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.