Fix lifetimes passed as string "false" from layout XML

Cm/Cache/Backend/Redis.php

@@ -477,6 +477,25 @@ public function test($id)
         return ($mtime ? $mtime : FALSE);
     }
 
+    /**
+     * Get the life time
+     *
+     * if $specificLifetime is not false, the given specific life time is used
+     * else, the global lifetime is used
+     *
+     * @param  int $specificLifetime
+     * @return int Cache life time
+     */
+    public function getLifetime($specificLifetime)
+    {
+        // Lifetimes set via Layout XMLs get parsed as string so bool(false) becomes string("false")
+        if ($specificLifetime === 'false') {
+            $specificLifetime = false;
+        }
+
+        return parent::getLifetime($specificLifetime);
+    }
+
     /**
      * Save some string datas into a cache record
      *