isl_tab_basic_set_non_neg_lexmin: handle NULL input

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

diff --git a/isl_tab_pip.c b/isl_tab_pip.c
index 8885360..8d16d5c 100644 (file)
--- a/isl_tab_pip.c
+++ b/isl_tab_pip.c
@@ -5117,6 +5117,9 @@ __isl_give isl_vec *isl_tab_basic_set_non_neg_lexmin(
        isl_ctx *ctx = isl_basic_set_get_ctx(bset);
        isl_vec *sol;
 
+       if (!bset)
+               return NULL;
+
        tab = tab_for_lexmin(bset, NULL, 0, 0);
        if (!tab)
                goto error;