From: Stefan Monnier <monnier@iro.umontreal.ca>
Date: Mon, 15 Feb 2021 17:07:52 +0000 (-0500)
Subject: * lisp/emacs-lisp/macroexp.el (macroexp--expand-all): Warn on empty let bodies
X-Git-Tag: emacs-28.0.90~3713
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=d41a4ad4ae6f25c3cbc90aaaa33781821bb655c5;p=emacs.git

* lisp/emacs-lisp/macroexp.el (macroexp--expand-all): Warn on empty let bodies
---

diff --git a/lisp/emacs-lisp/macroexp.el b/lisp/emacs-lisp/macroexp.el
index 13ff5ef2eda..0934e43e66a 100644
--- a/lisp/emacs-lisp/macroexp.el
+++ b/lisp/emacs-lisp/macroexp.el
@@ -299,7 +299,12 @@ Assumes the caller has bound `macroexpand-all-environment'."
       (`(,(and fun (or 'let 'let*)) . ,(or `(,bindings . ,body) dontcare))
        (macroexp--cons fun
                        (macroexp--cons (macroexp--all-clauses bindings 1)
-                                       (macroexp--all-forms body)
+                                       (if (null body)
+                                           (macroexp-unprogn
+                                            (macroexp--warn-and-return
+                                             (format "Empty %s body" fun)
+                                             nil t))
+                                         (macroexp--all-forms body))
                                        (cdr form))
                        form))
       (`(,(and fun `(lambda . ,_)) . ,args)