Revamp lchown so that it lives in unistd.h where it belongs.

* lib/lchown.h: Remove.
* lib/dirchownmod.c: Don't include lib/lchown.h.
* lib/fchownat.c: Likewise.
* lib/openat.c: Likewise.
* lib/lchown.c (REPLACE_CHOWN): Define to 0 if the system chown
does not follow symlinks.
(EOPNOTSUPP): Define if not defined.
* lib/unistd_.h (chown): Do not replace if REPLADE_CHOWN
is defined to 0.
(lchown): New decl.
* m4/lchown.m4 (gl_FUNC_LCHOWN): Require gl_UNISTD_H_DEFAULTS.
Do not check for lchown decl.
Set REPLACE_LCHOWN.
* m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Set GNULIB_LCHOWN,
REPLACE_LCHOWN.
* modules/chown: Make it clear it follows symlinks.
* modules/lchown: Make it clear it doesn't follow symlinks.
(Files): Remove lib/lchown.h
(Depends-on): Add unistd.
(configure.ac): Add gl_UNISTD_MODULE_INDICATOR([lchown]).
(Include): Include <unistd.h>, not "lchown.h".
* modules/unistd (unistd.h): Substitude GNULIB_LCHOWN and
REPLACE_LCHOWN.

12 files changed, 91 insertions, 61 deletions

diff --git a/ChangeLog b/ChangeLog
index 67a6d7a253..50180f0d74 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,30 @@
+2007-06-15  Paul Eggert  <eggert@cs.ucla.edu>
+
+	Revamp lchown so that it lives in unistd.h where it belongs.
+	* lib/lchown.h: Remove.
+	* lib/dirchownmod.c: Don't include lib/lchown.h.
+	* lib/fchownat.c: Likewise.
+	* lib/openat.c: Likewise.
+	* lib/lchown.c (REPLACE_CHOWN): Define to 0 if the system chown
+	does not follow symlinks.
+	(EOPNOTSUPP): Define if not defined.
+	* lib/unistd_.h (chown): Do not replace if REPLADE_CHOWN
+	is defined to 0.
+	(lchown): New decl.
+	* m4/lchown.m4 (gl_FUNC_LCHOWN): Require gl_UNISTD_H_DEFAULTS.
+	Do not check for lchown decl.
+	Set REPLACE_LCHOWN.
+	* m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Set GNULIB_LCHOWN,
+	REPLACE_LCHOWN.
+	* modules/chown: Make it clear it follows symlinks.
+	* modules/lchown: Make it clear it doesn't follow symlinks.
+	(Files): Remove lib/lchown.h
+	(Depends-on): Add unistd.
+	(configure.ac): Add gl_UNISTD_MODULE_INDICATOR([lchown]).
+	(Include): Include <unistd.h>, not "lchown.h".
+	* modules/unistd (unistd.h): Substitude GNULIB_LCHOWN and
+	REPLACE_LCHOWN.
+
 2007-06-15  Jim Meyering  <jim@meyering.net>
 
 	Change license (GPL to LGPL) of fsusage and dependents.
diff --git a/lib/dirchownmod.c b/lib/dirchownmod.c
index b3e9518086..25931e1f60 100644
--- a/lib/dirchownmod.c
+++ b/lib/dirchownmod.c
@@ -1,6 +1,6 @@
 /* Change the ownership and mode bits of a directory.
 
-   Copyright (C) 2006 Free Software Foundation, Inc.
+   Copyright (C) 2006, 2007 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
@@ -28,7 +28,6 @@
 #include <unistd.h>
 
 #include "lchmod.h"
-#include "lchown.h"
 #include "stat-macros.h"
 
 #ifndef HAVE_FCHMOD
diff --git a/lib/fchownat.c b/lib/fchownat.c
index 801c92a07e..6a6fe0f99b 100644
--- a/lib/fchownat.c
+++ b/lib/fchownat.c
@@ -29,7 +29,6 @@
 #include <unistd.h>
 
 #include "dirname.h" /* solely for definition of IS_ABSOLUTE_FILE_NAME */
-#include "lchown.h"
 #include "save-cwd.h"
 #include "openat-priv.h"
 
diff --git a/lib/lchown.c b/lib/lchown.c
index fa0826edb9..4ed4742116 100644
--- a/lib/lchown.c
+++ b/lib/lchown.c
@@ -1,6 +1,6 @@
 /* Provide a stub lchown function for systems that lack it.
 
-   Copyright (C) 1998, 1999, 2002, 2004, 2006 Free Software
+   Copyright (C) 1998, 1999, 2002, 2004, 2006, 2007 Free Software
    Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
@@ -21,10 +21,26 @@
 
 #include <config.h>
 
-#include "lchown.h"
+/* If the system chown does not follow symlinks, we don't want it
+   replaced by gnulib's chown, which does follow symlinks.  */
+#if CHOWN_MODIFIES_SYMLINK
+# define REPLACE_CHOWN 0
+#endif
+#include <unistd.h>
 
+#include <errno.h>
 #include <sys/stat.h>
 
+/* Some systems don't have EOPNOTSUPP.  */
+#ifndef EOPNOTSUPP
+# ifdef ENOTSUP
+#  define EOPNOTSUPP ENOTSUP
+# else
+/* Some systems don't have ENOTSUP either.  */
+#  define EOPNOTSUPP EINVAL
+# endif
+#endif
+
 /* Work just like chown, except when FILE is a symbolic link.
    In that case, set errno to EOPNOTSUPP and return -1.
    But if autoconf tests determined that chown modifies
diff --git a/lib/lchown.h b/lib/lchown.h
deleted file mode 100644
index 6816d1f129..0000000000
--- a/lib/lchown.h
+++ /dev/null
@@ -1,42 +0,0 @@
-/* Declare a replacement for lchown on hosts that lack it.
-
-   Copyright (C) 2006 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
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
-
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software Foundation,
-   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
-
-/* Written by Jim Meyering.  */
-
-#include <errno.h>
-#include <sys/types.h>
-#include <unistd.h>
-
-#if HAVE_DECL_LCHOWN
-# if ! HAVE_LCHOWN
-#  undef lchown
-#  define lchown rpl_chown
-# endif
-#else
-int lchown (char const *, uid_t, gid_t);
-#endif
-
-/* Some systems don't have EOPNOTSUPP.  */
-#ifndef EOPNOTSUPP
-# ifdef ENOTSUP
-#  define EOPNOTSUPP ENOTSUP
-# else
-/* Some systems don't have ENOTSUP either.  */
-#  define EOPNOTSUPP EINVAL
-# endif
-#endif
diff --git a/lib/openat.c b/lib/openat.c
index cd496540e7..25eedbb056 100644
--- a/lib/openat.c
+++ b/lib/openat.c
@@ -1,5 +1,5 @@
 /* provide a replacement openat function
-   Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc.
+   Copyright (C) 2004, 2005, 2006, 2007 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
@@ -26,7 +26,6 @@
 
 #include "dirname.h" /* solely for definition of IS_ABSOLUTE_FILE_NAME */
 #include "fcntl--.h"
-#include "lchown.h"
 #include "lstat.h"
 #include "openat-priv.h"
 #include "save-cwd.h"
diff --git a/lib/unistd_.h b/lib/unistd_.h
index f34bc66c17..2409005310 100644
--- a/lib/unistd_.h
+++ b/lib/unistd_.h
@@ -49,13 +49,18 @@ extern "C" {
 
 #if @GNULIB_CHOWN@
 # if @REPLACE_CHOWN@
+#  ifndef REPLACE_CHOWN
+#   define REPLACE_CHOWN 1
+#  endif
+#  if REPLACE_CHOWN
 /* Change the owner of FILE to UID (if UID is not -1) and the group of FILE
-   to GID (if GID is not -1).
+   to GID (if GID is not -1).  Follow symbolic links.
    Return 0 if successful, otherwise -1 and errno set.
    See the POSIX:2001 specification
    <http://www.opengroup.org/susv3xsh/chown.html>.  */
-#  define chown rpl_chown
+#   define chown rpl_chown
 extern int chown (const char *file, uid_t uid, gid_t gid);
+#  endif
 # endif
 #elif defined GNULIB_POSIXCHECK
 # undef chown
@@ -179,6 +184,25 @@ extern int getlogin_r (char *name, size_t size);
 #endif
 
 
+#if @GNULIB_LCHOWN@
+# if @REPLACE_LCHOWN@
+/* Change the owner of FILE to UID (if UID is not -1) and the group of FILE
+   to GID (if GID is not -1).  Do not follow symbolic links.
+   Return 0 if successful, otherwise -1 and errno set.
+   See the POSIX:2001 specification
+   <http://www.opengroup.org/susv3xsh/lchown.html>.  */
+#  define lchown rpl_lchown
+extern int lchown (char const *file, uid_t owner, gid_t group);
+# endif
+#elif defined GNULIB_POSIXCHECK
+# undef lchown
+# define lchown(f,u,g) \
+    (GL_LINK_WARNING ("lchown is unportable to pre-POSIX.1-2001 " \
+                      "systems - use gnulib module lchown for portability"), \
+     lchown (f, u, g))
+#endif
+
+
 #if @GNULIB_LSEEK@
 # if @REPLACE_LSEEK@
 /* Set the offset of FD relative to SEEK_SET, SEEK_CUR, or SEEK_END.
diff --git a/m4/lchown.m4 b/m4/lchown.m4
index a7b357297f..b719ed074c 100644
--- a/m4/lchown.m4
+++ b/m4/lchown.m4
@@ -1,7 +1,8 @@
-#serial 11
+#serial 12
+# Determine whether we need the lchown wrapper.
 
-dnl Copyright (C) 1998, 2001, 2003, 2004, 2005, 2006 Free Software
-dnl Foundation, Inc.
+dnl Copyright (C) 1998, 2001, 2003, 2004, 2005, 2006, 2007 Free
+dnl Software Foundation, Inc.
 
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -12,8 +13,10 @@ dnl Provide lchown on systems that lack it.
 
 AC_DEFUN([gl_FUNC_LCHOWN],
 [
-  AC_REQUIRE([AC_TYPE_UID_T])
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
   AC_REQUIRE([gl_FUNC_CHOWN])
-  AC_CHECK_DECLS_ONCE([lchown])
   AC_REPLACE_FUNCS(lchown)
+  if test $ac_cv_func_lchown = no; then
+    REPLACE_LCHOWN=1
+  fi
 ])
diff --git a/m4/unistd_h.m4 b/m4/unistd_h.m4
index 60dd73081a..90e1eaa32d 100644
--- a/m4/unistd_h.m4
+++ b/m4/unistd_h.m4
@@ -1,4 +1,4 @@
-# unistd_h.m4 serial 7
+# unistd_h.m4 serial 8
 dnl Copyright (C) 2006-2007 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -39,6 +39,7 @@ AC_DEFUN([gl_UNISTD_H_DEFAULTS],
   GNULIB_FTRUNCATE=0;     AC_SUBST([GNULIB_FTRUNCATE])
   GNULIB_GETCWD=0;        AC_SUBST([GNULIB_GETCWD])
   GNULIB_GETLOGIN_R=0;    AC_SUBST([GNULIB_GETLOGIN_R])
+  GNULIB_LCHOWN=0;        AC_SUBST([GNULIB_LCHOWN])
   GNULIB_LSEEK=0;         AC_SUBST([GNULIB_LSEEK])
   GNULIB_READLINK=0;      AC_SUBST([GNULIB_READLINK])
   GNULIB_SLEEP=0;         AC_SUBST([GNULIB_SLEEP])
@@ -51,5 +52,6 @@ AC_DEFUN([gl_UNISTD_H_DEFAULTS],
   REPLACE_CHOWN=0;        AC_SUBST([REPLACE_CHOWN])
   REPLACE_FCHDIR=0;       AC_SUBST([REPLACE_FCHDIR])
   REPLACE_GETCWD=0;       AC_SUBST([REPLACE_GETCWD])
+  REPLACE_LCHOWN=0;       AC_SUBST([REPLACE_LCHOWN])
   REPLACE_LSEEK=0;        AC_SUBST([REPLACE_LSEEK])
 ])
diff --git a/modules/chown b/modules/chown
index a8ac9531bb..9e479a5090 100644
--- a/modules/chown
+++ b/modules/chown
@@ -1,5 +1,5 @@
 Description:
-chown() function: change ownership of a file.
+chown() function: change ownership of a file, following symlinks.
 
 Files:
 lib/chown.c
diff --git a/modules/lchown b/modules/lchown
index 3607c079c5..e011e2bddb 100644
--- a/modules/lchown
+++ b/modules/lchown
@@ -1,22 +1,23 @@
 Description:
-lchown() function: change ownership of a file.
+lchown() function: change ownership of a file, without following symlinks.
 
 Files:
-lib/lchown.h
 lib/lchown.c
 m4/lchown.m4
 
 Depends-on:
 chown
 sys_stat
+unistd
 
 configure.ac:
 gl_FUNC_LCHOWN
+gl_UNISTD_MODULE_INDICATOR([lchown])
 
 Makefile.am:
 
 Include:
-"lchown.h"
+<unistd.h>
 
 License:
 GPL
diff --git a/modules/unistd b/modules/unistd
index 6bf946061b..3529b03c57 100644
--- a/modules/unistd
+++ b/modules/unistd
@@ -29,6 +29,7 @@ unistd.h: unistd_.h
 	      -e 's|@''GNULIB_FTRUNCATE''@|$(GNULIB_FTRUNCATE)|g' \
 	      -e 's|@''GNULIB_GETCWD''@|$(GNULIB_GETCWD)|g' \
 	      -e 's|@''GNULIB_GETLOGIN_R''@|$(GNULIB_GETLOGIN_R)|g' \
+	      -e 's|@''GNULIB_LCHOWN''@|$(GNULIB_LCHOWN)|g' \
 	      -e 's|@''GNULIB_LSEEK''@|$(GNULIB_LSEEK)|g' \
 	      -e 's|@''GNULIB_READLINK''@|$(GNULIB_READLINK)|g' \
 	      -e 's|@''GNULIB_SLEEP''@|$(GNULIB_SLEEP)|g' \
@@ -40,6 +41,7 @@ unistd.h: unistd_.h
 	      -e 's|@''REPLACE_CHOWN''@|$(REPLACE_CHOWN)|g' \
 	      -e 's|@''REPLACE_FCHDIR''@|$(REPLACE_FCHDIR)|g' \
 	      -e 's|@''REPLACE_GETCWD''@|$(REPLACE_GETCWD)|g' \
+	      -e 's|@''REPLACE_LCHOWN''@|$(REPLACE_LCHOWN)|g' \
 	      -e 's|@''REPLACE_LSEEK''@|$(REPLACE_LSEEK)|g' \
 	      < $(srcdir)/unistd_.h; \
 	} > $@-t