scm_def_{in,out,err}p

[Christopher Cramer]

In root.h, there are declarations for 7 ports, that exist for every
thread:

  SCM cur_inp;
  SCM cur_outp;
  SCM cur_errp;
  SCM def_inp;
  SCM def_outp;
  SCM def_errp;
  SCM cur_loadp;

and then macros to access them:

#define scm_cur_inp                     (scm_root->cur_inp)
#define scm_cur_outp                    (scm_root->cur_outp)
#define scm_cur_errp                    (scm_root->cur_errp)
#define scm_def_inp                     (scm_root->def_inp)
#define scm_def_outp                    (scm_root->def_outp)
#define scm_def_errp                    (scm_root->def_errp)
#define scm_cur_loadp                   (scm_root->cur_loadp)

The purpose of scm_cur_* is obvious, but what are scm_def_*
for? The only place they are used is in init.c, and there they
are only written to. They also don't seem to be documented 
anywhere (not in the manual, or in any comments, changelogs,
NEWS, or README).

-- 
Christopher Cramer <address@hidden> <http://www.pyro.net/~crayc/>
Quoi que vous fassiez, écrasez l'infâme, et aimez qui vous aime.
        -- Voltaire