Fixed #26478 -- Made {% for %} reject invalid unpacking vars with quotes or vertical bars.

django/template/defaulttags.py

@@ -17,10 +17,10 @@ from django.utils.safestring import mark_safe
 
 from .base import (
     BLOCK_TAG_END, BLOCK_TAG_START, COMMENT_TAG_END, COMMENT_TAG_START,
-    SINGLE_BRACE_END, SINGLE_BRACE_START, VARIABLE_ATTRIBUTE_SEPARATOR,
-    VARIABLE_TAG_END, VARIABLE_TAG_START, Context, Node, NodeList,
-    TemplateSyntaxError, VariableDoesNotExist, kwarg_re,
-    render_value_in_context, token_kwargs,
+    FILTER_SEPARATOR, SINGLE_BRACE_END, SINGLE_BRACE_START,
+    VARIABLE_ATTRIBUTE_SEPARATOR, VARIABLE_TAG_END, VARIABLE_TAG_START,
+    Context, Node, NodeList, TemplateSyntaxError, VariableDoesNotExist,
+    kwarg_re, render_value_in_context, token_kwargs,
 )
 from .defaultfilters import date
 from .library import Library
@@ -816,9 +816,10 @@ def do_for(parser, token):
         raise TemplateSyntaxError("'for' statements should use the format"
                                   " 'for x in y': %s" % token.contents)
 
+    invalid_chars = frozenset((' ', '"', "'", FILTER_SEPARATOR))
     loopvars = re.split(r' *, *', ' '.join(bits[1:in_index]))
     for var in loopvars:
-        if not var or ' ' in var:
+        if not var or not invalid_chars.isdisjoint(var):
             raise TemplateSyntaxError("'for' tag received an invalid argument:"
                                       " %s" % token.contents)
 

tests/template_tests/syntax_tests/test_for.py

@@ -87,6 +87,24 @@ class ForTagTests(SimpleTestCase):
         with self.assertRaisesMessage(TemplateSyntaxError, msg):
             self.engine.render_to_string('for-tag-unpack08', {'items': (('one', 1), ('two', 2))})
 
+    @setup({'double-quote': '{% for "k" in items %}{{ "k" }}/{% endfor %}'})
+    def test_unpack_double_quote(self):
+        msg = """'for' tag received an invalid argument: for "k" in items"""
+        with self.assertRaisesMessage(TemplateSyntaxError, msg):
+            self.engine.render_to_string('double-quote', {'items': (1, 2)})
+
+    @setup({'single-quote': "{% for 'k' in items %}{{ k }}/{% endfor %}"})
+    def test_unpack_single_quote(self):
+        msg = """'for' tag received an invalid argument: for 'k' in items"""
+        with self.assertRaisesMessage(TemplateSyntaxError, msg):
+            self.engine.render_to_string('single-quote', {'items': (1, 2)})
+
+    @setup({'vertical-bar': '{% for k|upper in items %}{{ k|upper }}/{% endfor %}'})
+    def test_unpack_vertical_bar(self):
+        msg = "'for' tag received an invalid argument: for k|upper in items"
+        with self.assertRaisesMessage(TemplateSyntaxError, msg):
+            self.engine.render_to_string('vertical-bar', {'items': (1, 2)})
+
     @setup({'for-tag-unpack09': '{% for val in items %}{{ val.0 }}:{{ val.1 }}/{% endfor %}'})
     def test_for_tag_unpack09(self):
         """