* bug#33492: 27.0.50; desktop-locals-to-save won't consider buffer-undo-list as local
@ 2018-11-24 20:54 Terje Larsen
2018-11-28 1:23 ` Glenn Morris
0 siblings, 1 reply; 5+ messages in thread
From: Terje Larsen @ 2018-11-24 20:54 UTC (permalink / raw)
To: 33492
Add buffer-undo-list to be saved by desktop-save:
(cl-pushnew 'buffer-undo-list desktop-locals-to-save :test #'equal)
Open a file:
C-x C-f ~/sample.txt
Input text such as:
Lorem ipsum dolor sit amet
Remove the two last words:
M-2 M-DEL
Save the desktop:
M-x desktop-save
... Restart Emacs ...
Load the desktop:
M-x desktop-read
Execute undo operation:
C-/
At this point I expect the undo operations from the previous session
to be successful.
It seems like this has been mentioned at StackExchange amongst other
places before:
https://emacs.stackexchange.com/questions/3725/why-is-the-buffer-undo-list-excluded-from-buffer-local-variables
I can verify that the issue stems from desktop-save relying on the C-function
buffer-local-variables and this function does not include the variable
buffer-undo-list.
Due to this it will be ignored from being saved by the desktop-save command.
Proposed in the StackExchange post is to append the buffer-undo-list
in the desktop-save
function. But perhaps it should be included in the C-function? Or does
that perhaps cause
other issues?
Personally I have solved it by using an advice:
(defun +append-buffer-undo-list-to-buffer-local-variables-advice
(orig-fn &rest args)
"Override `buffer-local-variables' and call ORIG-FN with ARGS.
There is a bug in Emacs where the `buffer-undo-list' data is
missing from the output of `buffer-local-variables'. This
advice temporarily overrides the function and appends the
missing data."
(let ((orig-buffer-local-variables-fn (symbol-function
'buffer-local-variables)))
(cl-letf (((symbol-function 'buffer-local-variables)
#'(lambda () (append (funcall
orig-buffer-local-variables-fn)
`(,(cons 'buffer-undo-list
buffer-undo-list))))))
(apply orig-fn args))))
(advice-add #'desktop-buffer-info :around
#'+append-buffer-undo-list-to-buffer-local-variables-advice)
I hope this "long-standing" bug would allow more people to utilize a
persistent undo without
jumping through hoops.
Thanks!
In GNU Emacs 27.0.50 (build 2, x86_64-apple-darwin18.0.0, NS
appkit-1671.00 Version 10.14 (Build 18A391))
of 2018-11-07 built on C02V91MHHV2Q.local
Repository revision: 811d9291fcfb12d87bad277d4e8b25152129d73d
Windowing system distributor 'Apple', version 10.3.1671
System Description: Mac OS X 10.14.1
Recent messages:
Desktop: 1 frame, 1 buffer restored.
You can run the command ‘desktop-read’ with M-x d-rea RET
Desktop: 1 frame, 1 buffer restored.
user-error: No further undo information [2 times]
user-error: Beginning of history; no preceding item
user-error: End of history; no default available
Configured using:
'configure --disable-dependency-tracking --disable-silent-rules
--enable-locallisppath=/usr/local/share/emacs/site-lisp
--infodir=/usr/local/Cellar/emacs/HEAD-811d929_1/share/info/emacs
--prefix=/usr/local/Cellar/emacs/HEAD-811d929_1 --with-gnutls
--without-x --with-xml2 --without-dbus --with-imagemagick --with-rsvg
--with-ns --disable-ns-self-contained'
Configured features:
RSVG IMAGEMAGICK GLIB NOTIFY KQUEUE ACL GNUTLS LIBXML2 ZLIB
TOOLKIT_SCROLL_BARS NS THREADS LCMS2 GMP
Important settings:
value of $LC_ALL: en_US.UTF-8
value of $LANG: en_US.UTF-8
locale-coding-system: utf-8-unix
Major mode: Text
Minor modes in effect:
tooltip-mode: t
global-eldoc-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
auto-composition-mode: t
auto-encryption-mode: t
auto-compression-mode: t
line-number-mode: t
transient-mark-mode: t
Load-path shadows:
None found.
Features:
(shadow sort mail-extr emacsbug message rmc puny seq byte-opt gv
bytecomp byte-compile cconv dired dired-loaddefs format-spec rfc822 mml
mml-sec password-cache epa derived epg epg-config gnus-util rmail
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rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045
ietf-drums mm-util mail-prsvr mail-utils thingatpt cl-seq cl-extra
help-mode easymenu desktop frameset cl-loaddefs cl-lib elec-pair tooltip
eldoc electric uniquify ediff-hook vc-hooks lisp-float-type 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 elisp-mode lisp-mode prog-mode register page menu-bar
rfn-eshadow isearch timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core term/tty-colors frame cl-generic cham georgian
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japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european
ethiopic indian cyrillic chinese composite charscript charprop
case-table epa-hook jka-cmpr-hook help simple abbrev obarray minibuffer
cl-preloaded nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote threads kqueue cocoa ns
lcms2 multi-tty make-network-process emacs)
Memory information:
((conses 16 208523 10884)
(symbols 48 20326 1)
(strings 32 30075 1669)
(string-bytes 1 808523)
(vectors 16 35932)
(vector-slots 8 729980 19992)
(floats 8 51 198)
(intervals 56 240 0)
(buffers 992 13))
^ permalink raw reply [flat|nested] 5+ messages in thread
* bug#33492: 27.0.50; desktop-locals-to-save won't consider buffer-undo-list as local
2018-11-24 20:54 bug#33492: 27.0.50; desktop-locals-to-save won't consider buffer-undo-list as local Terje Larsen
@ 2018-11-28 1:23 ` Glenn Morris
2018-11-28 21:49 ` Glenn Morris
0 siblings, 1 reply; 5+ messages in thread
From: Glenn Morris @ 2018-11-28 1:23 UTC (permalink / raw)
To: Terje Larsen; +Cc: 33492
Terje Larsen wrote:
> https://emacs.stackexchange.com/questions/3725/why-is-the-buffer-undo-list-excluded-from-buffer-local-variables
>
> I can verify that the issue stems from desktop-save relying on the
> C-function buffer-local-variables and this function does not include
> the variable buffer-undo-list.
Thanks for the report.
This issue (buffer-local-variables does not include buffer-undo-list)
is present since Emacs 24.3, due to 36429c8, which moved undo_list to
the end of struct buffer.
^ permalink raw reply [flat|nested] 5+ messages in thread
* bug#33492: 27.0.50; desktop-locals-to-save won't consider buffer-undo-list as local
2018-11-28 1:23 ` Glenn Morris
@ 2018-11-28 21:49 ` Glenn Morris
2019-01-30 0:30 ` Glenn Morris
0 siblings, 1 reply; 5+ messages in thread
From: Glenn Morris @ 2018-11-28 21:49 UTC (permalink / raw)
To: Terje Larsen; +Cc: 33492
Glenn Morris wrote:
> This issue (buffer-local-variables does not include buffer-undo-list)
> is present since Emacs 24.3, due to 36429c8, which moved undo_list to
> the end of struct buffer.
The following works, but I don't know if it is the best solution.
--- i/src/buffer.c
+++ w/src/buffer.c
@@ -1266,6 +1266,20 @@ buffer_lisp_local_variables (struct buffer *buf, bool clone)
return result;
}
+Lisp_Object
+buffer_local_variables_1 (struct buffer *buf, int offset)
+{
+ int idx = PER_BUFFER_IDX (offset);
+ if ((idx == -1 || PER_BUFFER_VALUE_P (buf, idx))
+ && SYMBOLP (PER_BUFFER_SYMBOL (offset)))
+ {
+ Lisp_Object sym = PER_BUFFER_SYMBOL (offset);
+ Lisp_Object val = per_buffer_value (buf, offset);
+ return EQ (val, Qunbound) ? sym : Fcons (sym, val);
+ }
+ return Qnil;
+}
+
DEFUN ("buffer-local-variables", Fbuffer_local_variables,
Sbuffer_local_variables, 0, 1, 0,
doc: /* Return an alist of variables that are buffer-local in BUFFER.
@@ -1277,6 +1291,7 @@ No argument or nil as argument means use current buffer as BUFFER. */)
{
struct buffer *buf = decode_buffer (buffer);
Lisp_Object result = buffer_lisp_local_variables (buf, 0);
+ Lisp_Object tem;
/* Add on all the variables stored in special slots. */
{
@@ -1284,18 +1299,16 @@ No argument or nil as argument means use current buffer as BUFFER. */)
FOR_EACH_PER_BUFFER_OBJECT_AT (offset)
{
- idx = PER_BUFFER_IDX (offset);
- if ((idx == -1 || PER_BUFFER_VALUE_P (buf, idx))
- && SYMBOLP (PER_BUFFER_SYMBOL (offset)))
- {
- Lisp_Object sym = PER_BUFFER_SYMBOL (offset);
- Lisp_Object val = per_buffer_value (buf, offset);
- result = Fcons (EQ (val, Qunbound) ? sym : Fcons (sym, val),
- result);
- }
+ tem = buffer_local_variables_1 (buf, offset);
+ if (!NILP (tem))
+ result = Fcons (tem, result);
}
}
+ tem = buffer_local_variables_1 (buf, PER_BUFFER_VAR_OFFSET (undo_list));
+ if (!NILP (tem))
+ result = Fcons (tem, result);
+
return result;
}
^ permalink raw reply [flat|nested] 5+ messages in thread
* bug#33492: 27.0.50; desktop-locals-to-save won't consider buffer-undo-list as local
2018-11-28 21:49 ` Glenn Morris
@ 2019-01-30 0:30 ` Glenn Morris
2020-05-18 17:57 ` Glenn Morris
0 siblings, 1 reply; 5+ messages in thread
From: Glenn Morris @ 2019-01-30 0:30 UTC (permalink / raw)
To: 33492; +Cc: Terje Larsen
Glenn Morris wrote:
>> This issue (buffer-local-variables does not include buffer-undo-list)
>> is present since Emacs 24.3, due to 36429c8, which moved undo_list to
>> the end of struct buffer.
>
> The following works, but I don't know if it is the best solution.
>
> --- i/src/buffer.c
> +++ w/src/buffer.c
> @@ -1266,6 +1266,20 @@ buffer_lisp_local_variables (struct buffer *buf, bool clone)
> return result;
> }
>
> +Lisp_Object
> +buffer_local_variables_1 (struct buffer *buf, int offset)
> +{
> + int idx = PER_BUFFER_IDX (offset);
> + if ((idx == -1 || PER_BUFFER_VALUE_P (buf, idx))
> + && SYMBOLP (PER_BUFFER_SYMBOL (offset)))
> + {
> + Lisp_Object sym = PER_BUFFER_SYMBOL (offset);
> + Lisp_Object val = per_buffer_value (buf, offset);
> + return EQ (val, Qunbound) ? sym : Fcons (sym, val);
> + }
> + return Qnil;
> +}
> +
> DEFUN ("buffer-local-variables", Fbuffer_local_variables,
> Sbuffer_local_variables, 0, 1, 0,
> doc: /* Return an alist of variables that are buffer-local in BUFFER.
> @@ -1277,6 +1291,7 @@ No argument or nil as argument means use current buffer as BUFFER. */)
> {
> struct buffer *buf = decode_buffer (buffer);
> Lisp_Object result = buffer_lisp_local_variables (buf, 0);
> + Lisp_Object tem;
>
> /* Add on all the variables stored in special slots. */
> {
> @@ -1284,18 +1299,16 @@ No argument or nil as argument means use current buffer as BUFFER. */)
>
> FOR_EACH_PER_BUFFER_OBJECT_AT (offset)
> {
> - idx = PER_BUFFER_IDX (offset);
> - if ((idx == -1 || PER_BUFFER_VALUE_P (buf, idx))
> - && SYMBOLP (PER_BUFFER_SYMBOL (offset)))
> - {
> - Lisp_Object sym = PER_BUFFER_SYMBOL (offset);
> - Lisp_Object val = per_buffer_value (buf, offset);
> - result = Fcons (EQ (val, Qunbound) ? sym : Fcons (sym, val),
> - result);
> - }
> + tem = buffer_local_variables_1 (buf, offset);
> + if (!NILP (tem))
> + result = Fcons (tem, result);
> }
> }
>
> + tem = buffer_local_variables_1 (buf, PER_BUFFER_VAR_OFFSET (undo_list));
> + if (!NILP (tem))
> + result = Fcons (tem, result);
> +
> return result;
> }
I was going to apply this, there having been no comments, but then I
noticed that since the advent of portable dumper (or since 978cf88 at
least), it's not completely right. It adds an entry for buffer-undo-list
to buffer-local-variables, but with key = "nil" rather than
"buffer-undo-list". Which implies that
PER_BUFFER_SYMBOL (PER_BUFFER_VAR_OFFSET (undo_list))
now returns nil instead of 'buffer-undo-list.
^ permalink raw reply [flat|nested] 5+ messages in thread
* bug#33492: 27.0.50; desktop-locals-to-save won't consider buffer-undo-list as local
2019-01-30 0:30 ` Glenn Morris
@ 2020-05-18 17:57 ` Glenn Morris
0 siblings, 0 replies; 5+ messages in thread
From: Glenn Morris @ 2020-05-18 17:57 UTC (permalink / raw)
To: 33492-done
Version: 28.1
No comments in over a year, so I have pushed a simple-minded fix.
I am sure someone will now fix it properly within a week.
commit 86594a3ddb
Date: Mon May 18 10:54:14 2020 -0700
Restore buffer-undo-list to buffer-local-variables
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-05-18 17:57 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2018-11-24 20:54 bug#33492: 27.0.50; desktop-locals-to-save won't consider buffer-undo-list as local Terje Larsen
2018-11-28 1:23 ` Glenn Morris
2018-11-28 21:49 ` Glenn Morris
2019-01-30 0:30 ` Glenn Morris
2020-05-18 17:57 ` Glenn Morris
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