[Libreoffice-commits] core.git: tools/source

[Stephan Bergmann (via logerrit)]

 tools/source/stream/stream.cxx |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

New commits:
commit b25fd58a1ecba62f7967dd118194f5994fcd5c23
Author:     Stephan Bergmann <sbergman at redhat.com>
AuthorDate: Mon Oct 21 15:34:44 2019 +0200
Commit:     Stephan Bergmann <sbergman at redhat.com>
CommitDate: Mon Oct 21 19:18:25 2019 +0200

    -fsanitize=nullptr-with-nonzero-offset
    
    ...(new with Clang 10 trunk), as seen during CppunitTest_emfio_wmf:
    
    > tools/source/stream/stream.cxx:808:32: runtime error: applying non-zero offset 10 to null pointer
    >  #0 in SvStream::SeekRel(long) at tools/source/stream/stream.cxx:808:32
    >  #1 in (anonymous namespace)::ImplReadDIBFileHeader(SvStream&, unsigned long&) at vcl/source/gdi/dibtools.cxx:1085:19
    >  #2 in (anonymous namespace)::ImplReadDIB(Bitmap&, AlphaMask*, SvStream&, bool, bool, bool) at vcl/source/gdi/dibtools.cxx:1656:12
    >  #3 in ReadDIB(Bitmap&, SvStream&, bool, bool) at vcl/source/gdi/dibtools.cxx:1738:12
    >  #4 in emfio::EmfReader::ReadEnhWMF() at emfio/source/reader/emfreader.cxx:1507:33
    >  #5 in emfio::emfreader::XEmfParser::getDecomposition(com::sun::star::uno::Reference<com::sun::star::io::XInputStream> const&, rtl::OUString const&, com::sun::star::uno::Sequence<com::sun::star::beans::PropertyValue> const&) at emfio/source/emfuno/xemfparser.cxx:148:72
    >  #6 in non-virtual thunk to emfio::emfreader::XEmfParser::getDecomposition(com::sun::star::uno::Reference<com::sun::star::io::XInputStream> const&, rtl::OUString const&, com::sun::star::uno::Sequence<com::sun::star::beans::PropertyValue> const&) at emfio/source/emfuno/xemfparser.cxx
    >  #7 in VectorGraphicData::ensureSequenceAndRange() at vcl/source/gdi/vectorgraphicdata.cxx:172:137
    >  #8 in VectorGraphicData::getPrimitive2DSequence() const at vcl/source/gdi/vectorgraphicdata.cxx:279:45
    >  #9 in ImpGraphic::ImplGetGDIMetaFile() const at vcl/source/gdi/impgraph.cxx:844:110
    >  #10 in Graphic::GetGDIMetaFile() const at vcl/source/gdi/graph.cxx:365:26
    >  #11 in ReadWindowMetafile(SvStream&, GDIMetaFile&) at vcl/source/filter/wmf/wmf.cxx:62:25
    >  #12 in WmfTest::testEmfProblem() at emfio/qa/cppunit/wmf/wmfimporttest.cxx:116:5
    
    An invariant of SvStream appears to be that m_pRWBuf can be null and that
    m_pBufPos is null iff m_pRWBuf is null.  So don't update m_pBufPos here when
    m_pRWBuf is null.  (And assert the assumed invariant.)
    
    Change-Id: Iad2eb2723394f5564d43dfa8a3a1a8b8de79158d
    Reviewed-on: https://gerrit.libreoffice.org/81237
    Tested-by: Jenkins
    Reviewed-by: Stephan Bergmann <sbergman at redhat.com>

diff --git a/tools/source/stream/stream.cxx b/tools/source/stream/stream.cxx
index 713d36504b6f..c10dad0457fa 100644
--- a/tools/source/stream/stream.cxx
+++ b/tools/source/stream/stream.cxx
@@ -19,6 +19,9 @@
 
 // TODO: Read->RefreshBuffer-> React to changes from m_nBufActualLen
 
+#include <sal/config.h>
+
+#include <cassert>
 #include <cstddef>
 #include <memory>
 
@@ -805,7 +808,11 @@ sal_uInt64 SvStream::SeekRel(sal_Int64 const nPos)
             nActualPos -= nAbsPos;
     }
 
-    m_pBufPos = m_pRWBuf.get() + nActualPos;
+    assert((m_pBufPos != nullptr) == bool(m_pRWBuf));
+    if (m_pRWBuf)
+    {
+        m_pBufPos = m_pRWBuf.get() + nActualPos;
+    }
     return Seek( nActualPos );
 }