From: Stefan Monnier <monnier@iro.umontreal.ca>
Date: Tue, 13 Oct 2015 13:48:16 +0000 (-0400)
Subject: * lisp/mpc.el (mpc-songs-refresh): Don't side-effect `active'
X-Git-Tag: emacs-25.0.90~1142
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=8610bd16e92c1a8639206847bd8c6ea523727cd5;p=emacs.git

* lisp/mpc.el (mpc-songs-refresh): Don't side-effect `active'

... since it might come straight from the memoizing table.
---

diff --git a/lisp/mpc.el b/lisp/mpc.el
index a5fc376eaea..21002ec5081 100644
--- a/lisp/mpc.el
+++ b/lisp/mpc.el
@@ -1960,7 +1960,7 @@ This is used so that they can be compared with `eq', which is needed for
             ;; I punt on it and just use file-name sorting, which does the
             ;; right thing if your library is properly arranged.
             (dolist (song (if dontsort active
-                            (sort active
+                            (sort (copy-sequence active)
                                   (lambda (song1 song2)
                                     (let ((cmp (mpc-compare-strings
                                                 (cdr (assq 'file song1))