Handle sequence structs in length.

* lib.c (length): In COBJ case, handle
structures which have a car slot.

1 files changed, 2 insertions, 0 deletions

diff --git a/lib.c b/lib.c
index 29d11ef9..89782b25 100644
--- a/lib.c
+++ b/lib.c
@@ -8048,6 +8048,8 @@ val length(val seq)
   case COBJ:
     if (seq->co.cls == hash_s)
       return hash_count(seq);
+    if (structp(seq) && maybe_slot(seq, car_s))
+      return length_list(nullify(seq));
     /* fallthrough */
   default:
     type_mismatch(lit("length: ~s is not a sequence"), seq, nao);