bug#65877: 29.1; line-number-at-pos crashes with args-out-of-range when ran using emacsclient

bug#65877: 29.1; line-number-at-pos crashes with args-out-of-range when ran using emacsclient

[Michaël Cadilhac]

How to reproduce: start with

$ emacs -Q

M-x server-start

Open a file with say 200 lines, scroll at the bottom, so that the
first line of the file is not at the top of the window.

Then in a shell, run:

$ emacsclient -e '(line-number-at-pos (window-start))'
*ERROR*: Args out of range: 146, 1, 1

This error is unexpected.  If the top of the window is visible in the
main emacs, this command returns 1.  If it isn't, it crashes.


Configuration details follow-----------------------------------------

In GNU Emacs 29.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.38,
cairo version 1.17.8)
Windowing system distributor 'The X.Org Foundation', version 11.0.12101008
System Description: Arch Linux

Configured using:
 'configure --sysconfdir=/etc --prefix=/usr --libexecdir=/usr/lib
 --with-tree-sitter --localstatedir=/var --with-cairo
 --disable-build-details --with-harfbuzz --with-libsystemd
 --with-modules --with-x-toolkit=gtk3 'CFLAGS=-march=x86-64
 -mtune=generic -O2 -pipe -fno-plt -fexceptions -Wp,-D_FORTIFY_SOURCE=2
 -Wformat -Werror=format-security -fstack-clash-protection
 -fcf-protection -g
 -ffile-prefix-map=/build/emacs/src=/usr/src/debug/emacs -flto=auto'
 'LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now -flto=auto''

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
JSON LCMS2 LIBOTF LIBSYSTEMD LIBXML2 M17N_FLT MODULES NOTIFY INOTIFY
PDUMPER PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS
TREE_SITTER WEBP X11 XDBE XIM XINPUT2 XPM GTK3 ZLIB

Important settings:
  value of $LANG: en_US.utf8
  locale-coding-system: utf-8-unix

Major mode: Fundamental

Minor modes in effect:
  server-mode: t
  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 server rmc iso-transl tooltip cconv eldoc paren
electric uniquify ediff-hook vc-hooks lisp-float-type elisp-mode mwheel
term/x-win x-win term/common-win x-dnd 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 dbusbind inotify lcms2
dynamic-setting system-font-setting font-render-setting cairo
move-toolbar gtk x-toolkit xinput2 x multi-tty make-network-process
emacs)

Memory information:
((conses 16 37743 8089)
 (symbols 48 5363 0)
 (strings 32 13739 2164)
 (string-bytes 1 390492)
 (vectors 16 9609)
 (vector-slots 8 155004 11315)
 (floats 8 22 19)
 (intervals 56 233 0)
 (buffers 984 12))

bug#65877: 29.1; line-number-at-pos crashes with args-out-of-range when ran using emacsclient

[Eli Zaretskii]

tags 65877 notabug
thanks

> From: Michaël Cadilhac <michael@cadilhac.name>
> Date: Mon, 11 Sep 2023 16:07:42 -0500
> 
> How to reproduce: start with
> 
> $ emacs -Q
> 
> M-x server-start
> 
> Open a file with say 200 lines, scroll at the bottom, so that the
> first line of the file is not at the top of the window.
> 
> Then in a shell, run:
> 
> $ emacsclient -e '(line-number-at-pos (window-start))'
> *ERROR*: Args out of range: 146, 1, 1

This is a cockpit error, not a bug.  The doc string of
line-number-at-pos says:

  line-number-at-pos is a built-in function in ‘src/fns.c’.

  (line-number-at-pos &optional POSITION ABSOLUTE)

  Return the line number at POSITION in the current buffer.
                                     ^^^^^^^^^^^^^^^^^^^^^

So the correct form to evaluate is this:

  $ emacsclient -e "(with-current-buffer (window-buffer) (line-number-at-pos (window-start)))"

IOW, you must make sure the buffer of the selected window is current
when the server evaluates the expression.  It is not guaranteed by
default:

  $ emacsclient -e "(message \"%s\" (current-buffer))"
  " *server*"

bug#65877: 29.1; line-number-at-pos crashes with args-out-of-range when ran using emacsclient

[Michaël Cadilhac]

On Tue, Sep 12, 2023 at 6:29 AM Eli Zaretskii <eliz@gnu.org> wrote:

> This is a cockpit error, not a bug.  The doc string of
> line-number-at-pos says:
>
>   line-number-at-pos is a built-in function in ‘src/fns.c’.
>
>   (line-number-at-pos &optional POSITION ABSOLUTE)
>
>   Return the line number at POSITION in the current buffer.
>                                      ^^^^^^^^^^^^^^^^^^^^^
>
> So the correct form to evaluate is this:
>
>   $ emacsclient -e "(with-current-buffer (window-buffer) (line-number-at-pos (window-start)))"

Fantastic, thanks for your help, and apologies for the noise.

bug#65877: 29.1; line-number-at-pos crashes with args-out-of-range when ran using emacsclient

[Eli Zaretskii]

> From: Michaël Cadilhac <michael@cadilhac.name>
> Date: Tue, 12 Sep 2023 10:59:08 -0500
> Cc: 65877@debbugs.gnu.org
> 
> On Tue, Sep 12, 2023 at 6:29 AM Eli Zaretskii <eliz@gnu.org> wrote:
> 
> > This is a cockpit error, not a bug.  The doc string of
> > line-number-at-pos says:
> >
> >   line-number-at-pos is a built-in function in ‘src/fns.c’.
> >
> >   (line-number-at-pos &optional POSITION ABSOLUTE)
> >
> >   Return the line number at POSITION in the current buffer.
> >                                      ^^^^^^^^^^^^^^^^^^^^^
> >
> > So the correct form to evaluate is this:
> >
> >   $ emacsclient -e "(with-current-buffer (window-buffer) (line-number-at-pos (window-start)))"
> 
> Fantastic, thanks for your help, and apologies for the noise.

No sweat; I'm therefore closing this bug.