organize: check the page's own MediaBox values in the walk test

The root's MediaBox and the page's own both have four numbers, so the
length check passed even if the page lost its own value. Compare the
values instead.

crates/organize/src/tests.rs

@@ -2840,7 +2840,8 @@ fn page_walk_skips_repeated_and_cyclic_kids_without_copying_attributes() {
     assert_eq!(attrs.get(b"Rotate").and_then(Object::as_int), Some(90), "Rotate from the root");
     assert_eq!(walk.next().map(|(p, _)| p), Some(second));
     let (_, last) = walk.next().unwrap();
-    assert_eq!(last.get(b"MediaBox").and_then(Object::as_array).map(Vec::len), Some(4), "own MediaBox kept");
+    let media_box = last.get(b"MediaBox").and_then(Object::as_array).map(|m| m.iter().filter_map(Object::as_int).collect::<Vec<_>>());
+    assert_eq!(media_box, Some(vec![0, 0, 500, 500]), "own MediaBox kept over the root's");
     assert!(walk.next().is_none());
     assert_eq!(labels(&doc), ["Page 1", "Page 2", "Page 3"]);
 }