2 files changed, 8 insertions, 3 deletions
diff --git a/ChangeLog b/ChangeLog
index 34db53450b..dbecb72df2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Jun  2 12:33:09 2011  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* io.c (io_flush, rb_io_flush): need to fsync() when ruby calls internal
+	  flush. [ruby-core:36670] [Bug #4813]
+
 Thu Jun  2 07:56:24 2011  Hidetoshi NAGAI  <nagai@ai.kyutech.ac.jp>
 
 	* ext/tk/tcltklib.c: reduce CPU power required by an eventloop.
diff --git a/io.c b/io.c
index 0025f86073..e8f44dcd43 100644
--- a/io.c
+++ b/io.c
@@ -682,6 +682,9 @@ io_fflush(rb_io_t *fptr)
 	    return -1;
         rb_io_check_closed(fptr);
     }
+#ifdef _WIN32
+    fsync(fptr->fd);
+#endif
     return 0;
 }
 
@@ -1054,9 +1057,6 @@ rb_io_flush(VALUE io)
     if (fptr->mode & FMODE_WRITABLE) {
         if (io_fflush(fptr) < 0)
             rb_sys_fail(0);
-#ifdef _WIN32
-	fsync(fptr->fd);
-#endif
     }
     if (fptr->mode & FMODE_READABLE) {
         io_unread(fptr);