isl_polytope_scan: improve error handling

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>

diff --git a/polytope_scan.c b/polytope_scan.c
index 41983aa..fbd80ae 100644 (file)
--- a/polytope_scan.c
+++ b/polytope_scan.c
@@ -72,6 +72,9 @@ static struct isl_mat *isl_basic_set_samples(struct isl_basic_set *bset)
        struct isl_mat *T;
        struct isl_mat *samples;
 
+       if (!bset)
+               return NULL;
+
        if (bset->n_eq == 0)
                return isl_basic_set_scan_samples(bset);