ofz#20447 Null-dereference READ

Change-Id: I76c1c815ab5aaf4548c886a69989fcabe3de5248
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/87802
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>

lotuswordpro/source/filter/lwprowlayout.cxx

@@ -191,7 +191,8 @@ void LwpRowLayout::Read()
 void LwpRowLayout::ConvertRow(rtl::Reference<XFTable> const & pXFTable,sal_uInt8 nStartCol,sal_uInt8 nEndCol)
 {
     LwpTableLayout* pTableLayout = GetParentTableLayout();
-    assert(pTableLayout);
+    if (!pTableLayout)
+        throw std::runtime_error("missing TableLayout");
     LwpTable* pTable = pTableLayout->GetTable();
 
     //calculate the connected cell position