cdirect: check for infinite values (#640)

Closes #639

Author: jschueller

src/algs/cdirect/cdirect.c

@@ -200,6 +200,10 @@ static nlopt_result divide_rect(double *rdiv, params *p)
 		    rnew[3 + isort[i]] += w[isort[i]] * (2*k-1);
 		    rnew[1] = fv[2*isort[i]+k];
 		    rnew[2] = p->age++;
+				if (!isfinite(rnew[1])) {
+					free(rnew);
+					return NLOPT_FAILURE;
+				}
 		    if (!nlopt_rb_tree_insert(&p->rtree, rnew)) {
 			 free(rnew);
 			 return NLOPT_OUT_OF_MEMORY;
@@ -233,6 +237,10 @@ static nlopt_result divide_rect(double *rdiv, params *p)
 	       rnew[3 + i] += w[i] * (2*k-1);
 	       FUNCTION_EVAL(rnew[1], rnew + 3, p, rnew);
 	       rnew[2] = p->age++;
+				 if (!isfinite(rnew[1])) {
+					free(rnew);
+					return NLOPT_FAILURE;
+				}
 	       if (!nlopt_rb_tree_insert(&p->rtree, rnew)) {
 		    free(rnew);
 		    return NLOPT_OUT_OF_MEMORY;