zcoord: Add a test for range carry/borrow

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

diff --git a/base/zcoord.rs b/base/zcoord.rs
index 0b3deac5f4bf667faac3a8e037cf0d9663e9a1a6..3f49412601e38b4b7262d3dddf95e4dca2ec5a08 100644 (file)
--- a/base/zcoord.rs
+++ b/base/zcoord.rs
@@ -939,6 +939,16 @@ mod test {
     it.nxt("3333333334_0000000030");
     assert_eq!(it.i.next(), None);
 
+    let x = bf("3333333333_vvvvvvvvo0").clone_mut();
+    let y = bf("3333333334_0000000030").clone_mut();
+    let i = x.range_upto(&y, 4).unwrap();
+    let mut it = It { i, last: x.repack().unwrap() };
+    it.nxt("3333333333_vvvvvvvvq6");
+    it.nxt("3333333333_vvvvvvvvsc");
+    it.nxt("3333333333_vvvvvvvvui");
+    it.nxt("3333333334_000000000o");
+    assert_eq!(it.i.next(), None);
+
     let x = bf("1000000000").clone_mut();
     let y = bf("2000000000").clone_mut();
     let i = x.range_upto(&y, 3).unwrap();