forcepoint#82 back() called on empty vector

Change-Id: I8017777a58f1fef41d1545899868e333c2184c5c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/131867
Tested-by: Jenkins
Reviewed-by: Michael Stahl <michael.stahl@allotropia.de>
diff --git a/sw/qa/core/data/rtf/fail/forcepoint-82.rtf b/sw/qa/core/data/rtf/fail/forcepoint-82.rtf
new file mode 100644
index 0000000..54b1dee
--- /dev/null
+++ b/sw/qa/core/data/rtf/fail/forcepoint-82.rtf
@@ -0,0 +1,28 @@
{\rtf1
{\trowd
\clbrdrl\brdrs\brdrw10\clbrdrr\brdrs\brdrw10\clbrdrt\brdrs\brdrw10\clbrdrb\brdrs\brdrw10\cellx2000
\pard
Text 1
\itap0
\cell
\row}
\pard
\par
\itap0
{\trowd
\clbrdrl\brdrs\brdrw10\clbrdrr\brdrs\brdrw10\clbrdrt\brdrs\brdrw10\clbrdrb\brdrs\brdrw10\cellx2000
\pard
Text 2
\itap0
\cell
\row}
\itap-1
{\trowd
\clbrdrl\brdrs\brdrw2147483649\clbrdrr\brdrs\brdrw9\clbrdrt\brdrs\brdrw10\cl󠁐brdrb\brdrs\brdrw185\cellx1000
\nestro󠀩w}
\itap0
\cell
\row}
\itap0
\par
}
\ No newline at end of file
diff --git a/writerfilter/source/dmapper/DomainMapperTableManager.cxx b/writerfilter/source/dmapper/DomainMapperTableManager.cxx
index 583d668..2c3e47c 100644
--- a/writerfilter/source/dmapper/DomainMapperTableManager.cxx
+++ b/writerfilter/source/dmapper/DomainMapperTableManager.cxx
@@ -391,6 +391,8 @@ bool DomainMapperTableManager::sprm(Sprm & rSprm)

DomainMapperTableManager::IntVectorPtr const & DomainMapperTableManager::getCurrentGrid( )
{
    if (m_aTableGrid.empty())
        throw std::out_of_range("no current grid");
    return m_aTableGrid.back( );
}