bug#30010: 25.3; changing layout in Windows 8.1 causes endless scroll in echo-area

bug#30010: 25.3; changing layout in Windows 8.1 causes endless scroll in echo-area

[Kireev Artur]

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I have Emacs 25.3.1(x86_64-w64-mingw32), downloaded from

http://ftp.gnu.org/gnu/emacs/windows/



When I run Emacs on my system Windows 8.1 x86_64, where I have 2 layouts

(ru & us) and then chang layot from one language to another, I recive

an error '<scroll> is undefined' in echo-area.







In GNU Emacs 25.3.1 (x86_64-w64-mingw32)

of 2017-09-27 built on LAPHROAIG

Windowing system distributor 'Microsoft Corp.', version 6.3.9600

Configured using:

'configure --without-dbus --without-compress-install 'CFLAGS=-O2

-static -g3' PKG_CONFIG_PATH=/mingw64/lib/pkgconfig'



Configured features:

XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY ACL GNUTLS LIBXML2 ZLIB

TOOLKIT_SCROLL_BARS



Important settings:

  value of $LANG: en_US, ru_RU

  locale-coding-system: cp1251



Major mode: Emacs-Lisp



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



Recent messages:

<C-scroll> is undefined [2 times]

<scroll> is undefined [4 times]

delete-backward-char: Text is read-only [3 times]

<scroll> is undefined [14 times]

mwheel-scroll: End of buffer [2 times]

<scroll> is undefined

mwheel-scroll: End of buffer [5 times]

<scroll> is undefined

mwheel-scroll: End of buffer

<scroll> is undefined [31 times]



Load-path shadows:

None found.



Features:

(shadow sort mail-extr emacsbug message cl-macs format-spec rfc822 mml

mml-sec password-cache epg gnus-util mm-decode mm-bodies mm-encode

mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047

rfc2045 ietf-drums mm-util help-fns mail-prsvr mail-utils edmacro kmacro

flyspell ispell light-blue-theme .loaddefs el-get el-get-autoloading

el-get-list-packages el-get-dependencies el-get-build el-get-status pp

el-get-methods el-get-fossil el-get-svn el-get-pacman el-get-github-zip

el-get-github-tar el-get-http-zip el-get-http-tar el-get-hg el-get-go

el-get-git-svn el-get-fink el-get-emacswiki el-get-http el-get-notify

el-get-emacsmirror el-get-github el-get-git el-get-elpa package

epg-config seq byte-opt el-get-darcs el-get-cvs el-get-bzr el-get-brew

el-get-builtin el-get-apt-get el-get-recipes el-get-byte-compile subr-x

el-get-custom cl-seq el-get-core autoload lisp-mnt bytecomp byte-compile

cl-extra help-mode easymenu cconv cl gv cl-loaddefs pcase cl-lib dired

time-date mule-util tooltip eldoc electric uniquify ediff-hook vc-hooks

lisp-float-type mwheel dos-w32 ls-lisp disp-table w32-win w32-vars

term/common-win tool-bar dnd fontset image regexp-opt fringe

tabulated-list newcomment elisp-mode lisp-mode prog-mode register page

menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock font-lock

syntax facemenu font-core frame cl-generic 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 charscript case-table epa-hook jka-cmpr-hook help

simple abbrev 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

w32notify w32 multi-tty make-network-process emacs)



Memory information:

((conses 16 112245 6045)

(symbols 56 22592 0)

(miscs 48 96 163)

(strings 32 24388 3481)

(string-bytes 1 688275)

(vectors 16 15839)

(vector-slots 8 462442 4390)

(floats 8 186 57)

(intervals 56 452 10)

(buffers 976 19))

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bug#30010: 25.3; changing layout in Windows 8.1 causes endless scroll in echo-area

[Eli Zaretskii]

> From: Kireev Artur <kireev.artur@live.ru>
> Date: Sat, 6 Jan 2018 16:26:21 +0000
> 
> I have Emacs 25.3.1(x86_64-w64-mingw32), downloaded from 
> 
> http://ftp.gnu.org/gnu/emacs/windows/
> 
>  
> 
> When I run Emacs on my system Windows 8.1 x86_64, where I have 2 layouts
> (ru & us) and then chang layot from one language to another, I recive
> an error '<scroll> is undefined' in echo-area.

Please describe how you change the keyboard layout (mouse? Alt-Shift?
something else?), and also please type "C-h l" (the letter ell, not
the digit one) after this error happens, and show the full contents of
the *Help* buffer produced by "C-h l".

Thanks.

bug#30010: 25.3; changing layout in Windows 8.1 causes endless scroll in echo-area

[Eli Zaretskii]

> From: Kireev Artur <kireev.artur@live.ru>
> Date: Sun, 7 Jan 2018 10:53:53 +0000
> 
> Ohhh, sorry for disturbing, error caused by capslang -- utility makes windows switch layouts by CapsLock, without it there is no errors.

Thanks for letting us know.  I'm therefore closing this bug.

bug#30010: 25.3; changing layout in Windows 8.1 causes endless scroll in echo-area

[martin rudalics]

 > Thanks for letting us know.  I'm therefore closing this bug.

Couldn't we tell users how to prevent Emacs from fiddling with such
key bindings?

martin

bug#30010: 25.3; changing layout in Windows 8.1 causes endless scroll in echo-area

[Eli Zaretskii]

> Date: Sun, 07 Jan 2018 17:09:10 +0100
> From: martin rudalics <rudalics@gmx.at>
> CC: 30010@debbugs.gnu.org
> 
>  > Thanks for letting us know.  I'm therefore closing this bug.
> 
> Couldn't we tell users how to prevent Emacs from fiddling with such
> key bindings?

I thought about mentioning this in PROBLEMS, but it sounded too
obscure even for that.  I could be convinced, though.  Did you mean
PROBLEMS or did you mean something else?

bug#30010: 25.3; changing layout in Windows 8.1 causes endless scroll in echo-area

[martin rudalics]

 >> Couldn't we tell users how to prevent Emacs from fiddling with such
 >> key bindings?
 >
 > I thought about mentioning this in PROBLEMS, but it sounded too
 > obscure even for that.  I could be convinced, though.  Did you mean
 > PROBLEMS or did you mean something else?

It looks to me as if now on Windows (1) Emacs grasps key combinations
before anyone else gets hold of them and (2) if it doesn't find an
appropriate binding for them, emit a warning unless it's a combination
reserved for Windows itself.  For example, on XP I use ahk to emulate
the Aero combination of

lwindow key + left key

via

ctrl + lwindow + alt + left key

This works with all other applications and also in a "normal" emacs
where I assign

(setq w32-lwindow-modifier 'hyper)	; lwindow is hyper

But with emacs -Q I get the warning

<C-M-lwindow> is undefined

although I apparently don't get it in later invocations of the same
executable.  I think (2) is a bad idea and there should be an option
to turn off such warnings.  Unfortunately, I have not been able to
understand how this mechanism works nowadays.

martin

bug#30010: 25.3; changing layout in Windows 8.1 causes endless scroll in echo-area

[Eli Zaretskii]

> Date: Mon, 08 Jan 2018 10:52:48 +0100
> From: martin rudalics <rudalics@gmx.at>
> CC: kireev.artur@live.ru, 30010@debbugs.gnu.org
> 
>  >> Couldn't we tell users how to prevent Emacs from fiddling with such
>  >> key bindings?
>  >
>  > I thought about mentioning this in PROBLEMS, but it sounded too
>  > obscure even for that.  I could be convinced, though.  Did you mean
>  > PROBLEMS or did you mean something else?
> 
> It looks to me as if now on Windows (1) Emacs grasps key combinations
> before anyone else gets hold of them and (2) if it doesn't find an
> appropriate binding for them, emit a warning unless it's a combination
> reserved for Windows itself.

Are you talking about Emacs 26 or later?  This bug report is about
Emacs 25, where AFAIR the above was not true.

> For example, on XP I use ahk to emulate the Aero combination of
> 
> lwindow key + left key
> 
> via
> 
> ctrl + lwindow + alt + left key
> 
> This works with all other applications and also in a "normal" emacs
> where I assign
> 
> (setq w32-lwindow-modifier 'hyper)	; lwindow is hyper
> 
> But with emacs -Q I get the warning
> 
> <C-M-lwindow> is undefined
> 
> although I apparently don't get it in later invocations of the same
> executable.  I think (2) is a bad idea and there should be an option
> to turn off such warnings.  Unfortunately, I have not been able to
> understand how this mechanism works nowadays.

Maybe we finally have a reason to provide a user facility for
disabling the keyboard hook.  (It would have to be on master, I think,
as AFAIR it is not very trivial, but maybe I misremember, or missed
some easy way of doing that.)

bug#30010: 25.3; changing layout in Windows 8.1 causes endless scroll in echo-area

[martin rudalics]

 > Are you talking about Emacs 26 or later?  This bug report is about
 > Emacs 25, where AFAIR the above was not true.

I didn't notice that.  So Capslang, instead of consuming the capslock,
emits a scroll keystroke which Windows passes on to Emacs.  This looks
weird enough indeed to not be mentioned anywhere.

 > Maybe we finally have a reason to provide a user facility for
 > disabling the keyboard hook.  (It would have to be on master, I think,
 > as AFAIR it is not very trivial, but maybe I misremember, or missed
 > some easy way of doing that.)

I think you already disable them during debugging which IIRC here
inhibits, for example, using the lwindow key as modifier in the
debugged Emacs.

martin

bug#30010: 25.3; changing layout in Windows 8.1 causes endless scroll in echo-area

[Eli Zaretskii]

> Date: Tue, 09 Jan 2018 10:38:45 +0100
> From: martin rudalics <rudalics@gmx.at>
> CC: kireev.artur@live.ru, 30010@debbugs.gnu.org
> 
>  > Maybe we finally have a reason to provide a user facility for
>  > disabling the keyboard hook.  (It would have to be on master, I think,
>  > as AFAIR it is not very trivial, but maybe I misremember, or missed
>  > some easy way of doing that.)
> 
> I think you already disable them during debugging

Yes, but only if you start Emacs from the debugger.  If you attach the
debugger, the hook is not disabled, because at the time I saw no easy
way of disabling it in the middle of a session.

bug#30010: 25.3; changing layout in Windows 8.1 causes endless scroll in echo-area

[martin rudalics]

 > Yes, but only if you start Emacs from the debugger.  If you attach the
 > debugger, the hook is not disabled, because at the time I saw no easy
 > way of disabling it in the middle of a session.

So this is both hairy and dependent on the version of Windows used.
Really bad.

martin