[file_utils] unln: sync after copy

file_utils/unln.py

@@ -129,6 +129,11 @@ for filename in sys.argv[1:]:
     verbose("Copying to temporary file", quote(tmpfilename), end="... ")
     shutil.copy2(filename, tmpfilename) # cp -p
 
+    # Try to sync if we are running Python >= 3.3
+    if sys.version_info.minor >= 3:
+        verbose("Syncing", end="... ")
+        os.sync()
+
     # Rename the temporary file with the original file name
     verbose("Moving back {} to {}...".format(
             quote(tmpfilename), quote(filename)))