static const char EMSG_POSSIBLE_ERROR[] ALIGN1 = "Possible syntax error";
static const char EMSG_UNDEF_FUNC[] ALIGN1 = "Call to undefined function";
static const char EMSG_NO_MATH[] ALIGN1 = "Math support is not compiled in";
+static const char EMSG_NEGATIVE_FIELD[] ALIGN1 = "Access to negative field";
static void zero_out_var(var *vp)
{
case XC( OC_FIELD ): {
int i = (int)getvar_i(R.v);
+ if (i < 0)
+ syntax_error(EMSG_NEGATIVE_FIELD);
if (i == 0) {
res = intvar[F0];
} else {