isl_space.c: avoid use of "0" as pointer value

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

diff --git a/isl_space.c b/isl_space.c
index 6a6b5f5..c17c96b 100644 (file)
--- a/isl_space.c
+++ b/isl_space.c
@@ -1651,7 +1651,7 @@ __isl_give isl_space *isl_space_zip(__isl_take isl_space *dim)
                        goto error);
 
        if (!dim)
-               return 0;
+               return NULL;
        dom = isl_space_unwrap(isl_space_domain(isl_space_copy(dim)));
        ran = isl_space_unwrap(isl_space_range(dim));
        dom_dom = isl_space_domain(isl_space_copy(dom));