external/redland: Avoid UBSan nullptr-with-nonzero-offset

...(new with Clang 10 trunk), as seen during CppunitTest_sw_ooxmlexport:

> raptor_rfc2396.c:389:23: runtime error: applying non-zero offset 2 to null pointer
>  #0 in raptor_uri_normalize_path at workdir/UnpackedTarball/raptor/src/raptor_rfc2396.c:389:23
>  #1 in raptor_uri_resolve_uri_reference at workdir/UnpackedTarball/raptor/src/raptor_rfc2396.c:617:21
>  #2 in raptor_new_uri_relative_to_base_counted at workdir/UnpackedTarball/raptor/src/raptor_uri.c:293:19
>  #3 in raptor_new_uri_relative_to_base at workdir/UnpackedTarball/raptor/src/raptor_uri.c:319:10
>  #4 in raptor_rdfxml_end_element_grammar at workdir/UnpackedTarball/raptor/src/raptor_rdfxml.c:2613:32
>  #5 in raptor_rdfxml_end_element_handler at workdir/UnpackedTarball/raptor/src/raptor_rdfxml.c:850:5
>  #6 in raptor_sax2_end_element at workdir/UnpackedTarball/raptor/src/raptor_sax2.c:867:7
>  #7 in xmlParseTryOrFinish at workdir/UnpackedTarball/libxml2/parser.c:11386:8
>  #8 in xmlParseChunk__internal_alias at workdir/UnpackedTarball/libxml2/parser.c:12244:13
>  #9 in raptor_sax2_parse_chunk at workdir/UnpackedTarball/raptor/src/raptor_sax2.c:534:10
>  #10 in raptor_rdfxml_parse_chunk at workdir/UnpackedTarball/raptor/src/raptor_rdfxml.c:1169:8
>  #11 in raptor_parser_parse_chunk at workdir/UnpackedTarball/raptor/src/raptor_parse.c:482:10
>  #12 in librdf_parser_raptor_parse_as_stream_common at <null> (instdir/program/librdf-lo.so.0 +0x11ee39)
>  #13 in librdf_parser_raptor_parse_counted_string_as_stream at <null> (instdir/program/librdf-lo.so.0 +0x117ca4)
>  #14 in librdf_parser_parse_counted_string_as_stream at <null> (instdir/program/librdf-lo.so.0 +0x111967)
>  #15 in (anonymous namespace)::librdf_Repository::importGraph(short, com::sun::star::uno::Reference<com::sun::star::io::XInputStream> const&, com::sun::star::uno::Reference<com::sun::star::rdf::XURI> const&, com::sun::star::uno::Reference<com::sun::star::rdf::XURI> const&) at unoxml/source/rdf/librdf_repository.cxx:1048:9
>  #17 in sfx2::readStream(sfx2::DocumentMetadataAccess_Impl&, com::sun::star::uno::Reference<com::sun::star::embed::XStorage> const&, rtl::OUString const&, rtl::OUString const&) at sfx2/source/doc/DocumentMetadataAccess.cxx:606:36
>  #18 in sfx2::initLoading(sfx2::DocumentMetadataAccess_Impl&, com::sun::star::uno::Reference<com::sun::star::embed::XStorage> const&, com::sun::star::uno::Reference<com::sun::star::rdf::XURI> const&, com::sun::star::uno::Reference<com::sun::star::task::XInteractionHandler> const&) at sfx2/source/doc/DocumentMetadataAccess.cxx:763:9
>  #19 in sfx2::DocumentMetadataAccess::loadMetadataFromStorage(com::sun::star::uno::Reference<com::sun::star::embed::XStorage> const&, com::sun::star::uno::Reference<com::sun::star::rdf::XURI> const&, com::sun::star::uno::Reference<com::sun::star::task::XInteractionHandler> const&) at sfx2/source/doc/DocumentMetadataAccess.cxx:1126:5
>  #20 in SfxBaseModel::loadMetadataFromStorage(com::sun::star::uno::Reference<com::sun::star::embed::XStorage> const&, com::sun::star::uno::Reference<com::sun::star::rdf::XURI> const&, com::sun::star::uno::Reference<com::sun::star::task::XInteractionHandler> const&) at sfx2/source/doc/sfxbasemodel.cxx:4411:15
>  #21 in XMLReader::Read(SwDoc&, rtl::OUString const&, SwPaM&, rtl::OUString const&) at sw/source/filter/xml/swxml.cxx:810:19
>  #22 in SwReader::Read(Reader const&) at sw/source/filter/basflt/shellio.cxx:188:22
>  #23 in SwDocShell::Load(SfxMedium&) at sw/source/uibase/app/docshini.cxx:546:37
>  #24 in SfxObjectShell::LoadOwnFormat(SfxMedium&) at sfx2/source/doc/objstor.cxx:3040:20
>  #25 in SfxObjectShell::DoLoad(SfxMedium*) at sfx2/source/doc/objstor.cxx:696:40
>  #26 in SfxBaseModel::load(com::sun::star::uno::Sequence<com::sun::star::beans::PropertyValue> const&) at sfx2/source/doc/sfxbasemodel.cxx:1851:36
>  #27 in (anonymous namespace)::SfxFrameLoader_Impl::load(com::sun::star::uno::Sequence<com::sun::star::beans::PropertyValue> const&, com::sun::star::uno::Reference<com::sun::star::frame::XFrame> const&) at sfx2/source/view/frmload.cxx:691:28
>  #28 in framework::LoadEnv::impl_loadContent() at framework/source/loadenv/loadenv.cxx:1157:37
>  #29 in framework::LoadEnv::startLoading() at framework/source/loadenv/loadenv.cxx:390:20
>  #30 in framework::LoadEnv::loadComponentFromURL(com::sun::star::uno::Reference<com::sun::star::frame::XComponentLoader> const&, com::sun::star::uno::Reference<com::sun::star::uno::XComponentContext> const&, rtl::OUString const&, rtl::OUString const&, int, com::sun::star::uno::Sequence<com::sun::star::beans::PropertyValue> const&) at framework/source/loadenv/loadenv.cxx:171:14
>  #31 in framework::Desktop::loadComponentFromURL(rtl::OUString const&, rtl::OUString const&, int, com::sun::star::uno::Sequence<com::sun::star::beans::PropertyValue> const&) at framework/source/services/desktop.cxx:621:12
>  #32 in non-virtual thunk to framework::Desktop::loadComponentFromURL(rtl::OUString const&, rtl::OUString const&, int, com::sun::star::uno::Sequence<com::sun::star::beans::PropertyValue> const&) at framework/source/services/desktop.cxx
>  #33 in unotest::MacrosTest::loadFromDesktop(rtl::OUString const&, rtl::OUString const&, com::sun::star::uno::Sequence<com::sun::star::beans::PropertyValue> const&) at unotest/source/cpp/macros_test.cxx:48:62
>  #34 in SwModelTestBase::loadURL(rtl::OUString const&, char const*, char const*) at sw/qa/extras/inc/swmodeltestbase.hxx:765:23
>  #35 in SwModelTestBase::load(rtl::OUString const&, char const*, char const*) at sw/qa/extras/inc/swmodeltestbase.hxx:720:16
>  #36 in SwModelTestBase::executeImportExportImportTest(char const*, char const*) at sw/qa/extras/inc/swmodeltestbase.hxx:290:9
>  #37 in testTdf118393::Import_Export_Import() at sw/qa/extras/ooxmlexport/ooxmlexport.cxx:84:1

Presumably, `cur` can legitimately be null there and the `s == (cur+2)` check
was intended to always be false when `cur` is null?

Change-Id: I0e3b762d5868933e586eb8f2255148f88a54e908
Reviewed-on: https://gerrit.libreoffice.org/81318
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

0 files changed, 0 insertions, 0 deletions