ofz#10045 Null deref

Change-Id: If9c8edd94b02240510325d6c9c0fc7584ba89b5f
Reviewed-on: https://gerrit.libreoffice.org/59571Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

writerfilter/source/dmapper/DomainMapperTableHandler.cxx

@@ -987,8 +987,11 @@ void DomainMapperTableHandler::endTable(unsigned int nestedTableLevel, bool bTab
         {
             xStart = m_aTableRanges[0][0][0];
             uno::Sequence< uno::Sequence< uno::Reference<text::XTextRange> > >& rLastRow = m_aTableRanges[m_aTableRanges.size() - 1];
-            uno::Sequence< uno::Reference<text::XTextRange> >& rLastCell = rLastRow[rLastRow.getLength() - 1];
-            xEnd = rLastCell[1];
+            if (rLastRow.getLength())
+            {
+                uno::Sequence< uno::Reference<text::XTextRange> >& rLastCell = rLastRow[rLastRow.getLength() - 1];
+                xEnd = rLastCell[1];
+            }
         }
         uno::Reference<text::XTextTable> xTable;
         try