bugfix: dohash expander not making shadowing env.

* eval.c (do_expand): When a dohash special form is
expanded, a macro shadowing environment must be
created for the two variables that it binds and the
body must be expanded in that environment, to
protect the variables from symbol macros.

1 files changed, 2 insertions, 1 deletions

diff --git a/eval.c b/eval.c
index 74713d72..a5f74b5a 100644
--- a/eval.c
+++ b/eval.c
@@ -3785,7 +3785,8 @@ static val do_expand(val form, val menv)
       val body = rest(rest(form));
       val hashform_ex = expand(hashform, menv);
       val resform_ex = expand(resform, menv);
-      val body_ex = expand_progn(body, menv);
+      val new_menv = make_var_shadowing_env(menv, list(keysym, valsym, nao));
+      val body_ex = expand_progn(body, new_menv);
 
       if (hashform == hashform_ex && resform == resform_ex && body == body_ex)
         return form;