check start dec

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

diff --git a/zcoord/zcoord.rs b/zcoord/zcoord.rs
index 0acdd07f80a89ba53409eaecacea72544fbe3a8d..ad88c882f7693e54dd8d4c36ab108a54cb2a83a2 100644 (file)
--- a/zcoord/zcoord.rs
+++ b/zcoord/zcoord.rs
@@ -515,6 +515,8 @@ mod test {
     assert_eq!(format!("{}", &start), "g000000000");
     start.clone_mut()
       .tinc("g001000000");
+    start.clone_mut()
+      .tdec("fvvv000000");
 
     mk("000000000a")
       .tinc("000100000a")