expander: bugfix: fixed params visible to optionals.

* eval.c (expand_params_rec): Add the parameter to the macro-time
environment before processing rest of parameter list. This is
already done for all the symbols of a macro-style
destructuring; just not for a simple parameter.  This is
necessary, because the init forms of optional parameters occur
in a lexical environment in which prior parameters are
visible. The test case for this is that (lambda (x : (y x)))
must not produce a warning about unbound x.

1 files changed, 1 insertions, 0 deletions

diff --git a/eval.c b/eval.c
index 399c61c4..6880a457 100644
--- a/eval.c
+++ b/eval.c
@@ -994,6 +994,7 @@ static val expand_params_rec(val params, val menv,
       not_bindable_error(form, param);
     } else {
       param_ex = param;
+      new_menv = make_var_shadowing_env(menv, cons(param, nil));
     }
 
     {