bug#64730: 30.0.50; Mark activation doesn't work after insert

bug#64730: 30.0.50; Mark activation doesn't work after insert

[Bruno Boal]

Dear maintainers,

I'm trying to evaluate the following snippet in emacs -Q, however as
soon as I try to insert a character, the region is not highlighted
anymore. `activate- mark' doesn't make it work either. Whereas
interactively with `exchange-point-and-mark' the region gets proper highlight.

       (progn
         (insert "")
         (push-mark (line-beginning-position) :no-message :activate))

       (progn
         (insert "a")
         (push-mark (line-beginning-position) :no-message :activate))

All the best,
Bruno Boal


In GNU Emacs 30.0.50 (build 4, x86_64-pc-linux-gnu, X toolkit, Xaw3d
 scroll bars) of 2023-06-18 built on bb-hp-tiny
Repository revision: 1b0348d95934a66d9991a7331ab55e1b9a6c1367
Repository branch: makepkg
Windowing system distributor 'The X.Org Foundation', version 11.0.12101008
System Description: Manjaro Linux

Configured using:
 'configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
 --localstatedir=/var --mandir=/usr/share/man --with-gameuser=:games
 --with-modules --without-libotf --without-m17n-flt --without-gconf
 --with-native-compilation=yes --with-xinput2 --with-x-toolkit=lucid
 --with-xft --with-xaw3d --without-cairo --with-sound=no
 --with-tree-sitter --without-gpm --without-compress-install
 '--program-transform-name=s/\([ec]tags\)/\1.emacs/'
 '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'
 LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now'

Configured features:
ACL DBUS FREETYPE GIF GLIB GMP GNUTLS GSETTINGS HARFBUZZ JPEG JSON LCMS2
LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY PDUMPER PNG RSVG
SECCOMP SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS TREE_SITTER WEBP X11
XAW3D XDBE XFT XIM XINPUT2 XPM LUCID ZLIB

Important settings:
  value of $LC_COLLATE: C
  value of $LC_MESSAGES: en_US.UTF-8
  value of $LC_MONETARY: pt_PT.UTF-8
  value of $LC_NUMERIC: pt_PT.UTF-8
  value of $LC_TIME: pt_PT.UTF-8
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

bug#64730: 30.0.50; Mark activation doesn't work after insert

[Eli Zaretskii]

tags 64730 notabug
thanks

> Cc: public@protesilaos.com
> From: Bruno Boal <egomet@bboal.com>
> Date: Wed, 19 Jul 2023 12:17:21 +0100
> 
> I'm trying to evaluate the following snippet in emacs -Q, however as
> soon as I try to insert a character, the region is not highlighted
> anymore. `activate- mark' doesn't make it work either. Whereas
> interactively with `exchange-point-and-mark' the region gets proper highlight.
> 
>        (progn
>          (insert "")
>          (push-mark (line-beginning-position) :no-message :activate))
> 
>        (progn
>          (insert "a")
>          (push-mark (line-beginning-position) :no-message :activate))

This is the intended behavior.  The ELisp manual says in the node "The
Mark":

 -- Variable: deactivate-mark
     If an editor command sets this variable non-‘nil’, then the editor
     command loop deactivates the mark after the command returns (if
     Transient Mark mode is enabled).  All the primitives that change
     the buffer set ‘deactivate-mark’, to deactivate the mark when the
     command is finished.  Setting this variable makes it buffer-local.

     To write Lisp code that modifies the buffer without causing
     deactivation of the mark at the end of the command, bind
     ‘deactivate-mark’ to ‘nil’ around the code that does the
     modification.  For example:

          (let (deactivate-mark)
            (insert " "))

bug#64730: 30.0.50; Mark activation doesn't work after insert

[Bruno Boal]

Thank you for such a quick and helpful reply.
Best regards,
BB

Eli Zaretskii <eliz@gnu.org> writes:

> tags 64730 notabug
> thanks
>
>> Cc: public@protesilaos.com
>> From: Bruno Boal <egomet@bboal.com>
>> Date: Wed, 19 Jul 2023 12:17:21 +0100
>> 
>> I'm trying to evaluate the following snippet in emacs -Q, however as
>> soon as I try to insert a character, the region is not highlighted
>> anymore. `activate- mark' doesn't make it work either. Whereas
>> interactively with `exchange-point-and-mark' the region gets proper highlight.
>> 
>>        (progn
>>          (insert "")
>>          (push-mark (line-beginning-position) :no-message :activate))
>> 
>>        (progn
>>          (insert "a")
>>          (push-mark (line-beginning-position) :no-message :activate))
>
> This is the intended behavior.  The ELisp manual says in the node "The
> Mark":
>
>  -- Variable: deactivate-mark
>      If an editor command sets this variable non-‘nil’, then the editor
>      command loop deactivates the mark after the command returns (if
>      Transient Mark mode is enabled).  All the primitives that change
>      the buffer set ‘deactivate-mark’, to deactivate the mark when the
>      command is finished.  Setting this variable makes it buffer-local.
>
>      To write Lisp code that modifies the buffer without causing
>      deactivation of the mark at the end of the command, bind
>      ‘deactivate-mark’ to ‘nil’ around the code that does the
>      modification.  For example:
>
>           (let (deactivate-mark)
>             (insert " "))

bug#64730: 30.0.50; Mark activation doesn't work after insert

[Eli Zaretskii]

> From: Bruno Boal <egomet@bboal.com>
> Cc: 64730@debbugs.gnu.org, public@protesilaos.com
> Date: Thu, 20 Jul 2023 09:28:48 +0100
> 
> 
> Thank you for such a quick and helpful reply.

Thanks, I'm therefore closing this bug.