File synchronization fixes.

* admin/CPP-DEFINES (BSD_SYSTEM, HAVE_FSYNC): Remove.
* admin/merge-gnulib (GNULIB_MODULES): Add fsync, fdatasync.
* configure.ac (BSD_SYSTEM, BSD_SYSTEM_AHB): Remove; no longer needed.
(fsync): Remove check; now done by gnulib.
* lib/fdatasync.c, lib/fsync.c, m4/fdatasync.m4, m4/fsync.m4:
New files, from gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* lib-src/Makefile.in (LIB_FDATASYNC): New macro.
(emacsclient${EXEEXT}): Use it.
* lib-src/emacsclient.c (main): Use fdatasync, not fsync, since we don't
care about metadata.  Keep trying if interrupted.
* lib-src/movemail.c (main, popmail): Don't worry about BSD_SYSTEM, since
fsync is available everywhere (or there is a substitute).  Don't
report an error if fsync returns EINVAL.
* nt/inc/ms-w32.h (fdatasync): New macro, suggested by Eli Zaretskii.
* src/Makefile.in (LIB_FDATASYNC): New macro.
(LIBES): Use it.
* src/conf_post.h (BSD_SYSTEM, BSD_SYSTEM_AHB): Remove; no longer needed.
* src/fileio.c (Fwrite_region, write_region_inhibit_fsync):
Don't worry about HAVE_FSYNC, since a substitute fsync is
available if the system lacks one.
(Fwrite_regin): Retry fsync if interrupted.

Fixes: debbugs:13944

3 files changed, 66 insertions, 0 deletions

diff --git a/m4/fdatasync.m4 b/m4/fdatasync.m4
new file mode 100644
index 00000000000..551c0d9ff4e
--- /dev/null
+++ b/m4/fdatasync.m4
@@ -0,0 +1,32 @@
+# fdatasync.m4 serial 4
+dnl Copyright (C) 2008-2013 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_FDATASYNC],
+[
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+
+  dnl Using AC_CHECK_FUNCS_ONCE would break our subsequent AC_SEARCH_LIBS
+  AC_CHECK_DECLS_ONCE([fdatasync])
+  LIB_FDATASYNC=
+  AC_SUBST([LIB_FDATASYNC])
+
+  if test $ac_cv_have_decl_fdatasync = no; then
+    HAVE_DECL_FDATASYNC=0
+    dnl Mac OS X 10.7 has fdatasync but does not declare it.
+    AC_CHECK_FUNCS([fdatasync])
+    if test $ac_cv_func_fdatasync = no; then
+      HAVE_FDATASYNC=0
+    fi
+  else
+    dnl Solaris <= 2.6 has fdatasync() in libposix4.
+    dnl Solaris 7..10 has it in librt.
+    gl_saved_libs=$LIBS
+    AC_SEARCH_LIBS([fdatasync], [rt posix4],
+                   [test "$ac_cv_search_fdatasync" = "none required" ||
+                    LIB_FDATASYNC=$ac_cv_search_fdatasync])
+    LIBS=$gl_saved_libs
+  fi
+])
diff --git a/m4/fsync.m4 b/m4/fsync.m4
new file mode 100644
index 00000000000..43f51528d6b
--- /dev/null
+++ b/m4/fsync.m4
@@ -0,0 +1,17 @@
+# fsync.m4 serial 2
+dnl Copyright (C) 2008-2013 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_FSYNC],
+[
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_CHECK_FUNCS_ONCE([fsync])
+  if test $ac_cv_func_fsync = no; then
+    HAVE_FSYNC=0
+  fi
+])
+
+# Prerequisites of lib/fsync.c.
+AC_DEFUN([gl_PREREQ_FSYNC], [:])
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index 6c3012d827f..d304f10b76f 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -63,10 +63,12 @@ AC_DEFUN([gl_EARLY],
   # Code from module extern-inline:
   # Code from module faccessat:
   # Code from module fcntl-h:
+  # Code from module fdatasync:
   # Code from module fdopendir:
   # Code from module filemode:
   # Code from module fpending:
   # Code from module fstatat:
+  # Code from module fsync:
   # Code from module getgroups:
   # Code from module getloadavg:
   # Code from module getopt-gnu:
@@ -187,6 +189,11 @@ AC_DEFUN([gl_INIT],
   gl_MODULE_INDICATOR([faccessat])
   gl_UNISTD_MODULE_INDICATOR([faccessat])
   gl_FCNTL_H
+  gl_FUNC_FDATASYNC
+  if test $HAVE_FDATASYNC = 0; then
+    AC_LIBOBJ([fdatasync])
+  fi
+  gl_UNISTD_MODULE_INDICATOR([fdatasync])
   gl_FUNC_FDOPENDIR
   if test $HAVE_FDOPENDIR = 0 || test $REPLACE_FDOPENDIR = 1; then
     AC_LIBOBJ([fdopendir])
@@ -204,6 +211,12 @@ AC_DEFUN([gl_INIT],
     AC_LIBOBJ([fstatat])
   fi
   gl_SYS_STAT_MODULE_INDICATOR([fstatat])
+  gl_FUNC_FSYNC
+  if test $HAVE_FSYNC = 0; then
+    AC_LIBOBJ([fsync])
+    gl_PREREQ_FSYNC
+  fi
+  gl_UNISTD_MODULE_INDICATOR([fsync])
   gl_GETLOADAVG
   if test $HAVE_GETLOADAVG = 0; then
     AC_LIBOBJ([getloadavg])
@@ -743,12 +756,14 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/execinfo.in.h
   lib/faccessat.c
   lib/fcntl.in.h
+  lib/fdatasync.c
   lib/fdopendir.c
   lib/filemode.c
   lib/filemode.h
   lib/fpending.c
   lib/fpending.h
   lib/fstatat.c
+  lib/fsync.c
   lib/ftoastr.c
   lib/ftoastr.h
   lib/getgroups.c
@@ -842,10 +857,12 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/faccessat.m4
   m4/fcntl-o.m4
   m4/fcntl_h.m4
+  m4/fdatasync.m4
   m4/fdopendir.m4
   m4/filemode.m4
   m4/fpending.m4
   m4/fstatat.m4
+  m4/fsync.m4
   m4/getgroups.m4
   m4/getloadavg.m4
   m4/getopt.m4