/etc/environment (related with bug #28446)

[Francesco Potorti` <F.Potorti@cnuce.cnr.it>]

I see  that there  is no policy  described in  /usr/doc/debian-policy about
/etc/environment, while I think there should be one.

/etc/environment can be  used as an initialiser for  login, by uncommenting
the proper  line in /etc/login.defs.  In  this case, each  line should have
the form
	name=value
where value  is any string,  starting from the  equal sign to  the newline,
without any  quoting.  The names are  exported by the login  program to its
subprocesses.   This mechanism  is independent  of the  shell used  and its
quoting and exporting conventions.

Another place where /etc/environment is called for is in the
/etc/X11/Xsession script:

  # global Xsession file -- used by both xdm and xinit (startx)

  # If /etc/environment is present, source it. It's useful to put default
  # environment settings in this file, and then source it both here and in
  # /etc/profile.
  if [ -f /etc/environment ]; then
    . /etc/environment
  fi

As  you see,  the  file is  sourced, which  means  that the  values of  the
variables defined should be properly quoted.  Moreover, export instructions
are needed inside /etc/environment, unless  one uses the "set -o allexport"
instruction of  bash or ksh,  which is almost  unusable as it  triggers bug
#23857.   The same happens  if one  follows the  suggestion in  the comment
inside  Xsession,  that is,  if  /etc/environment  is  sourced from  within
/etc/profile.

This  means  that the  usages  suggested  in  login.defs and  Xsession  are
incompatible, and one of them should  be chosen, and comments should be put
in  one of  those  files stating  that  the suggested  use  is contrary  to
Debian's policy.