--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,29 @@
+2008-10-09  Paolo Bonzini  <bonzini@gnu.org>
+            Bruno Haible  <bruno@clisp.org>
+
+	Combine the two replacements of 'close'.
+	* lib/sys_socket.in.h (close): Define to a reminder to include <unistd.h>.
+	(_gl_close_fd_maybe_socket): New declaration.
+	(HAVE__GL_CLOSE_FD_MAYBE_SOCKET): New macro.
+	* lib/winsock.c (close): Remove undefinition.
+	(_gl_close_fd_maybe_socket): Renamed from rpl_close. Define only when
+	needed for the gnulib module 'close'.
+	* lib/unistd.in.h (close): If the gnulib module 'close' is not used,
+	define to an error symbol or to a warning, if suitable.
+	* lib/close.c: Include <sys/socket.h>.
+	(rpl_close): Invoke _gl_close_fd_maybe_socket when gnulib defines it.
+	* m4/sys_socket_h.m4 (gl_PREREQ_SYS_H_WINSOCK2): Set also
+	UNISTD_H_HAVE_WINSOCK2_H.
+	(gl_SYS_SOCKET_H_DEFAULTS): Require gl_UNISTD_H_DEFAULTS.
+	* m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Initialize
+	UNISTD_H_HAVE_WINSOCK2_H.
+	* modules/sys_socket (Files): Add m4/unistd_h.m4.
+	(configure.ac): Set a module indicator.
+	(Makefile.am): Substitute GNULIB_CLOSE.
+	* modules/unistd (Makefile.am): Substitute UNISTD_H_HAVE_WINSOCK2_H.
+	* modules/poll-tests (Depends-on): Add close.
+	* modules/select-tests (Depends-on): Likewise.
+
 2008-10-09  Paolo Bonzini  <bonzini@gnu.org>
             Bruno Haible  <bruno@clisp.org>
 

--- a/lib/close.c
+++ b/lib/close.c
@@ -19,6 +19,10 @@
 /* Specification.  */
 #include <unistd.h>
 
+#if GNULIB_SYS_SOCKET
+# include <sys/socket.h>
+#endif
+
 
 /* Override close() to call into other gnulib modules.  */
 
@@ -26,7 +30,11 @@
 rpl_close (int fd)
 #undef close
 {
+#if HAVE__GL_CLOSE_FD_MAYBE_SOCKET
+  int retval = _gl_close_fd_maybe_socket (fd);
+#else
   int retval = close (fd);
+#endif
 
 #ifdef FCHDIR_REPLACEMENT
   if (retval >= 0)

--- a/lib/sys_socket.in.h
+++ b/lib/sys_socket.in.h
@@ -138,10 +138,9 @@
 
 /* Wrap everything else to use libc file descriptors for sockets.  */
 
-# if @HAVE_WINSOCK2_H@
+# if @HAVE_WINSOCK2_H@ && !defined _GL_UNISTD_H
 #  undef close
-#  define close			rpl_close
-extern int rpl_close(int);
+#  define close close_used_without_including_unistd_h
 # endif
 
 # if @GNULIB_SOCKET@
@@ -376,6 +375,12 @@
 #  define select		select_used_without_including_sys_select_h
 # endif
 
+# if @GNULIB_CLOSE@ && @HAVE_WINSOCK2_H@
+/* gnulib internal function.  */
+#  define HAVE__GL_CLOSE_FD_MAYBE_SOCKET 1
+extern int _gl_close_fd_maybe_socket (int fd);
+# endif
+
 # ifdef __cplusplus
 }
 # endif

--- a/lib/unistd.in.h
+++ b/lib/unistd.in.h
@@ -82,6 +82,15 @@
 #  define close rpl_close
 extern int close (int);
 # endif
+#elif @UNISTD_H_HAVE_WINSOCK2_H@
+# undef close
+# define close close_used_without_requesting_gnulib_module_close
+#elif defined GNULIB_POSIXCHECK
+# undef close
+# define close(f) \
+    (GL_LINK_WARNING ("close does not portably work on sockets - " \
+                      "use gnulib module close for portability"), \
+     close (f))
 #endif
 
 

--- a/lib/winsock.c
+++ b/lib/winsock.c
@@ -25,7 +25,6 @@
 #include <io.h>
 #include <sys/socket.h>
 
-#undef close
 #undef socket
 #undef connect
 #undef accept
@@ -44,10 +43,11 @@
 # define SOCKET_TO_FD(fh)   (_open_osfhandle ((long) (fh), O_RDWR | O_BINARY))
 
 
-/* Wrappers for libc functions.  */
+/* Hook for gnulib module close.  */
 
+#if HAVE__GL_CLOSE_FD_MAYBE_SOCKET
 int
-rpl_close (int fd)
+_gl_close_fd_maybe_socket (int fd)
 {
   SOCKET sock = FD_TO_SOCKET (fd);
   WSANETWORKEVENTS ev;
@@ -67,6 +67,7 @@
   else
     return _close (fd);
 }
+#endif
 
 
 /* Wrappers for WinSock functions.  */

--- a/m4/sys_socket_h.m4
+++ b/m4/sys_socket_h.m4
@@ -1,4 +1,4 @@
-# sys_socket_h.m4 serial 8
+# sys_socket_h.m4 serial 9
 dnl Copyright (C) 2005-2008 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -71,6 +71,7 @@
 # Sets and substitutes HAVE_WINSOCK2_H.
 AC_DEFUN([gl_PREREQ_SYS_H_WINSOCK2],
 [
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
   AC_CHECK_HEADERS_ONCE([sys/socket.h])
   if test $ac_cv_header_sys_socket_h != yes; then
     dnl We cannot use AC_CHECK_HEADERS_ONCE here, because that would make
@@ -81,6 +82,7 @@
   fi
   if test "$ac_cv_header_winsock2_h" = yes; then
     HAVE_WINSOCK2_H=1
+    UNISTD_H_HAVE_WINSOCK2_H=1
   else
     HAVE_WINSOCK2_H=0
   fi
@@ -97,6 +99,7 @@
 
 AC_DEFUN([gl_SYS_SOCKET_H_DEFAULTS],
 [
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) dnl for GNULIB_CLOSE
   GNULIB_SOCKET=0;      AC_SUBST([GNULIB_SOCKET])
   GNULIB_CONNECT=0;     AC_SUBST([GNULIB_CONNECT])
   GNULIB_ACCEPT=0;      AC_SUBST([GNULIB_ACCEPT])

--- a/m4/unistd_h.m4
+++ b/m4/unistd_h.m4
@@ -69,4 +69,5 @@
   REPLACE_LCHOWN=0;       AC_SUBST([REPLACE_LCHOWN])
   REPLACE_LSEEK=0;        AC_SUBST([REPLACE_LSEEK])
   REPLACE_WRITE=0;        AC_SUBST([REPLACE_WRITE])
+  UNISTD_H_HAVE_WINSOCK2_H=0; AC_SUBST([UNISTD_H_HAVE_WINSOCK2_H])
 ])

--- a/modules/poll-tests
+++ b/modules/poll-tests
@@ -17,6 +17,7 @@
 listen
 connect
 accept
+close
 
 configure.ac:
 AC_CHECK_HEADERS_ONCE([unistd.h sys/wait.h])

--- a/modules/select-tests
+++ b/modules/select-tests
@@ -16,6 +16,7 @@
 listen
 connect
 accept
+close
 
 configure.ac:
 

--- a/modules/sys_socket
+++ b/modules/sys_socket
@@ -6,6 +6,7 @@
 lib/winsock.c
 m4/sys_socket_h.m4
 m4/sockpfaf.m4
+m4/unistd_h.m4
 
 Depends-on:
 include_next
@@ -14,6 +15,7 @@
 
 configure.ac:
 gl_HEADER_SYS_SOCKET
+gl_MODULE_INDICATOR([sys_socket])
 AC_PROG_MKDIR_P
 
 Makefile.am:
@@ -28,6 +30,7 @@
 	      -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
 	      -e 's|@''NEXT_SYS_SOCKET_H''@|$(NEXT_SYS_SOCKET_H)|g' \
 	      -e 's|@''HAVE_SYS_SOCKET_H''@|$(HAVE_SYS_SOCKET_H)|g' \
+	      -e 's|@''GNULIB_CLOSE''@|$(GNULIB_CLOSE)|g' \
 	      -e 's|@''GNULIB_SOCKET''@|$(GNULIB_SOCKET)|g' \
 	      -e 's|@''GNULIB_CONNECT''@|$(GNULIB_CONNECT)|g' \
 	      -e 's|@''GNULIB_ACCEPT''@|$(GNULIB_ACCEPT)|g' \

--- a/modules/unistd
+++ b/modules/unistd
@@ -60,6 +60,7 @@
 	      -e 's|@''REPLACE_LCHOWN''@|$(REPLACE_LCHOWN)|g' \
 	      -e 's|@''REPLACE_LSEEK''@|$(REPLACE_LSEEK)|g' \
 	      -e 's|@''REPLACE_WRITE''@|$(REPLACE_WRITE)|g' \
+	      -e 's|@''UNISTD_H_HAVE_WINSOCK2_H''@|$(UNISTD_H_HAVE_WINSOCK2_H)|g' \
 	      -e '/definition of GL_LINK_WARNING/r $(LINK_WARNING_H)' \
 	      < $(srcdir)/unistd.in.h; \
 	} > $@-t