isl_map_convex_hull: avoid NULL pointer dereference

diff --git a/isl_convex_hull.c b/isl_convex_hull.c
index cf3cfbf..362c378 100644 (file)
--- a/isl_convex_hull.c
+++ b/isl_convex_hull.c
@@ -1901,6 +1901,8 @@ struct isl_basic_map *isl_map_convex_hull(struct isl_map *map)
        }
 
        convex_hull = isl_basic_map_overlying_set(bset, model);
+       if (!convex_hull)
+               return NULL;
 
        ISL_F_SET(convex_hull, ISL_BASIC_MAP_NO_IMPLICIT);
        ISL_F_SET(convex_hull, ISL_BASIC_MAP_ALL_EQUALITIES);