GNU bug report logs - #25154
25.1; Bindings in cl-letf are in reverse order

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Package: emacs;

Reported by: Alex <agrambot <at> gmail.com>

Date: Fri, 9 Dec 2016 23:55:02 UTC

Severity: minor

Tags: notabug

Found in version 25.1

Done: Philipp Stephani <p.stephani2 <at> gmail.com>

Bug is archived. No further changes may be made.

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Alex <agrambot <at> gmail.com>
To: bug-gnu-emacs <at> gnu.org
Subject: 25.1; Bindings in cl-letf are in reverse order
Date: Fri, 09 Dec 2016 17:36:15 -0600

Compare the following:

(let ((x 5)
      (x 6))
  (+ x 10))

=> 16

(cl-letf ((x 5)
          (x 6))
  (+ x 10))

=> 15


This also occurs when using non-trivial places:

(setq v (vector 1 2 3 4 5))

(cl-letf (((aref v 1) 10)
          ((aref v 1) 20))
  (aref v 1))

=> 10


I ran into this when using two different setters that sometimes
indirectly modify the same variable. The current behaviour makes the
result of that unexpected.
This bug report was last modified 8 years and 150 days ago.

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