Fixed a translation error caused by looping over empty recursive loops.

--HG--
branch : trunk
diff --git a/tests/test_forloop.py b/tests/test_forloop.py
index 0c307ec..f5e4996 100644
--- a/tests/test_forloop.py
+++ b/tests/test_forloop.py
@@ -153,3 +153,10 @@
     t = env.from_string('{% for x in seq %}{% for y in seq %}'
                         '{{ loop.first }}{% endfor %}{% endfor %}')
     assert t.render(seq='ab') == 'TrueFalseTrueFalse'
+
+
+def test_recursive_empty_loop_iter(env):
+    t = env.from_string('''
+    {%- for item in foo recursive -%}{%- endfor -%}
+    ''')
+    assert t.render(dict(foo=[])) == ''