Bug 31431

The grep manpage states under ENVIRONMENT VARIABLES:

       _N_GNU_nonoption_argv_flags_
              (Here N is grep's numeric process ID.)  If the  ith
              character  of  this environment variable's value is
              1, do not consider the ith operand of grep to be an
              option,  even if it appears to be one.  A shell can
              put this variable in the environment for each  com­
              mand  it  runs,  specifying  which operands are the
              results of file name wildcard expansion and  there­
              fore should not be treated as options.  This behav­
              ior is available only with the GNU C  library,  and
              only when POSIXLY_CORRECT is not set.

As far as I can see, this is incorrect, since out getopt() does not fetch
this environment variable.

Fix: 

remove that section from the manpage?
How-To-Repeat: 
(echo "foobar";echo "-G")|\
perl -e '
$ENV{"_".$$."_GNU_nonoption_argv_flags_"}="1";
exec "/usr/bin/grep","-G";
'

which should grep for "-G" but doesn't.

Further evidence is, that neither the source, nor the binary
contains the string "_GNU_nonoption_argv_flags_"

yoda:/usr/src/gnu/usr.bin/grep>grep _GNU_nonoption_argv_flags_ *.[ch]
yoda:/usr/src/gnu/usr.bin/grep>

and

yoda:~>ldd /usr/bin/grep
/usr/bin/grep:
        libgnuregex.so.2 => /usr/lib/libgnuregex.so.2 (0x28070000)
        libz.so.2 => /usr/lib/libz.so.2 (0x28078000)
        libc.so.4 => /usr/lib/libc.so.4 (0x28086000)

yoda:~>strings -a /usr/bin/grep /usr/lib/libgnuregex.so.2 /usr/lib/libz.so.2 /usr/lib/libc.so.4|grep _GNU_nonoption_argv_flags_
yoda:~>