isl_convex_hull.c: add missing assignment

diff --git a/isl_convex_hull.c b/isl_convex_hull.c
index d11daa4..3912cbf 100644 (file)
--- a/isl_convex_hull.c
+++ b/isl_convex_hull.c
@@ -1068,7 +1068,7 @@ static struct isl_basic_set *modulo_lineality(struct isl_set *set,
        isl_mat_free(set->ctx, M);
        isl_basic_set_free(lin);
 
-       isl_mat_drop_rows(set->ctx, Q, Q->n_row - lin_dim, lin_dim);
+       Q = isl_mat_drop_rows(set->ctx, Q, Q->n_row - lin_dim, lin_dim);
 
        U = isl_mat_lin_to_aff(set->ctx, U);
        Q = isl_mat_lin_to_aff(set->ctx, Q);