getlogin_r: Work around portability problem on OSF/1.

* m4/getlogin_r.m4 (gl_FUNC_GETLOGIN_R): Detect the OSF/1 problem.
* lib/unistd.in.h (getlogin_r): Replace if REPLACE_GETLOGIN_R is set.
* lib/getlogin_r.c (getlogin_r): When getlogin_r exists, invoke it and
test for a truncated result.
* m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Initialize REPLACE_GETLOGIN_R.
* modules/unistd (Makefile.am): Substitute REPLACE_GETLOGIN_R.
* modules/getlogin_r (Depends-on): Add memchr.
* doc/posix-functions/getlogin_r.texi: Mention the OSF/1 problem.

2 files changed, 21 insertions, 3 deletions

diff --git a/lib/getlogin_r.c b/lib/getlogin_r.c
index c1e7435876..27b84048d1 100644
--- a/lib/getlogin_r.c
+++ b/lib/getlogin_r.c
@@ -1,6 +1,6 @@
 /* Provide a working getlogin_r for systems which lack it.
 
-   Copyright (C) 2005-2007, 2009-2010 Free Software Foundation, Inc.
+   Copyright (C) 2005-2007, 2010 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -39,6 +39,7 @@ extern char *getlogin (void);
 int
 getlogin_r (char *name, size_t size)
 {
+#undef getlogin_r
 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
   /* Native Windows platform.  */
   DWORD sz;
@@ -59,6 +60,14 @@ getlogin_r (char *name, size_t size)
         return ENOENT;
     }
   return 0;
+#elif HAVE_GETLOGIN_R
+  /* Platform with a getlogin_r() function.  */
+  int ret = getlogin_r (name, size);
+
+  if (ret == 0 && memchr (name, '\0', size) == NULL)
+    /* name contains a truncated result.  */
+    return ERANGE;
+  return ret;
 #else
   /* Platform with a getlogin() function.  */
   char *n;
diff --git a/lib/unistd.in.h b/lib/unistd.in.h
index 40ac3781de..1dd06bfa61 100644
--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -712,13 +712,22 @@ _GL_WARN_ON_USE (getlogin, "getlogin is unportable - "
      ${LOGNAME-$USER}        on Unix platforms,
      $USERNAME               on native Windows platforms.
  */
-# if !@HAVE_DECL_GETLOGIN_R@
+# if @REPLACE_GETLOGIN_R@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define getlogin_r rpl_getlogin_r
+#  endif
+_GL_FUNCDECL_RPL (getlogin_r, int, (char *name, size_t size)
+                                   _GL_ARG_NONNULL ((1)));
+_GL_CXXALIAS_RPL (getlogin_r, int, (char *name, size_t size));
+# else
+#  if !@HAVE_DECL_GETLOGIN_R@
 _GL_FUNCDECL_SYS (getlogin_r, int, (char *name, size_t size)
                                    _GL_ARG_NONNULL ((1)));
-# endif
+#  endif
 /* Need to cast, because on Solaris 10 systems, the second argument is
                                                      int size.  */
 _GL_CXXALIAS_SYS_CAST (getlogin_r, int, (char *name, size_t size));
+# endif
 _GL_CXXALIASWARN (getlogin_r);
 #elif defined GNULIB_POSIXCHECK
 # undef getlogin_r