jstest: lower: Only do order check for non-bottom targets

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/jstest/jst-lower.rs b/jstest/jst-lower.rs
index 8c61c3d72cb371876a0f91df0cc1f2a14629f2e1..ef494309cb516be031aad174bb4d439a7bd6d466 100644 (file)
--- a/jstest/jst-lower.rs
+++ b/jstest/jst-lower.rs
@@ -80,10 +80,12 @@ impl Test {
         id: VisiblePieceId,
       }
       let mut nbts = self.targets.iter()
-        .map(|&id| {
-          let old_z = &self.pieces[&id].z;
+        .filter_map(|&id| {
+          let p = &self.pieces[&id];
+          if p.bottom() { return None }
+          let old_z = &p.z;
           let new_z = updated.get(&id).unwrap_or(old_z);
-          Nbt { new_z, old_z, id }
+          Some(Nbt { new_z, old_z, id })
         })
         .collect_vec();
       nbts.sort();