CID#736013 unlikely invalid iterator use

Change-Id: I78928d4eee28adbb06b4087c51a4b384ca4e43f8

dbaccess/source/ui/misc/WNameMatch.cxx

@@ -161,7 +161,13 @@ sal_Bool OWizNameMatching::LeavePage()
             m_pParent->m_vColumnPos[nPos].first = ++nParamPos;
             m_pParent->m_vColumnPos[nPos].second = ::std::distance(pDestColumns->begin(),aDestIter) + 1;
             sal_Bool bNotConvert = sal_True;
-            TOTypeInfoSP pTypeInfo = m_pParent->convertType((*aDestIter)->second->getSpecialTypeInfo(),bNotConvert);
+
+            TOTypeInfoSP pTypeInfo;
+
+            assert(aDestIter != aDestEnd);
+            if (aDestIter != aDestEnd)
+                pTypeInfo = m_pParent->convertType((*aDestIter)->second->getSpecialTypeInfo(),bNotConvert);
+
             sal_Int32 nType = ::com::sun::star::sdbc::DataType::VARCHAR;
             if ( pTypeInfo.get() )
                 nType = pTypeInfo->nType;