getpass: get system declaration

[Bruno Haible]

On Solaris at least, getpass() is not declared in <unistd.h> or <stdlib.h> if
__EXTENSIONS__ is not defined. This fixes the autoconf test and the use of
<unistd.h> in lib/getpass.h.

By the way, on all systems (including glibc), getpass() is declared by
including <unistd.h>. I would propose to move its declaration in gnulib
from "getpass.h" to <unistd.h>, and to drop getpass.h. (getpass.h was
created in 2004, when we didn't have a <unistd.h> replacement.)
Objections?


2010-11-26  Bruno Haible  <address@hidden>

        getpass: Make sure to get system declaration on some platforms.
        * m4/getpass.m4 (gl_FUNC_GETPASS, gl_FUNC_GETPASS_GNU): Require
        gl_USE_SYSTEM_EXTENSIONS.
        * modules/getpass (Depends-on): Add extensions.

--- m4/getpass.m4.orig  Sat Nov 27 14:18:38 2010
+++ m4/getpass.m4       Sat Nov 27 14:14:39 2010
@@ -1,4 +1,4 @@
-# getpass.m4 serial 11
+# getpass.m4 serial 12
 dnl Copyright (C) 2002-2003, 2005-2006, 2009-2010 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
@@ -8,6 +8,9 @@
 # Provide a getpass() function if the system doesn't have it.
 AC_DEFUN([gl_FUNC_GETPASS],
 [
+  dnl Persuade Solaris <unistd.h> and <stdlib.h> to declare getpass().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   AC_REPLACE_FUNCS([getpass])
   AC_CHECK_DECLS_ONCE([getpass])
   if test $ac_cv_func_getpass = no; then
@@ -19,6 +22,9 @@
 # arbitrary length (not just 8 bytes as on HP-UX).
 AC_DEFUN([gl_FUNC_GETPASS_GNU],
 [
+  dnl Persuade Solaris <unistd.h> and <stdlib.h> to declare getpass().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   AC_CHECK_DECLS_ONCE([getpass])
   dnl TODO: Detect when GNU getpass() is already found in glibc.
   AC_LIBOBJ([getpass])
--- modules/getpass.orig        Sat Nov 27 14:18:38 2010
+++ modules/getpass     Sat Nov 27 14:12:35 2010
@@ -7,6 +7,7 @@
 m4/getpass.m4
 
 Depends-on:
+extensions
 fseeko
 getline
 stdbool