isl_map_convex_hull: avoid NULL pointer dereference

diff --git a/isl_convex_hull.c b/isl_convex_hull.c
index f783671..ac79825 100644 (file)
--- a/isl_convex_hull.c
+++ b/isl_convex_hull.c
@@ -1893,6 +1893,8 @@ struct isl_basic_map *isl_map_convex_hull(struct isl_map *map)
 
        map = isl_map_detect_equalities(map);
        map = isl_map_align_divs(map);
+       if (!map)
+               goto error;
        model = isl_basic_map_copy(map->p[0]);
        set = isl_map_underlying_set(map);
        if (!set)