From 5650098a61c5a319dcd21dcf6a94a781691c93a8 Mon Sep 17 00:00:00 2001
From: Mark Williams <markrwilliams@gmail.com>
Date: Sat, 11 Apr 2015 01:49:57 -0700
Subject: [PATCH] fixes #21 - self.root was not being correctly updated, so the
 list never rotated out entries!

this has a very simple test to demonstrate the issue is closed.  more tests are needed.
---
 boltons/cacheutils.py | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/boltons/cacheutils.py b/boltons/cacheutils.py
index 72b71cc..84d23d5 100644
--- a/boltons/cacheutils.py
+++ b/boltons/cacheutils.py
@@ -133,7 +133,7 @@ class LRU(dict):
                 oldroot[KEY] = key
                 oldroot[VALUE] = value
                 # prevent ref counts going to zero during update
-                root = oldroot[NEXT]
+                self.root = root = oldroot[NEXT]
                 oldkey, oldresult = root[KEY], root[VALUE]
                 root[KEY] = root[VALUE] = None
                 # Now update the cache dictionary.
@@ -433,8 +433,15 @@ def cached(cache, typed=False):
     return cached_func_decorator
 
 
+def test_21():
+    cache = LRU(max_size=3)
+    for i in xrange(4):
+        cache[i] = i
+
 
 if __name__ == '__main__':
+    test_21()
+
     def _test_lri():
         import string
         bc = LRI(10, on_miss=lambda k: k.upper())