Fixed #11012: don't needless convert cache values to unicode.

This means you can now successfully store binary blogs, such as compressed data,
in the cache.

Thanks to Matt Croydon for the final patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12637 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/core/cache/backends/memcached.py

@@ -43,15 +43,9 @@ def get(self, key, default=None):
         val = self._cache.get(smart_str(key))
         if val is None:
             return default
-        else:
-            if isinstance(val, basestring):
-                return smart_unicode(val)
-            else:
-                return val
+        return val
 
     def set(self, key, value, timeout=0):
-        if isinstance(value, unicode):
-            value = value.encode('utf-8')
         self._cache.set(smart_str(key), value, self._get_memcache_timeout(timeout))
 
     def delete(self, key):

tests/regressiontests/cache/tests.py

@@ -295,6 +295,16 @@ def test_unicode(self):
             self.cache.set(key, value)
             self.assertEqual(self.cache.get(key), value)
 
+    def test_binary_string(self):
+        # Binary strings should be cachable
+        from zlib import compress, decompress
+        value = 'value_to_be_compressed'
+        compressed_value = compress(value)
+        self.cache.set('binary1', compressed_value)
+        compressed_result = self.cache.get('binary1')
+        self.assertEqual(compressed_value, compressed_result)
+        self.assertEqual(value, decompress(compressed_result))
+
     def test_set_many(self):
         # Multiple keys can be set using set_many
         self.cache.set_many({"key1": "spam", "key2": "eggs"})