Emacs doesn't set mark with C-<SPC> anymore after Xubuntu upgrade to 14.04

Emacs doesn't set mark with C-<SPC> anymore after Xubuntu upgrade to 14.04

[Timothée Flutre]

I just upgraded Xubuntu on my laptop from 13.10 to 14.04. I uninstalled and
re-installed Emacs and its version is 24.3.1. Everything is working fine
except the kill-yank system (copy-paste).

To investigate this, I opened a terminal (xfce4-terminal 0.6.3), launched
emacs inside it (emacs -nw), wrote a few dummy lines in *scratch* and
kill-yank one of them (C-space C-n Esc-w). But when I entered the last
command ("Esc-w"), the mini-buffer displayed the following message:

The mark is not set now, so there is no region

I had no idea what was going on because this was working fine all the time
I was using emacs for several years. So I looked up online and found in the
manual (
https://www.gnu.org/software/emacs/manual/html_node/emacs/Setting-Mark.html)
that C-<SPC> was used to set the mark. Same for C-@. And indeed, the latter
works fine even though the former doesn't.

On StackOverflow, I learned that C-<SPC> was not working likely due to the
fact that the terminal emulator wasn't properly transmitting C-<SPC> to
emacs (http://stackoverflow.com/a/16271042/597069).

My questions therefore are: should I get use to C-@? Why was C-<SPC>
working before and not anymore? Is there something to add to my .emacs
profile to make C-<SPC> work all the time with emacs v24+?

Thanks for your help!

Tim

Re: Emacs doesn't set mark with C-<SPC> anymore after Xubuntu upgrade to 14.04

[Bob Proulx]

Timothée Flutre wrote:
> To investigate this, I opened a terminal (xfce4-terminal 0.6.3), launched
> emacs inside it (emacs -nw), wrote a few dummy lines in *scratch* and
> ...
> On StackOverflow, I learned that C-<SPC> was not working likely due to the
> fact that the terminal emulator wasn't properly transmitting C-<SPC> to
> emacs (http://stackoverflow.com/a/16271042/597069).

I installed xfce4-terminal 0.6.3 on my Debian system.  I launched it.
I started emacs within it just as you have indicated.  For me C-SPC
works fine and I can set the mark using it.

This leads me to believe that for some reason your xfce4-terminal does
something different that is problematic for you.  I don't know the
answer but I would concentrate on the question of why your
xfce4-terminal does not pass C-SPC through as C-@.

  C-h c
  Describe key (or click or menu item):
  C-spacebar
  C-@ runs the command set-mark-command

Therefore I conclude that your xfce4-terminal should be doing the same
but does not.

There are many ways things might fail and therefore hard to
immediately diagnose why it isn't working.  I would try another
terminal emulator and see if it functions better.  I would try looking
at xmodmap to see if you have a customization that is remapping the
keyboard.  I would try xev to verify that control is sending Control_L
and that spacebar is sending a "space".  I would see if there is an
XFCE customization that might be affecting things.

I might try temporarily creating a pristine new user "guest42" or some
such and log in there just to verify the behavior with a pristine new
environment.  If it works there then you have confirmed that the
problem is in your normal environment somewhere.  You can delete the
temporary user account after you have completed testing with it.

I am sure there are many ways to debug this problem.

Bob

Re: Emacs doesn't set mark with C-<SPC> anymore after Xubuntu upgrade to 14.04

[Timothée Flutre]

Thanks everyone for your advice!

I created another user on my system but the same behavior happened (that
is, C-<SPC>) doesn't set the mark.

My problem was in fact due to IBus. I did the same as explained in this
answer (
https://ask.fedoraproject.org/en/question/10978/emacs-key-binding-ctrlspace-not-working-on-fedora-16-gnome-or-xfce/?answer=14990#post-id-14990).
I first opened IBus ($ ibus-setup) and there I changed Ctrl<space> into
Alt<space>. I hope it won't destroy anything, but at least C-<SPC> now sets
the mark in emacs.

Timothée Flutre


2014-05-22 1:18 GMT+02:00 Bob Proulx <bob@proulx.com>:

> Timothée Flutre wrote:
> > To investigate this, I opened a terminal (xfce4-terminal 0.6.3), launched
> > emacs inside it (emacs -nw), wrote a few dummy lines in *scratch* and
> > ...
> > On StackOverflow, I learned that C-<SPC> was not working likely due to
> the
> > fact that the terminal emulator wasn't properly transmitting C-<SPC> to
> > emacs (http://stackoverflow.com/a/16271042/597069).
>
> I installed xfce4-terminal 0.6.3 on my Debian system.  I launched it.
> I started emacs within it just as you have indicated.  For me C-SPC
> works fine and I can set the mark using it.
>
> This leads me to believe that for some reason your xfce4-terminal does
> something different that is problematic for you.  I don't know the
> answer but I would concentrate on the question of why your
> xfce4-terminal does not pass C-SPC through as C-@.
>
>   C-h c
>   Describe key (or click or menu item):
>   C-spacebar
>   C-@ runs the command set-mark-command
>
> Therefore I conclude that your xfce4-terminal should be doing the same
> but does not.
>
> There are many ways things might fail and therefore hard to
> immediately diagnose why it isn't working.  I would try another
> terminal emulator and see if it functions better.  I would try looking
> at xmodmap to see if you have a customization that is remapping the
> keyboard.  I would try xev to verify that control is sending Control_L
> and that spacebar is sending a "space".  I would see if there is an
> XFCE customization that might be affecting things.
>
> I might try temporarily creating a pristine new user "guest42" or some
> such and log in there just to verify the behavior with a pristine new
> environment.  If it works there then you have confirmed that the
> problem is in your normal environment somewhere.  You can delete the
> temporary user account after you have completed testing with it.
>
> I am sure there are many ways to debug this problem.
>
> Bob
>

Re: Emacs doesn't set mark with C-<SPC> anymore after Xubuntu upgrade to 14.04

[Robert Thorpe]

Timothée Flutre <timflutre@gmail.com> writes:

> that C-<SPC> was used to set the mark. Same for C-@. And indeed, the latter
> works fine even though the former doesn't.

There are lots of people on the internet complaining about similar
problems.  It could be your terminal, or it could be your window
manager or shell.  Some graphical shells rebind ctrl + space.  On my
system if I use the "Ibus" utility then it claims to remap ctrl + space,
but doesn't actually do it.  And it does something funny with C-z though
it claims to do nothing with that.

Another possibility is the "editable accelerators" in xfce-terminal.
That means if you press a keychord while going through one of it's menus
it will save that keychord as a shortcut to the menu entry.  You may
have accidentally done that.  It can be undone, see the xfce help.

BR,
Robert Thorpe

Re: Emacs doesn't set mark with C-<SPC> anymore after Xubuntu upgrade to 14.04

[Javier]

Try C-h l (view lossage) to view the keyboard input that emacs sees.
Possibly you need to remap the escape sequence with something like

(define-key function-key-map "\e[1;5A" '[C-up])


My advice is to use xterm instead of xfce-terminal.  It handles better
the passing of key combinations.