diff --git a/CHANGELOG b/CHANGELOG
index 8feae8baf..c541bd705 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -13,8 +13,17 @@
  * improved the performance of the filesystem loader
  * removed features that were deprecated in 1.x
 
-* 1.22.3 (2015-XX-XX)
+* 1.22.4 (2015-XX-XX)
 
+ * n/a
+
+* 1.22.3 (2015-10-13)
+
+ * fixed regression when using null as a cache strategy
+ * improved performance when checking template freshness
+ * fixed warnings when loaded templates do not exist
+ * fixed template class name generation to prevent possible collisions
+ * fixed logic for custom escapers to call them even on integers and null values
  * changed template cache names to take into account the Twig C extension
 
 * 1.22.2 (2015-09-22)
diff --git a/doc/templates.rst b/doc/templates.rst
index d90749cfa..0542c573a 100644
--- a/doc/templates.rst
+++ b/doc/templates.rst
@@ -758,15 +758,27 @@ tests.
 Other Operators
 ~~~~~~~~~~~~~~~
 
-The following operators are very useful but don't fit into any of the other
-categories:
-
-* ``..``: Creates a sequence based on the operand before and after the
-  operator (this is just syntactic sugar for the :doc:`range<functions/range>`
-  function).
+The following operators don't fit into any of the other categories:
 
 * ``|``: Applies a filter.
 
+* ``..``: Creates a sequence based on the operand before and after the operator
+  (this is just syntactic sugar for the :doc:`range<functions/range>` function):
+
+  .. code-block:: jinja
+
+      {{ 1..5 }}
+
+      {# equivalent to #}
+      {{ range(1, 5) }}
+
+  Note that you must use parentheses when combining it with the filter operator
+  due to the :ref:`operator precedence rules <twig-expressions>`:
+
+  .. code-block:: jinja
+
+      (1..5)|join(', ')
+
 * ``~``: Converts all operands into strings and concatenates them. ``{{ "Hello
   " ~ name ~ "!" }}`` would return (assuming ``name`` is ``'John'``) ``Hello
   John!``.
diff --git a/lib/Twig/Cache/Filesystem.php b/lib/Twig/Cache/Filesystem.php
index 463104463..2c2182a82 100644
--- a/lib/Twig/Cache/Filesystem.php
+++ b/lib/Twig/Cache/Filesystem.php
@@ -87,6 +87,10 @@ class Twig_Cache_Filesystem implements Twig_CacheInterface
      */
     public function getTimestamp($key)
     {
+        if (!file_exists($key)) {
+            return 0;
+        }
+
         return (int) @filemtime($key);
     }
 }
diff --git a/lib/Twig/Environment.php b/lib/Twig/Environment.php
index fd026f217..e5b556282 100644
--- a/lib/Twig/Environment.php
+++ b/lib/Twig/Environment.php
@@ -45,6 +45,7 @@ class Twig_Environment
     private $filterCallbacks = array();
     private $staging;
     private $originalCache;
+    private $lastModifiedExtension = 0;
 
     /**
      * Constructor.
@@ -238,6 +239,10 @@ class Twig_Environment
         } elseif (false === $cache) {
             $this->originalCache = $cache;
             $this->cache = new Twig_Cache_Null();
+        } elseif (null === $cache) {
+            @trigger_error('Using "null" as the cache strategy is deprecated and will be removed in Twig 2.0.', E_USER_DEPRECATED);
+            $this->originalCache = false;
+            $this->cache = new Twig_Cache_Null();
         } elseif ($cache instanceof Twig_CacheInterface) {
             $this->originalCache = $this->cache = $cache;
         } else {
@@ -386,14 +391,7 @@ class Twig_Environment
      */
     public function isTemplateFresh($name, $time)
     {
-        foreach ($this->extensions as $extension) {
-            $r = new ReflectionObject($extension);
-            if (filemtime($r->getFileName()) > $time) {
-                return false;
-            }
-        }
-
-        return $this->getLoader()->isFresh($name, $time);
+        return $this->lastModifiedExtension <= $time && $this->getLoader()->isFresh($name, $time);
     }
 
     /**
@@ -665,6 +663,11 @@ class Twig_Environment
             throw new LogicException(sprintf('Unable to register extension "%s" as extensions have already been initialized.', $extension->getName()));
         }
 
+        $r = new ReflectionObject($extension);
+        if (($extensionTime = filemtime($r->getFileName())) > $this->lastModifiedExtension) {
+            $this->lastModifiedExtension = $extensionTime;
+        }
+
         $this->extensions[$extension->getName()] = $extension;
     }