bug#38206: 26.1; cl-prettyexpand incorrectly expands pushing to structures

["Braun Gábor" <braungb88@gmail.com>]

Hi,

Create file test.el:

(require 'cl-lib)
(cl-defstruct test slot)
(cl-prettyexpand '(push 1 (test-slot foo)))
(message "%s" (buffer-string))


Let Emacs evaluate the file:

$ emacs -Q -batch -l ./test.el
Expanding...
Formatting...


(let* ((v test-slot)
       (v (or (cl-block test-p
                (and (memq (type-of foo) cl-struct-test-tags) t))
              (signal 'wrong-type-argument (list 'test foo))))
       (v (aref foo 1)))
  (\(setf\ cl-block\) (cons 1 (cl-block v v v)) v v v))


The form in the output is obviously an incorrect expansion of
(push 1 (test-slot foo)).
Two errors are
(1) the reference to (non-existent) free variable `test-slot' in the 
first
line and
(2) calling the nonexistent function `(setf cl-block)' in the last line.

Best wishes,

     Gábor


In GNU Emacs 26.1 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.24.4)
 of 2019-02-03, modified by Debian built on zam904
Windowing system distributor 'The X.Org Foundation', version 
11.0.12004000
System Description:	Debian GNU/Linux 10 (buster)


Configured using:
 'configure --build x86_64-linux-gnu --prefix=/usr
 --sharedstatedir=/var/lib --libexecdir=/usr/lib
 --localstatedir=/var/lib --infodir=/usr/share/info
 --mandir=/usr/share/man --enable-libsystemd --with-pop=yes
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usr/share/emacs/site-lisp
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 x86_64-linux-gnu --prefix=/usr --sharedstatedir=/var/lib
 --libexecdir=/usr/lib --localstatedir=/var/lib
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 --with-pop=yes
 --enable-locallisppath=/etc/emacs:/usr/local/share/emacs/26.1/site-
lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/26.1/site-lisp:/
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 -D_FORTIFY_SOURCE=2' LDFLAGS=-Wl,-z,relro'

Configured features:
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ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
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Important settings:
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Major mode: Lisp Interaction

Minor modes in effect:
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Load-path shadows:
None found.

Features:
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Memory information:
((conses 16 99333 7644)
 (symbols 48 20637 2)
 (miscs 40 53 104)
 (strings 32 28919 1306)
 (string-bytes 1 758567)
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