ofz#4946 keep nPos within bounds

Change-Id: Ib5dc37b489b7b2101cf852a46f48fff1b7447a30
Reviewed-on: https://gerrit.libreoffice.org/47378Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Stahl <mstahl@redhat.com>

lotuswordpro/source/filter/lwpsilverbullet.hxx

@@ -153,7 +153,9 @@ inline const OUString& LwpSilverBullet::GetBulletStyleName() const
 }
 inline bool LwpSilverBullet::IsLesserLevel(sal_uInt16 nPos)
 {
-    return ((m_pResetPositionFlags[nPos] & LESSERLEVEL) != 0);
+    if (nPos < SAL_N_ELEMENTS(m_pResetPositionFlags))
+        return ((m_pResetPositionFlags[nPos] & LESSERLEVEL) != 0);
+    return false;
 }
 
 #endif