fdo#61309: writerfilter: filter out enormous numbering levels

Change-Id: Iafef1c2ca2ca072bd604946fbe19b6a24e323512

sw/source/core/unocore/unoobj.cxx

@@ -535,6 +535,11 @@ throw (lang::IllegalArgumentException)
                 sal_Int16 nLevel = 0;
                 if (rValue >>= nLevel)
                 {
+                    if (nLevel < 0 || MAXLEVEL <= nLevel)
+                    {
+                        throw lang::IllegalArgumentException(
+                            "invalid NumberingLevel", 0, 0);
+                    }
                     pTxtNd->SetAttrListLevel(nLevel);
                 }
             }

writerfilter/source/dmapper/DomainMapper.cxx

@@ -1540,7 +1540,12 @@ void DomainMapper::sprmWithProps( Sprm& rSprm, PropertyMapPtr rContext, SprmType
     case NS_sprm::LN_PBrcp:
         break;  // sprmPBrcp
     case NS_sprm::LN_PIlvl: // sprmPIlvl
-        //todo: Numbering level will be implemented in the near future (OOo 3.0?)
+            if (nIntValue < 0 || 10 <= nIntValue) // Writer can't do everything
+            {
+                SAL_INFO("writerfilter",
+                        "unsupported numbering level " << nIntValue);
+                break;
+            }
             if( m_pImpl->IsStyleSheetImport() )
             {
                 //style sheets cannot have a numbering rule attached