POSIX gettext() and chdir()

[Bruno Haible]

https://posix.rhansen.org/p/gettext_split
says (line 273):

  "The bindtextdomain() function shall not perform pathname resolution
   on dirname (that is done by the gettext family of functions)."

This is indeed how GNU gettext and GNU libc behave. However, this is
not optimal:

  1) If the dirname is not absolute, the application cannot use chdir()
     at various points and still expect gettext() to work.

  2) Storing a dirname over a long time and using it only later during
     the gettext() call opens the door to file system races.

A more modern approach would be to

  * have bindtextdomain() open() the given directory and store the
    resulting file descriptor,
  * have gettext() use openat() instead of open() for locating and opening
    the message catalogs.

Such changes have not been implemented in GNU gettext and glibc so far.
But it would be good to not preclude such an improved implementation.

Suggested wording:

  "It is unspecified whether the bindtextdomain() function performs
   pathname resolution on dirname, or whether that is done by the
   gettext family of functions."

Bruno