Correct ttyslot header declaration conditions (bug 20051).

UNIX98 and XPG4 have ttyslot in <stdlib.h>.  glibc, however, has it in
<unistd.h>, for __USE_MISC || (__USE_XOPEN_EXTENDED && !__USE_UNIX98),
but no supported standard has it in <unistd.h>.

This patch adds a properly conditioned declaration to <stdlib.h> (only
enabled for the relevant standards, not for __USE_MISC or __USE_GNU).
The <unistd.h> declaration is restricted to __USE_MISC.  Some relevant
XFAILs are removed.

Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).

	[BZ #20051]
	* posix/unistd.h [__USE_XOPEN_EXTENDED && !__USE_UNIX98]
	(ttyslot): Do not declare.
	* stdlib/stdlib.h [__USE_XOPEN_EXTENDED && !__USE_XOPEN2K]
	(ttyslot): New prototype.
	* conform/Makefile (test-xfail-XPG4/unistd.h/conform): Remove
	variable.
	(test-xfail-UNIX98/stdlib.h/conform): Likewise.

1 files changed, 1 insertions, 2 deletions

diff --git a/posix/unistd.h b/posix/unistd.h
index 98ffcea649..625ba77da7 100644
--- a/posix/unistd.h
+++ b/posix/unistd.h
@@ -781,8 +781,7 @@ extern int ttyname_r (int __fd, char *__buf, size_t __buflen)
    with a terminal, zero if not.  */
 extern int isatty (int __fd) __THROW;
 
-#if defined __USE_MISC \
-    || (defined __USE_XOPEN_EXTENDED && !defined __USE_UNIX98)
+#ifdef __USE_MISC
 /* Return the index into the active-logins file (utmp) for
    the controlling terminal.  */
 extern int ttyslot (void) __THROW;