bug#70931: 29.3; scratch

bug#70931: 29.3; scratch

[Devon Sean McCullough]

$ Open -n -a /Applications/Emacs.app --args -Q

(find-file "/tmp/x") ; then Control-J

;; A buffer appears named x
;; containing the text #<buffer x>
;; but that text should instead be in the buffer named *scratch*

		Peace
			--Devon

In GNU Emacs 29.3 (build 1, x86_64-apple-darwin18.7.0, NS appkit-1671.60
  Version 10.14.6 (Build 18G9323)) of 2024-03-24 built on
  builder10-14.lan
Windowing system distributor 'Apple', version 10.3.1671
System Description:  Mac OS X 10.14.6

Configured using:
  'configure --with-ns '--enable-locallisppath=/Library/Application
  Support/Emacs/${version}/site-lisp:/Library/Application
  Support/Emacs/site-lisp' --with-modules 'CFLAGS=-DFD_SETSIZE=10000
  -DDARWIN_UNLIMITED_SELECT' --with-x-toolkit=no'

Configured features:
ACL GLIB GMP GNUTLS JPEG JSON LIBXML2 MODULES NOTIFY KQUEUE NS PDUMPER
PNG RSVG SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS TREE_SITTER ZLIB

Important settings:
   value of $LANG: en_US.UTF-8
   locale-coding-system: utf-8-unix

Major mode: Fundamental

Minor modes in effect:
   tooltip-mode: t
   global-eldoc-mode: t
   show-paren-mode: t
   electric-indent-mode: t
   mouse-wheel-mode: t
   tool-bar-mode: t
   menu-bar-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   blink-cursor-mode: t
   line-number-mode: t
   indent-tabs-mode: t
   transient-mark-mode: t
   auto-composition-mode: t
   auto-encryption-mode: t
   auto-compression-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message mailcap yank-media puny dired
dired-loaddefs rfc822 mml mml-sec password-cache epa derived epg rfc6068
epg-config gnus-util text-property-search time-date subr-x mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
cl-loaddefs cl-lib sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils rmc iso-transl tooltip cconv eldoc paren electric
uniquify ediff-hook vc-hooks lisp-float-type elisp-mode mwheel
term/ns-win ns-win ucs-normalize mule-util term/common-win tool-bar dnd
fontset image regexp-opt fringe tabulated-list replace newcomment
text-mode lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow
isearch easymenu timer select scroll-bar mouse jit-lock font-lock syntax
font-core term/tty-colors frame minibuffer nadvice seq simple cl-generic
indonesian philippine cham georgian utf-8-lang misc-lang vietnamese
tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek
romanian slovak czech european ethiopic indian cyrillic chinese
composite emoji-zwj charscript charprop case-table epa-hook
jka-cmpr-hook help abbrev obarray oclosure cl-preloaded button loaddefs
theme-loaddefs faces cus-face macroexp files window text-properties
overlay sha1 md5 base64 format env code-pages mule custom widget keymap
hashtable-print-readable backquote threads kqueue cocoa ns multi-tty
make-network-process emacs)

Memory information:
((conses 16 37812 5781)
  (symbols 48 5049 0)
  (strings 32 13286 1904)
  (string-bytes 1 381717)
  (vectors 16 10381)
  (vector-slots 8 162645 14115)
  (floats 8 21 23)
  (intervals 56 226 0)
  (buffers 984 12))

bug#70931: 29.3; scratch

[Eli Zaretskii]

> Date: Tue, 14 May 2024 04:52:59 -0500
> From: Devon Sean McCullough <Emacs-hacker2023@jovi.net>
> 
> $ Open -n -a /Applications/Emacs.app --args -Q
> 
> (find-file "/tmp/x") ; then Control-J
> 
> ;; A buffer appears named x
> ;; containing the text #<buffer x>
> ;; but that text should instead be in the buffer named *scratch*

Thanks.  This was caused by a too-eager simplification made back when
Emacs 26 was being developed.

Does the patch below give good results?

CC'ing Stefan in case he has comments.

diff --git a/lisp/progmodes/elisp-mode.el b/lisp/progmodes/elisp-mode.el
index 84814c9..d96fbbd 100644
--- a/lisp/progmodes/elisp-mode.el
+++ b/lisp/progmodes/elisp-mode.el
@@ -1557,13 +1557,16 @@ elisp--eval-last-sexp
   (pcase-let*
       ((`(,insert-value ,no-truncate ,char-print-limit)
         (eval-expression-get-print-arguments eval-last-sexp-arg-internal)))
-    ;; Setup the lexical environment if lexical-binding is enabled.
-    (elisp--eval-last-sexp-print-value
-     (eval (macroexpand-all
-            (eval-sexp-add-defvars
-             (elisp--eval-defun-1 (macroexpand (elisp--preceding-sexp)))))
-           lexical-binding)
-     (if insert-value (current-buffer) t) no-truncate char-print-limit)))
+    ;; The expression might change to a different buffer, so record that
+    ;; now.
+    (let ((output (if insert-value (current-buffer) t)))
+      ;; Setup the lexical environment if lexical-binding is enabled.
+      (elisp--eval-last-sexp-print-value
+       (eval (macroexpand-all
+              (eval-sexp-add-defvars
+               (elisp--eval-defun-1 (macroexpand (elisp--preceding-sexp)))))
+             lexical-binding)
+       output no-truncate char-print-limit))))
 
 (defun elisp--eval-last-sexp-print-value
     (value output &optional no-truncate char-print-limit)

bug#70931: 29.3; scratch

[Eli Zaretskii]

[Please use Reply All to reply, to keep the bug address CC;ed.]

> Date: Tue, 14 May 2024 06:40:48 -0500
> From: Devon Sean McCullough <Emacs-hacker2023@jovi.net>
> 
> I applied the patch and byte-compiled lisp/progmodes/elisp-mode.el
> but a freshly launched emacs does not see the patch
> unless I explicitly load the patched file.

That's expected, since elisp-mode is preloaded.

> P.S.  Yes, it works after I load it by hand.

Thanks for testing.

bug#70931: 29.3; scratch

[Eli Zaretskii]

> Cc: 70931@debbugs.gnu.org
> Date: Tue, 14 May 2024 14:57:42 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> 
> [Please use Reply All to reply, to keep the bug address CC;ed.]
> 
> > Date: Tue, 14 May 2024 06:40:48 -0500
> > From: Devon Sean McCullough <Emacs-hacker2023@jovi.net>
> > 
> > I applied the patch and byte-compiled lisp/progmodes/elisp-mode.el
> > but a freshly launched emacs does not see the patch
> > unless I explicitly load the patched file.
> 
> That's expected, since elisp-mode is preloaded.
> 
> > P.S.  Yes, it works after I load it by hand.
> 
> Thanks for testing.

Now installed on the master branch, and closing the bug.