bug#427: 23.0.60; emacsclient -t not working within "less"

bug#427: 23.0.60; emacsclient -t not working within "less"

[Andreas Amann]

1) start emacs with "emacs -q -f server-start &"
2) export VISUAL="emacsclient -t"
2) less .bashrc
3) within less type "v" to edit file with $VISUAL 

the result is that less writes a line 
"!emacsclient -t +18 .bashrc" on the terminal, but other than that the 
terminal is still showing the output of less. emacsclient 
is not taking over the terminal, and no editing is possible. 

Using "ps auxw" in another terminal, emacsclient appears in the
process list, though.  The only thing I can do in the "less terminal"
is to type "C-c" to resume viewing the .bashrc file.

The problem seems to be specific to "emacsclient -t", since both
export VISUAL="emacsclient -c"
and 
export VISUAL="emacs -nw"
work as expected.

The same problem occurs in both xterm and konsole. 




In GNU Emacs 23.0.60.1 (x86_64-unknown-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2008-06-11 on lnx0015f2465ec6
Windowing system distributor `The X.Org Foundation', version 11.0.10300000
configured using `configure  '--prefix=/home/aamann/local/emacs-cvs' 'LDFLAGS=-L/home/aamann/local/lib64' 'CPPFLAGS=-I/home/aamann/local/include''

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: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_IE.utf8
  value of $XMODIFIERS: @im=none
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  tool-bar-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
ESC [ > 0 ; 1 1 5 ; 0 c C-x C-c ESC [ > 0 ; 1 1 5 ; 
0 c ESC [ > 0 ; 1 1 5 ; 0 c M-x b u <tab> <backspace> 
<backspace> <backspace> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <menu-bar> 
<help-menu> <send-emacs-bug-report>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
When done with this frame, type C-x 5 0
(No files need saving)
When done with this frame, type C-x 5 0 [2 times]
Making completion list...
call-interactively: Text is read-only
Quit

bug#427: 23.0.60; emacsclient -t not working within "less"

[Chong Yidong]

From bug 427:

> 1) start emacs with "emacs -q -f server-start &"
> 2) export VISUAL="emacsclient -t"
> 2) less .bashrc
> 3) within less type "v" to edit file with $VISUAL 
>
> the result is that less writes a line "!emacsclient -t +18 .bashrc" on
> the terminal, but other than that the terminal is still showing the
> output of less. emacsclient is not taking over the terminal, and no
> editing is possible.

This looks like a serious bug that needs to be addressed.  Does anyone
have a clue about how to fix/debug this?

bug#427: 23.0.60; emacsclient -t not working within "less"

[Dan Nicolaescu]

Chong Yidong <cyd@stupidchicken.com> writes:

  > From bug 427:
  > 
  > > 1) start emacs with "emacs -q -f server-start &"
  > > 2) export VISUAL="emacsclient -t"
  > > 2) less .bashrc
  > > 3) within less type "v" to edit file with $VISUAL 
  > >
  > > the result is that less writes a line "!emacsclient -t +18 .bashrc" on
  > > the terminal, but other than that the terminal is still showing the
  > > output of less. emacsclient is not taking over the terminal, and no
  > > editing is possible.
  > 
  > This looks like a serious bug that needs to be addressed.  Does anyone
  > have a clue about how to fix/debug this?

You can edebug `server-process-filter'.  Doing that shows quickly the
problem: emacsclient passes the tty as: -tty /dev/tty.
/dev/tty means one thing for emacsclient and another one for emacs...

emacsclient.c computes the tty like this:

      tty_name = ttyname (fileno (stdin));

changing it to:

      tty_name = ttyname (fileno (stdout));

gets the right terminal and this problem seems to be fixed.