Fixed #26830 -- Prevented the 'with' templatetag from resetting the cycle…

Fixed #26830 -- Prevented the 'with' templatetag from resetting the cycle variable to its initial state.

django/template/context.py

@@ -67,6 +67,18 @@ class BaseContext(object):
         "Set a variable in the current context"
         self.dicts[-1][key] = value
 
+    def set_upward(self, key, value):
+        """
+        Set a variable in one of the higher contexts if it exists there,
+        otherwise in the current context.
+        """
+        context = self.dicts[-1]
+        for d in reversed(self.dicts):
+            if key in d.keys():
+                context = d
+                break
+        context[key] = value
+
     def __getitem__(self, key):
         "Get a variable's value, starting at the current context and going upward"
         for d in reversed(self.dicts):

django/template/defaulttags.py

@@ -82,7 +82,7 @@ class CycleNode(Node):
         cycle_iter = context.render_context[self]
         value = next(cycle_iter).resolve(context)
         if self.variable_name:
-            context[self.variable_name] = value
+            context.set_upward(self.variable_name, value)
         if self.silent:
             return ''
         return render_value_in_context(value, context)

tests/template_tests/syntax_tests/test_cycle.py

@@ -145,3 +145,25 @@ class CycleTagTests(SimpleTestCase):
         """
         output = self.engine.render_to_string('cycle29', {'values': [1, 2, 3, 4, 5, 6, 7, 8, 8, 8, 9, 9]})
         self.assertEqual(output, 'bcabcabcccaa')
+
+    @setup({
+        'cycle30': "{% cycle 'a' 'b' 'c' as cycler silent %}"
+                   "{% for x in values %}"
+                   "{% with doesnothing=irrelevant %}"
+                   "{% ifchanged x %}"
+                   "{% cycle cycler %}{{ cycler }}"
+                   "{% else %}"
+                   "{{ cycler }}"
+                   "{% endifchanged %}"
+                   "{% endwith %}"
+                   "{% endfor %}"})
+    def test_cycle30(self):
+        """
+        A {% with %} tag shouldn't reset the {% cycle %} variable.
+        """
+        output = self.engine.render_to_string(
+            'cycle30', {
+                'irrelevant': 1,
+                'values': [1, 2, 3, 4, 5, 6, 7, 8, 8, 8, 9, 9]
+            })
+        self.assertEqual(output, 'bcabcabcccaa')

tests/template_tests/test_context.py

@@ -204,6 +204,37 @@ class ContextTests(SimpleTestCase):
         self.assertEqual(str(warns[2].message), msg2)
         self.assertEqual(str(warns[3].message), msg2)
 
+    def test_set_upward(self):
+        c = Context({'a': 1})
+        c.set_upward('a', 2)
+        self.assertEqual(c.get('a'), 2)
+
+    def test_set_upward_empty_context(self):
+        empty_context = Context()
+        empty_context.set_upward('a', 1)
+        self.assertEqual(empty_context.get('a'), 1)
+
+    def test_set_upward_with_push(self):
+        """
+        The highest context which has the given key is used.
+        """
+        c = Context({'a': 1})
+        c.push({'a': 2})
+        c.set_upward('a', 3)
+        self.assertEqual(c.get('a'), 3)
+        c.pop()
+        self.assertEqual(c.get('a'), 1)
+
+    def test_set_upward_with_push_no_match(self):
+        """
+        The highest context is used if the given key isn't found.
+        """
+        c = Context({'b': 1})
+        c.push({'b': 2})
+        c.set_upward('a', 2)
+        self.assertEqual(len(c.dicts), 3)
+        self.assertEqual(c.dicts[-1]['a'], 2)
+
 
 class RequestContextTests(SimpleTestCase):