isl_affine_hull.c: affine_hull_with_cone: avoid NULL pointer dereference

diff --git a/isl_affine_hull.c b/isl_affine_hull.c
index 73a6590..797b4cf 100644 (file)
--- a/isl_affine_hull.c
+++ b/isl_affine_hull.c
@@ -723,8 +723,11 @@ static struct isl_basic_set *affine_hull_with_cone(struct isl_basic_set *bset,
                else
                        isl_mat_free(U);
                hull = isl_basic_set_preimage(hull, Q);
-               isl_vec_free(hull->sample);
-               hull->sample = sample;
+               if (hull) {
+                       isl_vec_free(hull->sample);
+                       hull->sample = sample;
+               } else
+                       isl_vec_free(sample);
        }
 
        isl_basic_set_free(cone);