Ticket #9756: for-tag-leaves-imbalanced-context-stack.patch

django/template/defaulttags.py

@@ -128 +128 @@
             values = list(values)
         len_values = len(values)
         if len_values < 1:
+            context.pop()
             return self.nodelist_empty.render(context)
         nodelist = NodeList()
         if self.is_reversed:

tests/regressiontests/templates/tests.py

@@ -63 +63 @@
 
 class SomeOtherException(Exception):
     pass
+    
+class ContextStackException(Exception):
+    pass
 
 class SomeClass:
     def __init__(self):
@@ -203 +206 @@
                 try:
                     test_template = loader.get_template(name)
                     output = self.render(test_template, vals)
+                except ContextStackException:
+                    failures.append("Template test (TEMPLATE_STRING_IF_INVALID='%s'): %s -- FAILED. Context stack was left imbalanced" % (invalid_str, name))
+                    continue
                 except Exception, e:
                     if e.__class__ != result:
                         raise
@@ -226 +232 @@
         self.assertEqual(failures, [], '\n'.join(failures))
 
     def render(self, test_template, vals):
-        return test_template.render(template.Context(vals[1]))
+        context = template.Context(vals[1])
+        before_stack_size = len(context.dicts)
+        output = test_template.render(context)
+        if len(context.dicts) != before_stack_size:
+            raise ContextStackException
+        return output
 
     def get_template_tests(self):
         # SYNTAX --