Author: Julia Lawall <Julia.Lawall@lip6.fr> Put NULL test on the result of the previous call instead on one of its arguments. A simplified version of the semantic match that finds this problem is as follows (http://coccinelle.lip6.fr/): // r@ expression *e1; expression *e2; identifier f; statement S1,S2; @@ e1 = f(…,e2,…); ( if (e1 == NULL || …