bug#19191: 24.4; su command in *shell* buffer does not work

[白井彰 <okshirai@gmail.com>]

echo $(tty) says:

not a tty      /* 24.4 */
/dev/pts/15    /* 24.3 */


/* 24.4 */
oomiya% telnet yokohama
yokohama% setenv DISPLAY oomiya:0.0
yokohama% i386/emacs-24.4/bin/emacs &
M-x shell
/* *shell* buffer (24.4) */
yokohama% ls -l $(tty)
not: No such file or directory
a: No such file or directory
tty: No such file or directory
yokohama% echo $(tty)
not a tty
yokohama% who am i
Must be attached to terminal for 'am I' option
yokohama% w
  9:26am  up 115 day(s), 32 min(s),  8 users,  load average: 3.02, 3.04, 3.06
User     tty           login@  idle   JCPU   PCPU  what
shirai   pts/17        9:13am    13     38     38  w
yokohama% ps -ef | grep emacs
  shirai  3308  3285   0 09:14:19 pts/17      0:39 i386/emacs-24.4/bin/emacs
  shirai  3178     1   0 09:11:12 ?           0:15 i386/emacs-24.3/src/emacs
  shirai  3670  3410   0 09:27:19 ?           0:00 grep emacs
yokohama% ptree 3308
360   /usr/lib/inet/inetd start
  3259  /usr/sbin/in.telnetd
    3262  -csh
      3285  csh
        3308  i386/emacs-24.4/bin/emacs
          3410  /bin/zsh -i
            3672  ptree 3308
yokohama% ps -efl | sort | nawk '{if ($4 ~ /360|3259|3262|3285|3308|3410|3672/) {print $0}}'
 0 S     root   360     1   0  40 20        ?   2183        ?   Aug 04 ?           0:49 /usr/lib/inet/inetd start
 0 S     root  3259   360   0  40 20        ?    936        ? 09:13:52 ?           0:00 /usr/sbin/in.telnetd
 0 S   shirai  3262  3259   0  40 20        ?   1140        ? 09:13:52 pts/17      0:00 -csh
 0 S   shirai  3285  3262   0  40 20        ?    597        ? 09:14:05 pts/17      0:00 csh
 0 O   shirai  3308  3285   0  40 20        ?  18970          09:14:19 pts/17      0:39 i386/emacs-24.4/bin/emacs
 0 S   shirai  3410  3308   0  70 20        ?    927        ? 09:17:45 ?           0:00 /bin/zsh -i
yokohama% tail -1 /var/adm/messages
Nov 27 11:59:20 yokohama su: [ID 810491 auth.crit] 'su root' failed for shirai on /dev/???

/* 24.3 */
oomiya% telnet yokohama
yokohama% setenv DISPLAY oomiya:0.0
yokohama% i386/emacs-24.3/src/emacs &
M-x shell
/* *shell* buffer (24.3) */
yokohama% ls -l $(tty)
lrwxrwxrwx   1 root     root          29 Jul 26  2012 /dev/pts/15 -> ../../devices/pseudo/pts@0:15
yokohama% echo $(tty)
/dev/pts/15
yokohama% who am i
shirai     /dev/pts/15  Nov 27 09:29
yokohama% w
  9:29am  up 115 day(s), 35 min(s),  8 users,  load average: 3.02, 3.03, 3.05
User     tty           login@  idle   JCPU   PCPU  what
shirai   pts/9        Tue 6pm 31:30  49:47         csh
yokohama% ps -ef | grep emacs
  shirai  3308  3285   0 09:14:19 pts/17      0:39 i386/emacs-24.4/bin/emacs
  shirai  3178     1   0 09:11:12 ?           0:15 i386/emacs-24.3/src/emacs
  shirai  3727  3198   0 09:30:12 pts/15      0:00 grep emacs
yokohama% ptree 3178
3178  i386/emacs-24.3/src/emacs
  3198  /bin/zsh -i
    3740  ptree 3178
yokohama% ps -efl | sort | nawk '{if ($4 ~ /3178|3198|3740/) {print $0}}'
 0 O   shirai  3178     1   0  40 20        ?  19270          09:11:12 ?           0:15 i386/emacs-24.3/src/emacs
 0 S   shirai  3198  3178   0  70 20        ?    927        ? 09:11:35 pts/15      0:00 /bin/zsh -i