* bug#54133: 29.0.50; Buffer-menu-visit-tags-table disrupts non-tags buffers
@ 2022-02-23 21:37 Bob Rogers
2022-02-24 9:19 ` martin rudalics
2022-02-24 15:15 ` Eli Zaretskii
0 siblings, 2 replies; 7+ messages in thread
From: Bob Rogers @ 2022-02-23 21:37 UTC (permalink / raw)
To: 54133
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In GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.20, cairo version 1.16.0)
of 2022-02-19 built on orion
Repository revision: 563bb08c5998f82e034a0aa1b48dce29fb9bc375
Repository branch: rgr-smtpmail-env-from
Windowing system distributor 'The X.Org Foundation', version 11.0.12003000
System Description: openSUSE Leap 15.3
Configured using:
'configure --with-dbus=no --with-gsettings=no --with-gif=ifavailable
--with-tiff=no --with-gnutls=yes --with-gconf=no'
Configured features:
ACL CAIRO FREETYPE GIF GLIB GMP GNUTLS HARFBUZZ JPEG LIBSELINUX LIBXML2
MODULES NOTIFY INOTIFY PDUMPER PNG RSVG SECCOMP SOUND SQLITE3 THREADS
TOOLKIT_SCROLL_BARS X11 XDBE XIM XPM GTK3 ZLIB
To reproduce:
In master ecaedf2117cb015ad4028e4d6fc7058608c98096:
1. "emacs -Q &"
2. Visit pretty much any random file that is NOT a tags file; for
this purpose, lisp/abbrev.el from the source tree will do nicely.
3. Type "C-x C-b" to get the "*Buffer List*" window to appear.
4. Type "C-x o" to move the to the buffer list, then move to the
abbrev.el line, and type "t" to invoke Buffer-menu-visit-tags-table on
it (which I seem to do accidentally more often than I care to admit).
This produces the error message:
user-error: File /scratch/rogers/emacs/lisp/abbrev.el is not a valid tags table
but the abbrev.el buffer is left in tags-table-mode, and any undo
information is thrown away.
The attached patch addresses the problem in a straightforward way by
making Buffer-menu-visit-tags-table prompt the user for buffers not
already in tags-table-mode.
The real problem is that visit-tags-table assumes that the user knows
what they're doing, and makes these irreversible changes before being
sure of having a valid tags table. That would be a harder thing to fix,
though -- and might not deal as well with my buffer-menu typos. ;-}
-- Bob Rogers
http://www.rgrjr.com/
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From 05d2d1855cddc8d5c310d718c07d91ae861b8436 Mon Sep 17 00:00:00 2001
From: Bob Rogers <rogers@rgrjr.com>
Date: Wed, 23 Feb 2022 16:23:17 -0500
Subject: [PATCH] Make Buffer-menu-visit-tags-table more circumspect
* lisp/buff-menu.el:
+ (Buffer-menu-visit-tags-table): Ask before visit-tags-table on a
buffer not already in tags-table-mode, lest it destroy state.
---
| 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
--git a/lisp/buff-menu.el b/lisp/buff-menu.el
index 50c2c155ca..0bed539008 100644
--- a/lisp/buff-menu.el
+++ b/lisp/buff-menu.el
@@ -530,10 +530,21 @@ Buffer-menu-multi-occur
(defun Buffer-menu-visit-tags-table ()
"Visit the tags table in the buffer on this line. See `visit-tags-table'."
(interactive nil Buffer-menu-mode)
- (let ((file (buffer-file-name (Buffer-menu-buffer t))))
- (if file
- (visit-tags-table file)
- (error "Specified buffer has no file"))))
+ (let* ((buffer (Buffer-menu-buffer t))
+ (file (buffer-file-name buffer)))
+ (or file
+ (error "Specified buffer has no file"))
+ ;; Ensure that it's really a tags file buffer (or the user at
+ ;; least believes it should be). Otherwise, visit-tags-table will
+ ;; change the mode and discard any undo information.
+ (if (not (or (eq (with-current-buffer buffer
+ major-mode)
+ 'tags-table-mode)
+ (yes-or-no-p
+ (format "%s is not a tags table; visit as such anyway? "
+ buffer))))
+ (error "Aborted."))
+ (visit-tags-table file)))
(defun Buffer-menu-1-window ()
"Select this line's buffer, alone, in full frame."
--
2.34.1
^ permalink raw reply related [flat|nested] 7+ messages in thread
* bug#54133: 29.0.50; Buffer-menu-visit-tags-table disrupts non-tags buffers
2022-02-23 21:37 bug#54133: 29.0.50; Buffer-menu-visit-tags-table disrupts non-tags buffers Bob Rogers
@ 2022-02-24 9:19 ` martin rudalics
2022-02-24 15:15 ` Eli Zaretskii
1 sibling, 0 replies; 7+ messages in thread
From: martin rudalics @ 2022-02-24 9:19 UTC (permalink / raw)
To: Bob Rogers, 54133
> The real problem is that visit-tags-table assumes that the user knows
> what they're doing, and makes these irreversible changes before being
> sure of having a valid tags table. That would be a harder thing to fix,
> though -- and might not deal as well with my buffer-menu typos. ;-}
IIUC the problem is that ‘tags-verify-table' calls 'tags-table-mode'
first and 'verify-tags-table-function' afterwards.
martin
^ permalink raw reply [flat|nested] 7+ messages in thread
* bug#54133: 29.0.50; Buffer-menu-visit-tags-table disrupts non-tags buffers
2022-02-23 21:37 bug#54133: 29.0.50; Buffer-menu-visit-tags-table disrupts non-tags buffers Bob Rogers
2022-02-24 9:19 ` martin rudalics
@ 2022-02-24 15:15 ` Eli Zaretskii
2022-02-24 17:30 ` Bob Rogers
1 sibling, 1 reply; 7+ messages in thread
From: Eli Zaretskii @ 2022-02-24 15:15 UTC (permalink / raw)
To: Bob Rogers; +Cc: 54133
> From: Bob Rogers <rogers@rgrjr.com>
> Date: Wed, 23 Feb 2022 16:37:11 -0500
>
> 1. "emacs -Q &"
>
> 2. Visit pretty much any random file that is NOT a tags file; for
> this purpose, lisp/abbrev.el from the source tree will do nicely.
>
> 3. Type "C-x C-b" to get the "*Buffer List*" window to appear.
>
> 4. Type "C-x o" to move the to the buffer list, then move to the
> abbrev.el line, and type "t" to invoke Buffer-menu-visit-tags-table on
> it (which I seem to do accidentally more often than I care to admit).
> This produces the error message:
>
> user-error: File /scratch/rogers/emacs/lisp/abbrev.el is not a valid tags table
>
> but the abbrev.el buffer is left in tags-table-mode, and any undo
> information is thrown away.
>
> The attached patch addresses the problem in a straightforward way by
> making Buffer-menu-visit-tags-table prompt the user for buffers not
> already in tags-table-mode.
>
> The real problem is that visit-tags-table assumes that the user knows
> what they're doing, and makes these irreversible changes before being
> sure of having a valid tags table. That would be a harder thing to fix,
> though -- and might not deal as well with my buffer-menu typos. ;-}
Does the alternative patch below give good results?
diff --git a/lisp/buff-menu.el b/lisp/buff-menu.el
index 50c2c15..179cc54 100644
--- a/lisp/buff-menu.el
+++ b/lisp/buff-menu.el
@@ -527,13 +527,18 @@ Buffer-menu-multi-occur
(multi-occur (Buffer-menu-marked-buffers) regexp nlines))
\f
+(autoload 'etags-verify-tags-table "etags")
(defun Buffer-menu-visit-tags-table ()
"Visit the tags table in the buffer on this line. See `visit-tags-table'."
(interactive nil Buffer-menu-mode)
- (let ((file (buffer-file-name (Buffer-menu-buffer t))))
- (if file
- (visit-tags-table file)
- (error "Specified buffer has no file"))))
+ (let* ((buf (Buffer-menu-buffer t))
+ (file (buffer-file-name buf)))
+ (cond
+ ((not file) (error "Specified buffer has no file"))
+ ((and buf (with-current-buffer buf
+ (etags-verify-tags-table)))
+ (visit-tags-table file))
+ (t (error "Specified buffer is not a tags-table")))))
(defun Buffer-menu-1-window ()
"Select this line's buffer, alone, in full frame."
^ permalink raw reply related [flat|nested] 7+ messages in thread
* bug#54133: 29.0.50; Buffer-menu-visit-tags-table disrupts non-tags buffers
2022-02-24 15:15 ` Eli Zaretskii
@ 2022-02-24 17:30 ` Bob Rogers
2022-02-24 17:42 ` Eli Zaretskii
0 siblings, 1 reply; 7+ messages in thread
From: Bob Rogers @ 2022-02-24 17:30 UTC (permalink / raw)
To: Eli Zaretskii; +Cc: 54133
From: Eli Zaretskii <eliz@gnu.org>
Date: Thu, 24 Feb 2022 17:15:54 +0200
> From: Bob Rogers <rogers@rgrjr.com>
> Date: Wed, 23 Feb 2022 16:37:11 -0500
>
> . . .
>
> The real problem is that visit-tags-table assumes that the user knows
> what they're doing, and makes these irreversible changes before being
> sure of having a valid tags table. That would be a harder thing to fix,
> though -- and might not deal as well with my buffer-menu typos. ;-}
Does the alternative patch below give good results?
This does ineed work, and I had considered something similar, but was
concerned that it would not be as robust. etags-verify-tags-table is
called from etags-recognize-tags-table, which is only a part of the
tags-table-format-functions extension mechanism used by
initialize-new-tags-table. So to avoid breaking this mechanism I would
either have had to call initialize-new-tags-table and have it possibly
set unwanted local variables, or delve more deeply into the internals by
running tags-table-format-functions myself.
In short, I thought checking the major mode was the better choice,
since the file was already present in a buffer.
-- Bob
^ permalink raw reply [flat|nested] 7+ messages in thread
* bug#54133: 29.0.50; Buffer-menu-visit-tags-table disrupts non-tags buffers
2022-02-24 17:30 ` Bob Rogers
@ 2022-02-24 17:42 ` Eli Zaretskii
2022-02-24 18:02 ` Bob Rogers
0 siblings, 1 reply; 7+ messages in thread
From: Eli Zaretskii @ 2022-02-24 17:42 UTC (permalink / raw)
To: Bob Rogers; +Cc: 54133
> From: Bob Rogers <rogers@rgrjr.com>
> Date: Thu, 24 Feb 2022 12:30:53 -0500
> Cc: 54133@debbugs.gnu.org
>
> From: Eli Zaretskii <eliz@gnu.org>
> Date: Thu, 24 Feb 2022 17:15:54 +0200
>
> > From: Bob Rogers <rogers@rgrjr.com>
> > Date: Wed, 23 Feb 2022 16:37:11 -0500
> >
> > . . .
> >
> > The real problem is that visit-tags-table assumes that the user knows
> > what they're doing, and makes these irreversible changes before being
> > sure of having a valid tags table. That would be a harder thing to fix,
> > though -- and might not deal as well with my buffer-menu typos. ;-}
>
> Does the alternative patch below give good results?
>
> This does ineed work, and I had considered something similar, but was
> concerned that it would not be as robust. etags-verify-tags-table is
> called from etags-recognize-tags-table, which is only a part of the
> tags-table-format-functions extension mechanism used by
> initialize-new-tags-table. So to avoid breaking this mechanism I would
> either have had to call initialize-new-tags-table and have it possibly
> set unwanted local variables, or delve more deeply into the internals by
> running tags-table-format-functions myself.
Maybe we should have a more thorough implementation in
etags-verify-tags-table, then. But that function's purpose is to do
what we need here.
> In short, I thought checking the major mode was the better choice,
> since the file was already present in a buffer.
But what if the file is already in a buffer, but not under the right
major-mode? E.g., what if the file was visited literally?
^ permalink raw reply [flat|nested] 7+ messages in thread
* bug#54133: 29.0.50; Buffer-menu-visit-tags-table disrupts non-tags buffers
2022-02-24 17:42 ` Eli Zaretskii
@ 2022-02-24 18:02 ` Bob Rogers
2022-02-24 20:00 ` Eli Zaretskii
0 siblings, 1 reply; 7+ messages in thread
From: Bob Rogers @ 2022-02-24 18:02 UTC (permalink / raw)
To: Eli Zaretskii; +Cc: 54133
From: Eli Zaretskii <eliz@gnu.org>
Date: Thu, 24 Feb 2022 19:42:14 +0200
> From: Bob Rogers <rogers@rgrjr.com>
> Date: Thu, 24 Feb 2022 12:30:53 -0500
>
> . . .
>
> This does ineed work, and I had considered something similar, but
> was concerned that it would not be as robust . . .
Maybe we should have a more thorough implementation in
etags-verify-tags-table, then. But that function's purpose is to do
what we need here.
That would require disentangling detection and initialization. Which
shouldn't be all that hard; it just seemed like more work than necessary
to scratch this particular itch.
> In short, I thought checking the major mode was the better choice,
> since the file was already present in a buffer.
But what if the file is already in a buffer, but not under the right
major-mode? E.g., what if the file was visited literally?
Ah, so you mean that Buffer-menu-visit-tags-table is normally meant to
introduce tags-table-mode in buffers not already there. I see now that
is implied by "Visit the tags table ..." in the command documentation.
In which case I withdraw my reservations.
And maybe I'll have a look at cleaning up etags initialization when I
get a chance . . .
-- Bob
^ permalink raw reply [flat|nested] 7+ messages in thread
* bug#54133: 29.0.50; Buffer-menu-visit-tags-table disrupts non-tags buffers
2022-02-24 18:02 ` Bob Rogers
@ 2022-02-24 20:00 ` Eli Zaretskii
0 siblings, 0 replies; 7+ messages in thread
From: Eli Zaretskii @ 2022-02-24 20:00 UTC (permalink / raw)
To: Bob Rogers; +Cc: 54133-done
> From: Bob Rogers <rogers@rgrjr.com>
> Date: Thu, 24 Feb 2022 13:02:40 -0500
> CC: 54133@debbugs.gnu.org
>
> Maybe we should have a more thorough implementation in
> etags-verify-tags-table, then. But that function's purpose is to do
> what we need here.
>
> That would require disentangling detection and initialization. Which
> shouldn't be all that hard; it just seemed like more work than necessary
> to scratch this particular itch.
>
> > In short, I thought checking the major mode was the better choice,
> > since the file was already present in a buffer.
>
> But what if the file is already in a buffer, but not under the right
> major-mode? E.g., what if the file was visited literally?
>
> Ah, so you mean that Buffer-menu-visit-tags-table is normally meant to
> introduce tags-table-mode in buffers not already there. I see now that
> is implied by "Visit the tags table ..." in the command documentation.
> In which case I withdraw my reservations.
Thanks, I installed the changes, and I'm marking this bug done.
> And maybe I'll have a look at cleaning up etags initialization when I
> get a chance . . .
TIA.
^ permalink raw reply [flat|nested] 7+ messages in thread
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-- links below jump to the message on this page --
2022-02-23 21:37 bug#54133: 29.0.50; Buffer-menu-visit-tags-table disrupts non-tags buffers Bob Rogers
2022-02-24 9:19 ` martin rudalics
2022-02-24 15:15 ` Eli Zaretskii
2022-02-24 17:30 ` Bob Rogers
2022-02-24 17:42 ` Eli Zaretskii
2022-02-24 18:02 ` Bob Rogers
2022-02-24 20:00 ` Eli Zaretskii
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