lisp/let-alist.el (let-alist): Evaluate `alist' only once.

2 files changed, 10 insertions, 3 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 8978bde017d..9828b845368 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2014-12-18  Artur Malabarba  <bruce.connor.am@gmail.com>
+
+        * let-alist.el (let-alist): Evaluate the `alist' argument only
+        once.
+
 2014-12-18  Sam Steingold  <sds@gnu.org>
 
         * emacs-lisp/package.el: Avoid compilation warning by declaring
diff --git a/lisp/let-alist.el b/lisp/let-alist.el
index 2efa027c449..8f02404cbdf 100644
--- a/lisp/let-alist.el
+++ b/lisp/let-alist.el
@@ -94,9 +94,11 @@ expands to
         .body
       .site))"
   (declare (indent 1) (debug t))
-  `(let ,(mapcar (lambda (x) `(,(car x) (cdr (assq ',(cdr x) ,alist))))
-                 (delete-dups (let-alist--deep-dot-search body)))
-     ,@body))
+  (let ((var (gensym "let-alist")))
+    `(let ((,var ,alist)
+           (let ,(mapcar (lambda (x) `(,(car x) (cdr (assq ',(cdr x) ,var))))
+                   (delete-dups (let-alist--deep-dot-search body)))
+             ,@body)))))
 
 (provide 'let-alist)