Index: filter/source/msfilter/escherex.cxx
===================================================================
--- filter/source/msfilter/escherex.cxx	(revision 1349092)
+++ filter/source/msfilter/escherex.cxx	(working copy)
@@ -2032,8 +2032,12 @@
 	{
 		case com::sun::star::drawing::EnhancedCustomShapeParameterType::EQUATION :
 		{
-			nValue = (sal_uInt16)rEquationOrder[ nValue ];
-			nValue |= (sal_uInt32)0x80000000;
+			OSL_ASSERT(nValue < rEquationOrder.size());
+			if ( nValue < rEquationOrder.size() )
+			{
+				nValue = (sal_uInt16)rEquationOrder[ nValue ];
+				nValue |= (sal_uInt32)0x80000000;
+			}
 		}
 		break;
 		case com::sun::star::drawing::EnhancedCustomShapeParameterType::NORMAL :