...as found by UBSan in CppunitTest_sw_filters_test (see below); note the TODOs
how best to report the errors up the call stack.

> Testing file:///.../sw/qa/core/data/ww6/pass/crash-3.doc:
> sw/source/filter/ww8/ww8scan.cxx:5240:63: runtime error: signed integer overflow: 1766665948 + 1768712052 cannot be represented in type 'int'
>  WW8Fib::GetBaseCp(ManTypes) const sw/source/filter/ww8/ww8scan.cxx:5240:63
>  SwWW8ImplReader::Read_GrafLayer(long) sw/source/filter/ww8/ww8graf.cxx:2393:18
>  SwWW8ImplReader::ReadChar(long, long) sw/source/filter/ww8/ww8par.cxx:3630:17
>  SwWW8ImplReader::ReadChars(int&, int, long, long) sw/source/filter/ww8/ww8par.cxx:3432:27
>  SwWW8ImplReader::ReadText(int, int, ManTypes) sw/source/filter/ww8/ww8par.cxx:3970:22
>  SwWW8ImplReader::CoreLoad(WW8Glossary*, SwPosition const&) sw/source/filter/ww8/ww8par.cxx:5169:9
>  SwWW8ImplReader::LoadThroughDecryption(SwPaM&, WW8Glossary*) sw/source/filter/ww8/ww8par.cxx:5767:19
>  SwWW8ImplReader::LoadDoc(SwPaM&, WW8Glossary*) sw/source/filter/ww8/ww8par.cxx:6039:19
>  WW8Reader::Read(SwDoc&, rtl::OUString const&, SwPaM&, rtl::OUString const&) sw/source/filter/ww8/ww8par.cxx:6157:20
>  SwReader::Read(Reader const&) sw/source/filter/basflt/shellio.cxx:175:18
>  SwDocShell::ConvertFrom(SfxMedium&) sw/source/uibase/app/docsh.cxx:258:22
>  SfxObjectShell::DoLoad(SfxMedium*) sfx2/source/doc/objstor.cxx:790:23
>  SwFiltersTest::filter(rtl::OUString const&, rtl::OUString const&, rtl::OUString const&, SfxFilterFlags, SotClipboardFormatId, unsigned int, bool) sw/qa/core/filters-test.cxx:112:20
>  SwFiltersTest::load(rtl::OUString const&, rtl::OUString const&, rtl::OUString const&, SfxFilterFlags, SotClipboardFormatId, unsigned int) sw/qa/core/filters-test.cxx:71:12
>  test::FiltersTest::recursiveScan(test::filterStatus, rtl::OUString const&, rtl::OUString const&, rtl::OUString const&, SfxFilterFlags, SotClipboardFormatId, unsigned int, bool) unotest/source/cpp/filters-test.cxx:129:20
>  test::FiltersTest::testDir(rtl::OUString const&, rtl::OUString const&, rtl::OUString const&, SfxFilterFlags, SotClipboardFormatId, unsigned int, bool) unotest/source/cpp/filters-test.cxx:154:5
>  SwFiltersTest::testCVEs() sw/qa/core/filters-test.cxx:154:5

Change-Id: I0b14f5c1e025565eb131e64590b7d5ff0135e767
Reviewed-on: https://gerrit.libreoffice.org/17965Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>
(cherry picked from commit d281b460)
Reviewed-on: https://gerrit.libreoffice.org/17969Reviewed-by: David Tardon <dtardon@redhat.com>
Tested-by: David Tardon <dtardon@redhat.com>