bug#15513: 24.2; isearch should clear selection in transient-mark-mode

bug#15513: 24.2; isearch should clear selection in transient-mark-mode

[Yuri Khan]

This bug report will be sent to the Bug-GNU-Emacs mailing list
and the GNU bug tracker at debbugs.gnu.org.  Please check that
the From: line contains a valid email address.  After a delay of up
to one day, you should receive an acknowledgement at that address.

Please write in English if possible, as the Emacs maintainers
usually do not have translators for other languages.

Please describe exactly what actions triggered the bug, and
the precise symptoms of the bug.  If you can, give a recipe
starting from `emacs -Q':

1. Start `emacs -Q'. It opens Emacs with the default text in *scratch*
buffer:
;; This buffer is for notes you don't want[...]
1a. cua-mode is off, transient-mark-mode is on.
2. Move point before This.
3. Select the word This by pressing Ctrl+Shift+Right arrow.
4. Invoke isearch by pressing Ctrl+S.
5. Enter `notes' as the search string.

Observed behavior:
* Selection is extended to include the word that was found by isearch.

Expected behavior:
* Since isearch is a point movement command and such commands deactivate
the selection in transient-mark-mode, I expect selection to be
deactivated.
* If I press Ctrl+Space before searching, this indicates an explicit
request for persistent selection. In this case, the current behavior of
isearch is correct.
* Additionally, it might be nice if pressing Ctrl+Shift+S behaved
similarly to Shift+arrow keys, unconditionally activating the selection
and extending/shrinking it to include the match.


In GNU Emacs 24.2.1 (x86_64-pc-linux-gnu, GTK+ Version 3.6.4)
 of 2013-04-09 on allspice, modified by Debian
Windowing system distributor `The X.Org Foundation', version 11.0.11303000
Configured using:
 `configure '--build' 'x86_64-linux-gnu' '--build' 'x86_64-linux-gnu'
 '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib'
 '--localstatedir=/var/lib' '--infodir=/usr/share/info'
 '--mandir=/usr/share/man' '--with-pop=yes'
 '--enable-locallisppath=/etc/emacs24:/etc/emacs:/usr/local/share/emacs/24.2/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.2/site-lisp:/usr/share/emacs/site-lisp'
 '--with-crt-dir=/usr/lib/x86_64-linux-gnu' '--with-x=yes'
 '--with-x-toolkit=gtk3' '--with-toolkit-scroll-bars'
 'build_alias=x86_64-linux-gnu' 'CFLAGS=-g -O2 -fstack-protector
 --param=ssp-buffer-size=4 -Wformat -Werror=format-security -Wall'
 'LDFLAGS=-Wl,-Bsymbolic-functions -Wl,-z,relro'
 'CPPFLAGS=-D_FORTIFY_SOURCE=2''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: en_RU.UTF-8
  value of $LC_NUMERIC: en_RU.UTF-8
  value of $LC_TIME: en_RU.UTF-8
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-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

Recent input:
M-x e m a <backspace> <backspace> <backspace> r e p
o s <backspace> r t <tab> <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
/usr/share/emacs/24.2/site-lisp/debian-startup hides
/usr/share/emacs/site-lisp/debian-startup
/usr/share/emacs/24.2/site-lisp/dictionaries-common/flyspell hides
/usr/share/emacs/24.2/lisp/textmodes/flyspell
/usr/share/emacs/24.2/site-lisp/dictionaries-common/ispell hides
/usr/share/emacs/24.2/lisp/textmodes/ispell

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail regexp-opt rfc2047 rfc2045
ietf-drums mm-util mail-prsvr mail-utils time-date tooltip ediff-hook
vc-hooks lisp-float-type mwheel x-win x-dnd tool-bar dnd fontset image
fringe lisp-mode register page menu-bar rfn-eshadow timer select
scroll-bar mouse jit-lock font-lock syntax facemenu font-core frame cham
georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao
korean japanese hebrew greek romanian slovak czech european ethiopic
indian cyrillic chinese case-table epa-hook jka-cmpr-hook help simple
abbrev minibuffer loaddefs button faces cus-face files text-properties
overlay sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process dbusbind
dynamic-setting system-font-setting font-render-setting move-toolbar gtk
x-toolkit x multi-tty emacs)

bug#15513: 24.2; isearch should clear selection in transient-mark-mode

[Drew Adams]

> 3. Select the word This by pressing Ctrl+Shift+Right arrow.
> 4. Invoke isearch by pressing Ctrl+S.
> 5. Enter `notes' as the search string.
> 
> Observed behavior:
> * Selection is extended to include the word that was found by isearch.

Yes, that is the expected (designed, documented) behavior.  This was
discussed in help-gnu-emacs, in (your) thread "automatic selection
during search".

> Expected behavior:
> * Since isearch is a point movement command and such commands deactivate
> the selection in transient-mark-mode, I expect selection to be
> deactivated.

Isearch is a lot more than just a point movement command.  And it might
or might not actually move point, in the end.  And there is no rule that
I know of that says that all point-movement commands (meaning what? any
command that moves point?) must deactivate the region before it acts.
What about `S-<right>'?  That's a point movement command - should it
too deactivate the region?

> * If I press Ctrl+Space before searching, this indicates an explicit
> request for persistent selection. In this case, the current behavior of
> isearch is correct.

You activated the region by doing `C-S-<right>', indicating an explicit
request for an active region.  Isearch extends the active region.
If you don't want that, then don't activate the region (or else deactivate
it) before invoking Isearch.

IOW, if it hurts, just don't do that.

bug#15513: 24.2; isearch should clear selection in transient-mark-mode

[Stefan Monnier]

retitle 15513 Isearch should clear shift-selected region
thanks

> 3. Select the word This by pressing Ctrl+Shift+Right arrow.
> 4. Invoke isearch by pressing Ctrl+S.
[...]
> Observed behavior:
> * Selection is extended to include the word that was found by isearch.
> Expected behavior:
> * Since isearch is a point movement command and such commands deactivate
> the selection in transient-mark-mode, I expect selection to be
> deactivated.
> * If I press Ctrl+Space before searching, this indicates an explicit
> request for persistent selection.  In this case, the current behavior of
> isearch is correct.

Actually, any highlighted region is a transient region.  Motion commands
deactivate the current selection only in the case where the selection
was made with shifted motion commands.

So C-s should only deactivate the region if it has been activated by
shifted motion commands.

> * Additionally, it might be nice if pressing Ctrl+Shift+S behaved
> similarly to Shift+arrow keys, unconditionally activating the selection
> and extending/shrinking it to include the match.

Yes, that would make a lot of sense, although C-S-s in my setup seems
never to reach Emacs (probably caught by something like
a window-manager).


        Stefan

bug#15513: Isearch should clear shift-selected region

[Lars Ingebrigtsen]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> Actually, any highlighted region is a transient region.  Motion commands
> deactivate the current selection only in the case where the selection
> was made with shifted motion commands.
>
> So C-s should only deactivate the region if it has been activated by
> shifted motion commands.

I think that makes sense -- but Emacs has worked this way for a long
time now, and I can't recall seeing many complaints about the behaviour
of `C-S-right C-s', so changing the behaviour may annoy people.

Anybody got an opinion here?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#15513: Isearch should clear shift-selected region

[Lars Ingebrigtsen]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> Stefan Monnier <monnier@iro.umontreal.ca> writes:
>
>> Actually, any highlighted region is a transient region.  Motion commands
>> deactivate the current selection only in the case where the selection
>> was made with shifted motion commands.
>>
>> So C-s should only deactivate the region if it has been activated by
>> shifted motion commands.
>
> I think that makes sense -- but Emacs has worked this way for a long
> time now, and I can't recall seeing many complaints about the behaviour
> of `C-S-right C-s', so changing the behaviour may annoy people.
>
> Anybody got an opinion here?

Nobody had an opinion in a month, so I think the least wrong solution
here is to not change the behaviour here, and I'm closing this bug
report.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no