From 9a4bbb771e3638f1c53079e89fcd7e2a6ac6b51a Mon Sep 17 00:00:00 2001
From: Andrew Resch <andrewresch@gmail.com>
Date: Sun, 8 Mar 2009 02:33:12 +0000
Subject: [PATCH] Make a backup of config files before overwriting and make
 sure the file is fsync'd without error

---
 deluge/config.py | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/deluge/config.py b/deluge/config.py
index 52b22c6a4..510dbce08 100644
--- a/deluge/config.py
+++ b/deluge/config.py
@@ -270,13 +270,26 @@ class Config(object):
 
         self.__save_timer = None
 
+        # Save the new config and make sure it's written to disk
         try:
             log.debug("Saving new config file %s", filename + ".new")
-            json.dump(self.__config, open(filename + ".new", "w"), indent=2)
+            f = open(filename + ".new", "w")
+            json.dump(self.__config, f, indent=2)
+            f.flush()
+            os.fsync(f.fileno())
+            f.close()
         except Exception, e:
             log.error("Error writing new config file: %s", e)
             return
 
+        # Make a backup of the old config
+        try:
+            log.debug("Backing up old config file to %s~", filename)
+            shutil.move(filename, filename + "~")
+        except Exception, e:
+            log.error("Error backing up old config..")
+            return
+
         # The new config file has been written successfully, so let's move it over
         # the existing one.
         try: