zcoord: Test bad ranges

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

diff --git a/base/zcoord.rs b/base/zcoord.rs
index dbf3749167fc90f73767d618388b0a3ba5367b87..c9b77b9e5dcf45294f0255e785eeeccf325a0ac9 100644 (file)
--- a/base/zcoord.rs
+++ b/base/zcoord.rs
@@ -889,6 +889,16 @@ mod test {
     mk("vvvvvvvvvv_vvvvvvvvvv_vvvvv01234")
       .tinc("vvvvvvvvvv_vvvvvvvvvv_vvvvv01234_0000000000_0001000000")
       ;
+
+    assert_eq!( Mutable::some_range(Some(&mk("0200000000")),
+                                    Some(&mk("0100000000")),
+                                    1).unwrap_err(),
+                LogicError::from(RangeImpossible::Backwards) );
+
+    assert_eq!( Mutable::some_range(Some(&mk("0200000000")),
+                                    Some(&mk("0200000000")),
+                                    1).unwrap_err(),
+                LogicError::from(RangeImpossible::Empty) );
   }
 
   #[test]