[1.2.0] Unit test housekeeping:

- HTMLPurifier_Context doesn't throw a variable reference error if you attempt to retrieve a non-existent variable
. Cleaned up test-cases to remove unnecessary swallowErrors()

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@525 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/Context.php

@@ -34,7 +34,8 @@ class HTMLPurifier_Context
         if (!isset($this->_storage[$name])) {
             trigger_error('Attempted to retrieve non-existent variable',
                           E_USER_ERROR);
-            return;
+            $var = null; // so we can return by reference
+            return $var;
         }
         return $this->_storage[$name];
     }