From 183111be6505ba0a702db448b05a1a5fd0538c9c 2011-07-04 22:44:51
From: Thomas Kluyver <takowl@gmail.com>
Date: 2011-07-04 22:44:51
Subject: [PATCH] When moving old config files, don't clobber files we've previously moved.

---

diff --git a/IPython/utils/path.py b/IPython/utils/path.py
index 3c8ee4e..f715a14 100644
--- a/IPython/utils/path.py
+++ b/IPython/utils/path.py
@@ -435,6 +435,10 @@ def check_for_old_config(ipython_dir=None):
                 os.unlink(f)
             else:
                 oldf = f+'.old'
+                i = 0
+                while os.path.exists(oldf):
+                    oldf = f+'.old.%i'%i
+                    i += 1
                 os.rename(f, oldf)
                 warn.warn("Renamed old IPython config file '%s' to '%s'." % (f, oldf))
                 warned = True