commit 6870daf7ef98579c73473fb8b8852abf6ce7f1f8
Author: Neil Wilson <neil@aldur.co.uk>
Date:   Wed Jul 4 16:58:53 2012 +0100

    utils.py: Add guard for blank responses to get-instance-metadata

diff --git a/boto/utils.py b/boto/utils.py
index 860a26c..d71eb7a 100644
--- a/boto/utils.py
+++ b/boto/utils.py
@@ -251,7 +251,7 @@ class LazyLoadMetadata(dict):
             val = boto.utils.retry_url(self._url + urllib.quote(resource,
                                                                 safe="/:"),
                                        num_retries=self._num_retries)
-            if val[0] == '{':
+            if val and val[0] == '{':
                 val = json.loads(val)
             else:
                 p = val.find('\n')