bug#45610: 27.1; Symbol’s function definition is void: seq-concatenate

[Eli Zaretskii]

> From:  Leo Liu <sdl.web@gmail.com>
> Cc: 45610@debbugs.gnu.org
> Date: Sat, 02 Jan 2021 22:22:35 +0800
> 
> On 2021-01-02 14:47 +0200, Eli Zaretskii wrote:
> > What did that expand to in Emacs 26?
> 
> The body of cl-concatenate before Emacs 27:
> 
> (pcase type
>    (`vector (apply #'vconcat sequences))
>    (`string (apply #'concat sequences))
>    (`list (apply #'append (append sequences '(nil))))
>    (_ (error "Not a sequence type name: %S" type)))

Thanks.  Then does the patch below fix the problem in Emacs 27.1?

diff --git a/lisp/emacs-lisp/cl-extra.el b/lisp/emacs-lisp/cl-extra.el
index 9c9da4a..a6e6619 100644
--- a/lisp/emacs-lisp/cl-extra.el
+++ b/lisp/emacs-lisp/cl-extra.el
@@ -556,6 +556,7 @@ cl-subseq
 (defun cl-concatenate (type &rest sequences)
   "Concatenate, into a sequence of type TYPE, the argument SEQUENCEs.
 \n(fn TYPE SEQUENCE...)"
+  (require 'seq)
   (apply #'seq-concatenate type sequences))
 
 ;;; List functions.