tests: Test wl_array_release

array-test.c did not cover wl_array_release, so add one test that specifically
tests this method.

Signed-off-by: Yong Bakos <ybakos@humanoriented.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
[Pekka: do not overwrite array.data]
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
diff --git a/tests/array-test.c b/tests/array-test.c
index fe53240..fe589f4 100644
--- a/tests/array-test.c
+++ b/tests/array-test.c
@@ -45,6 +45,20 @@
 	}
 }
 
+TEST(array_release)
+{
+	struct wl_array array;
+	void *ptr;
+
+	wl_array_init(&array);
+	ptr = wl_array_add(&array, 1);
+	assert(ptr != NULL);
+	assert(array.data != NULL);
+
+	wl_array_release(&array);
+	assert(array.data == WL_ARRAY_POISON_PTR);
+}
+
 TEST(array_add)
 {
 	struct mydata {