Fixed #19882 -- Smarter tokenizing of {% for %} tag arguments.

django/template/defaulttags.py

@@ -746,7 +746,7 @@ def do_for(parser, token):
         ==========================  ================================================
 
     """
-    bits = token.contents.split()
+    bits = token.split_contents()
     if len(bits) < 4:
         raise TemplateSyntaxError("'for' statements should have at least four"
                                   " words: %s" % token.contents)

tests/regressiontests/templates/tests.py

@@ -833,6 +833,8 @@ class Templates(TestCase):
             'for-tag-empty01': ("{% for val in values %}{{ val }}{% empty %}empty text{% endfor %}", {"values": [1, 2, 3]}, "123"),
             'for-tag-empty02': ("{% for val in values %}{{ val }}{% empty %}values array empty{% endfor %}", {"values": []}, "values array empty"),
             'for-tag-empty03': ("{% for val in values %}{{ val }}{% empty %}values array not found{% endfor %}", {}, "values array not found"),
+            # Ticket 19882
+            'for-tag-filter-ws': ("{% for x in ''|add:'a b c' %}{{ x }}{% endfor %}", {}, 'a b c'),
 
             ### IF TAG ################################################################
             'if-tag01': ("{% if foo %}yes{% else %}no{% endif %}", {"foo": True}, "yes"),