBytes ); + rIStm.Seek( nCurPos ); + return nFirstTwoBytes == GZ_MAGIC_BYTES_LE; +} + void ZCodec::BeginCompression( int nCompressLevel, bool gzLib ) { assert(meState == STATE_INIT); @@ -272,12 +282,11 @@ void ZCodec::InitDecompress(SvStream & inStream) if ( mbStatus && mbGzLib ) { sal_uInt8 j, nMethod, nFlags; - for (int i : gz_magic) // gz - magic number - { - inStream.ReadUChar( j ); - if ( j != i ) - mbStatus = false; - } + sal_uInt16 nFirstTwoBytes; + inStream.Seek( 0 ); + inStream.ReadUInt16( nFirstTwoBytes ); + if ( nFirstTwoBytes != GZ_MAGIC_BYTES_LE ) + mbStatus = false; inStream.ReadUChar( nMethod ); inStream.ReadUChar( nFlags ); if ( nMethod != Z_DEFLATED ) diff --git a/vcl/inc/graphic/GraphicFormatDetector.hxx b/vcl/inc/graphic/GraphicFormatDetector.hxx index 34a8b16a2c5d..dc1bbf0b3e08 100644 --- a/vcl/inc/graphic/GraphicFormatDetector.hxx +++ b/vcl/inc/graphic/GraphicFormatDetector.hxx @@ -78,6 +78,19 @@ public: bool checkMOV(); bool checkPDF(); bool checkWEBP(); + +private: + /** + * @brief Checks whether mrStream needs to be uncompressed and returns a pointer to the + * to aUncompressedBuffer or a pointer to maFirstBytes if it doesn't need to be uncompressed + * + * @param aUncompressedBuffer the buffer to hold the uncompressed data + * @param nSize the amount of bytes to uncompress + * @param nRetSize the amount of bytes actually uncompressed + * @return sal_uInt8* a pointer to maFirstBytes or aUncompressed buffer + */ + sal_uInt8* checkAndUncompressBuffer(sal_uInt8* aUncompressedBuffer, sal_uInt32 nSize, + sal_uInt64& nDecompressedSize); }; } diff --git a/vcl/qa/cppunit/GraphicFormatDetectorTest.cxx b/vcl/qa/cppunit/GraphicFormatDetectorTest.cxx index 1061b12fd2df..e142c94ab1be 100644 --- a/vcl/qa/cppunit/GraphicFormatDetectorTest.cxx +++ b/vcl/qa/cppunit/GraphicFormatDetectorTest.cxx @@ -35,6 +35,7 @@ class GraphicFormatDetectorTest : public test::BootstrapFixtureBase void testDetectMET(); void testDetectBMP(); void testDetectWMF(); + void testDetectWMZ(); void testDetectPCX(); void testDetectJPG(); void testDetectPNG(); @@ -49,6 +50,8 @@ class GraphicFormatDetectorTest : public test::BootstrapFixtureBase void testDetectPDF(); void testDetectEPS(); void testDetectWEBP(); + void testDetectEMF(); + void testDetectEMZ(); void testMatchArray(); void testCheckArrayForMatchingStrings(); @@ -56,6 +59,7 @@ class GraphicFormatDetectorTest : public test::BootstrapFixtureBase CPPUNIT_TEST(testDetectMET); CPPUNIT_TEST(testDetectBMP); CPPUNIT_TEST(testDetectWMF); + CPPUNIT_TEST(testDetectWMZ); CPPUNIT_TEST(testDetectPCX); CPPUNIT_TEST(testDetectJPG); CPPUNIT_TEST(testDetectPNG); @@ -70,6 +74,8 @@ class GraphicFormatDetectorTest : public test::BootstrapFixtureBase CPPUNIT_TEST(testDetectPDF); CPPUNIT_TEST(testDetectEPS); CPPUNIT_TEST(testDetectWEBP); + CPPUNIT_TEST(testDetectEMF); + CPPUNIT_TEST(testDetectEMZ); CPPUNIT_TEST(testMatchArray); CPPUNIT_TEST(testCheckArrayForMatchingStrings); CPPUNIT_TEST_SUITE_END(); @@ -120,6 +126,21 @@ void GraphicFormatDetectorTest::testDetectWMF() CPPUNIT_ASSERT_EQUAL(OUString("WMF"), rFormatExtension); } +void GraphicFormatDetectorTest::testDetectWMZ() +{ + SvFileStream aFileStream(getFullUrl(u"TypeDetectionExample.wmz"), StreamMode::READ); + vcl::GraphicFormatDetector aDetector(aFileStream, "WMF"); + + CPPUNIT_ASSERT(aDetector.detect()); + CPPUNIT_ASSERT(aDetector.checkWMForEMF()); + + aFileStream.Seek(aDetector.mnStreamPosition); + + OUString rFormatExtension; + CPPUNIT_ASSERT(vcl::peekGraphicFormat(aFileStream, rFormatExtension, false)); + CPPUNIT_ASSERT_EQUAL(OUString("WMF"), rFormatExtension); +} + void GraphicFormatDetectorTest::testDetectPCX() { SvFileStream aFileStream(getFullUrl(u"TypeDetectionExample.pcx"), StreamMode::READ); @@ -330,6 +351,36 @@ void GraphicFormatDetectorTest::testDetectWEBP() CPPUNIT_ASSERT_EQUAL(OUString("WEBP"), rFormatExtension); } +void GraphicFormatDetectorTest::testDetectEMF() +{ + SvFileStream aFileStream(getFullUrl(u"TypeDetectionExample.emf"), StreamMode::READ); + vcl::GraphicFormatDetector aDetector(aFileStream, "EMF"); + + CPPUNIT_ASSERT(aDetector.detect()); + CPPUNIT_ASSERT(aDetector.checkWMForEMF()); + + aFileStream.Seek(aDetector.mnStreamPosition); + + OUString rFormatExtension; + CPPUNIT_ASSERT(vcl::peekGraphicFormat(aFileStream, rFormatExtension, false)); + CPPUNIT_ASSERT_EQUAL(OUString("EMF"), rFormatExtension); +} + +void GraphicFormatDetectorTest::testDetectEMZ() +{ + SvFileStream aFileStream(getFullUrl(u"TypeDetectionExample.emz"), StreamMode::READ); + vcl::GraphicFormatDetector aDetector(aFileStream, "EMF"); + + CPPUNIT_ASSERT(aDetector.detect()); + CPPUNIT_ASSERT(aDetector.checkWMForEMF()); + + aFileStream.Seek(aDetector.mnStreamPosition); + + OUString rFormatExtension; + CPPUNIT_ASSERT(vcl::peekGraphicFormat(aFileStream, rFormatExtension, false)); + CPPUNIT_ASSERT_EQUAL(OUString("EMF"), rFormatExtension); +} + void GraphicFormatDetectorTest::testMatchArray() { std::string aString("<?xml version=\"1.0\" standalone=\"no\"?>\n" diff --git a/vcl/qa/cppunit/data/TypeDetectionExample.emf b/vcl/qa/cppunit/data/TypeDetectionExample.emf new file mode 100644 index 000000000000..571a25c81bbf Binary files /dev/null and b/vcl/qa/cppunit/data/TypeDetectionExample.emf differ diff --git a/vcl/qa/cppunit/data/TypeDetectionExample.emz b/vcl/qa/cppunit/data/TypeDetectionExample.emz new file mode 100644 index 000000000000..dd3b3b2f1fa3 Binary files /dev/null and b/vcl/qa/cppunit/data/TypeDetectionExample.emz differ diff --git a/vcl/qa/cppunit/data/TypeDetectionExample.wmz b/vcl/qa/cppunit/data/TypeDetectionExample.wmz new file mode 100644 index 000000000000..2435f20baf57 Binary files /dev/null and b/vcl/qa/cppunit/data/TypeDetectionExample.wmz differ diff --git a/vcl/source/filter/GraphicFormatDetector.cxx b/vcl/source/filter/GraphicFormatDetector.cxx index 2dddcfa0f9ae..6ef3d3015817 100644 --- a/vcl/source/filter/GraphicFormatDetector.cxx +++ b/vcl/source/filter/GraphicFormatDetector.cxx @@ -26,6 +26,9 @@ #include <tools/solar.h> #include <tools/zcodec.hxx> +constexpr sal_uInt32 SVG_CHECK_SIZE = 2048; +constexpr sal_uInt32 WMF_EMF_CHECK_SIZE = 44; + namespace vcl { bool peekGraphicFormat(SvStream& rStream, OUString& rFormatExtension, bool bTest) @@ -66,7 +69,8 @@ bool peekGraphicFormat(SvStream& rStream, OUString& rFormatExtension, bool bTest } } - if (!bTest || rFormatExtension.startsWith("WMF") || rFormatExtension.startsWith("EMF")) + if (!bTest || rFormatExtension.startsWith("WMF") || rFormatExtension.startsWith("EMF") + || rFormatExtension.startsWith("WMZ") || rFormatExtension.startsWith("EMZ")) { bSomethingTested = true; if (aDetector.checkWMForEMF()) @@ -450,13 +454,19 @@ bool GraphicFormatDetector::checkBMP() bool GraphicFormatDetector::checkWMForEMF() { + sal_uInt64 nCheckSize = std::min<sal_uInt64>(mnStreamLength, 256); + sal_uInt8 sExtendedOrDecompressedFirstBytes[WMF_EMF_CHECK_SIZE]; + sal_uInt64 nDecompressedSize = nCheckSize; + // check if it is gzipped -> wmz/emz + sal_uInt8* pCheckArray = checkAndUncompressBuffer(sExtendedOrDecompressedFirstBytes, + WMF_EMF_CHECK_SIZE, nDecompressedSize); if (mnFirstLong == 0xd7cdc69a || mnFirstLong == 0x01000900) { msDetectedFormat = "WMF"; return true; } - else if (mnFirstLong == 0x01000000 && maFirstBytes[40] == 0x20 && maFirstBytes[41] == 0x45 - && maFirstBytes[42] == 0x4d && maFirstBytes[43] == 0x46) + else if (mnFirstLong == 0x01000000 && pCheckArray[40] == 0x20 && pCheckArray[41] == 0x45 + && pCheckArray[42] == 0x4d && pCheckArray[43] == 0x46) { msDetectedFormat = "EMF"; return true; @@ -696,34 +706,16 @@ bool GraphicFormatDetector::checkXBM() bool GraphicFormatDetector::checkSVG() { - sal_uInt8* pCheckArray = maFirstBytes.data(); sal_uInt64 nCheckSize = std::min<sal_uInt64>(mnStreamLength, 256); - - sal_uInt8 sExtendedOrDecompressedFirstBytes[2048]; + sal_uInt8 sExtendedOrDecompressedFirstBytes[SVG_CHECK_SIZE]; sal_uInt64 nDecompressedSize = nCheckSize; - - bool bIsGZip(false); - // check if it is gzipped -> svgz - if (maFirstBytes[0] == 0x1F && maFirstBytes[1] == 0x8B) - { - ZCodec aCodec; - mrStream.Seek(mnStreamPosition); - aCodec.BeginCompression(ZCODEC_DEFAULT_COMPRESSION, /*gzLib*/ true); - auto nDecompressedOut = aCodec.Read(mrStream, sExtendedOrDecompressedFirstBytes, 2048); - // ZCodec::Decompress returns -1 on failure - nDecompressedSize = nDecompressedOut < 0 ? 0 : nDecompressedOut; - nCheckSize = std::min<sal_uInt64>(nDecompressedSize, 256); - aCodec.EndCompression(); - pCheckArray = sExtendedOrDecompressedFirstBytes; - - bIsGZip = true; - } - + sal_uInt8* pCheckArray = checkAndUncompressBuffer(sExtendedOrDecompressedFirstBytes, + SVG_CHECK_SIZE, nDecompressedSize); + nCheckSize = std::min<sal_uInt64>(nDecompressedSize, 256); bool bIsSvg(false); - + bool bIsGZip = (nDecompressedSize > 0); const char* pCheckArrayAsCharArray = reinterpret_cast<char*>(pCheckArray); - // check for XML // #119176# SVG files which have no xml header at all have shown up this is optional // check for "xml" then "version" then "DOCTYPE" and "svg" tags @@ -838,6 +830,30 @@ bool GraphicFormatDetector::checkWEBP() return false; } +sal_uInt8* GraphicFormatDetector::checkAndUncompressBuffer(sal_uInt8* aUncompressedBuffer, + sal_uInt32 nSize, sal_uInt64& nRetSize) +{ + if (ZCodec::IsZCompressed(mrStream)) + { + ZCodec aCodec; + mrStream.Seek(mnStreamPosition); + aCodec.BeginCompression(ZCODEC_DEFAULT_COMPRESSION, /*gzLib*/ true); + auto nDecompressedOut = aCodec.Read(mrStream, aUncompressedBuffer, nSize); + // ZCodec::Decompress returns -1 on failure + nRetSize = nDecompressedOut < 0 ? 0 : nDecompressedOut; + aCodec.EndCompression(); + // Recalculate first/second long + for (int i = 0; i < 4; ++i) + { + mnFirstLong = (mnFirstLong << 8) | sal_uInt32(aUncompressedBuffer[i]); + mnSecondLong = (mnSecondLong << 8) | sal_uInt32(aUncompressedBuffer[i + 4]); + } + return aUncompressedBuffer; + } + nRetSize = 0; + return maFirstBytes.data(); +} + } // vcl namespace /* vim:set shiftwidth=4 softtabstop=4 expandtab: */ diff --git a/vcl/source/filter/graphicfilter.cxx b/vcl/source/filter/graphicfilter.cxx index 9bc7eea56566..68a2418fed58 100644 --- a/vcl/source/filter/graphicfilter.cxx +++ b/vcl/source/filter/graphicfilter.cxx @@ -891,10 +891,29 @@ Graphic GraphicFilter::ImportUnloadedGraphic(SvStream& rIStream, sal_uInt64 size { nGraphicContentSize = nStreamLength; pGraphicContent.reset(new sal_uInt8[nGraphicContentSize]); - rIStream.Seek(nStreamBegin); - rIStream.ReadBytes(pGraphicContent.get(), nStreamLength); + if (ZCodec::IsZCompressed(rIStream)) + { + ZCodec aCodec; + SvMemoryStream aMemStream; + tools::Long nMemoryLength; + aCodec.BeginCompression(ZCODEC_DEFAULT_COMPRESSION, /*gzLib*/true); + nMemoryLength = aCodec.Decompress(rIStream, aMemStream); + aCodec.EndCompression(); + + if (!rIStream.GetError() && nMemoryLength >= 0) + { + nGraphicContentSize = nMemoryLength; + pGraphicContent.reset(new sal_uInt8[nGraphicContentSize]); + aMemStream.Seek(STREAM_SEEK_TO_BEGIN); + aMemStream.ReadBytes(pGraphicContent.get(), nGraphicContentSize); + } + } + else + { + rIStream.ReadBytes(pGraphicContent.get(), nStreamLength); + } if (!rIStream.GetError()) { eLinkType = GfxLinkType::NativeWmf; @@ -1148,15 +1167,22 @@ ErrCode GraphicFilter::readWMF_EMF(SvStream & rStream, Graphic & rGraphic, GfxLi // use new UNO API service, do not directly import but create a // Graphic that contains the original data and decomposes to // primitives on demand - + sal_uInt32 nStreamLength(rStream.remainingSize()); + SvStream* aNewStream = &rStream; ErrCode aReturnCode = ERRCODE_GRFILTER_FILTERERROR; - - const sal_uInt32 nStreamLength(rStream.remainingSize()); + SvMemoryStream aMemStream; + if (ZCodec::IsZCompressed(rStream)) + { + ZCodec aCodec; + aCodec.BeginCompression(ZCODEC_DEFAULT_COMPRESSION, /*gzLib*/true); + nStreamLength = aCodec.Decompress(rStream, aMemStream); + aCodec.EndCompression(); + aNewStream = &aMemStream; + } VectorGraphicDataArray aNewData(nStreamLength); - - rStream.ReadBytes(aNewData.getArray(), nStreamLength); - - if (!rStream.GetError()) + aNewStream->Seek(STREAM_SEEK_TO_BEGIN); + aNewStream->ReadBytes(aNewData.getArray(), nStreamLength); + if (!aNewStream->GetError()) { const VectorGraphicDataType aDataType(eType); BinaryDataContainer aDataContainer(reinterpret_cast<const sal_uInt8*>(aNewData.getConstArray()), aNewData.getLength()); diff --git a/vcl/source/filter/graphicfilter2.cxx b/vcl/source/filter/graphicfilter2.cxx index 5f73d570d9f6..eaef61b1d1e1 100644 --- a/vcl/source/filter/graphicfilter2.cxx +++ b/vcl/source/filter/graphicfilter2.cxx @@ -1079,59 +1079,19 @@ bool GraphicDescriptor::ImpDetectSVM( SvStream& rStm, bool bExtendedInfo ) bool GraphicDescriptor::ImpDetectWMF( SvStream&, bool ) { - bool bRet = aPathExt.startsWith( "wmf" ); + bool bRet = aPathExt.startsWith( "wmf" ) || aPathExt.startsWith( "wmz" ); if (bRet) nFormat = GraphicFileFormat::WMF; return bRet; } -bool GraphicDescriptor::ImpDetectEMF( SvStream& rStm, bool bExtendedInfo ) +bool GraphicDescriptor::ImpDetectEMF( SvStream&, bool ) { - sal_uInt32 nRecordType = 0; - bool bRet = false; - - sal_Int32 nStmPos = rStm.Tell(); - rStm.SetEndian( SvStreamEndian::LITTLE ); - rStm.ReadUInt32( nRecordType ); - - if ( nRecordType == 0x00000001 ) - { - sal_uInt32 nHeaderSize = 0; - sal_Int32 nBoundLeft = 0, nBoundTop = 0, nBoundRight = 0, nBoundBottom = 0; - sal_Int32 nFrameLeft = 0, nFrameTop = 0, nFrameRight = 0, nFrameBottom = 0; - sal_uInt32 nSignature = 0; - - rStm.ReadUInt32( nHeaderSize ); - rStm.ReadInt32( nBoundLeft ); - rStm.ReadInt32( nBoundTop ); - rStm.ReadInt32( nBoundRight ); - rStm.ReadInt32( nBoundBottom ); - rStm.ReadInt32( nFrameLeft ); - rStm.ReadInt32( nFrameTop ); - rStm.ReadInt32( nFrameRight ); - rStm.ReadInt32( nFrameBottom ); - rStm.ReadUInt32( nSignature ); - - if ( nSignature == 0x464d4520 ) - { - nFormat = GraphicFileFormat::EMF; - bRet = true; - - if ( bExtendedInfo ) - { - // size in pixels - aPixSize.setWidth( nBoundRight - nBoundLeft + 1 ); - aPixSize.setHeight( nBoundBottom - nBoundTop + 1 ); - - // size in 0.01mm units - aLogSize.setWidth( nFrameRight - nFrameLeft + 1 ); - aLogSize.setHeight( nFrameBottom - nFrameTop + 1 ); - } - } - } + bool bRet = aPathExt.startsWith( "emf" ) || aPathExt.startsWith( "emz" ); + if (bRet) + nFormat = GraphicFileFormat::EMF; - rStm.Seek( nStmPos ); return bRet; }
