The thread-safe problem about the functions of glibc.

Hi,

  I consider that the function "fgetgrent_r()" of glibc-2.3.2
  should be thread-safe.
  (File name is "grp/fgetgrent_r.c")

  I think that the function will become a thread-safe,
  when you compile the function with "-D_IO_MTSAFE_IO" option.

  Would you modify the Makefile to set up the
  macro "_IO_MTSAFE_IO" and to compile it?

  5 functions shown below have the same problem.

    - fgetpwent_r() : -D_IO_MTSAFE_IO (File name : pwd/fgetpwent_r.c)
    - fgetspent_r() : -D_IO_MTSAFE_IO (File name : shadow/fgetspent_r.c)
    - getmntent_r() : -D_IO_MTSAFE_IO (File name : misc/mntent_r.c)
    - putgrent()    : -D_IO_MTSAFE_IO (File name : grp/putgrent.c)
    - putspent()    : -D_IO_MTSAFE_IO (File name : shadow/putspent.c)

Best Regards,
Shunichi Sagawa.