[1.9.x] Fixed #26306 -- Fixed memory leak in cached template loader.

Backport of ecb59cc6579402b68ddfd4499bf30edacf5963be from master

1 files changed, 39 insertions, 4 deletions

diff --git a/tests/template_tests/test_loaders.py b/tests/template_tests/test_loaders.py
index 11f20c6deb..35921e0472 100644
--- a/tests/template_tests/test_loaders.py
+++ b/tests/template_tests/test_loaders.py
@@ -49,11 +49,46 @@ class CachedLoaderTests(SimpleTestCase):
         self.assertEqual(template.origin.template_name, 'index.html')
         self.assertEqual(template.origin.loader, self.engine.template_loaders[0].loaders[0])
 
-    def test_get_template_missing(self):
+    def test_get_template_missing_debug_off(self):
+        """
+        With template debugging disabled, the raw TemplateDoesNotExist class
+        should be cached when a template is missing. See ticket #26306 and
+        docstrings in the cached loader for details.
+        """
+        self.engine.debug = False
         with self.assertRaises(TemplateDoesNotExist):
-            self.engine.get_template('doesnotexist.html')
-        e = self.engine.template_loaders[0].get_template_cache['doesnotexist.html']
-        self.assertEqual(e.args[0], 'doesnotexist.html')
+            self.engine.get_template('prod-template-missing.html')
+        e = self.engine.template_loaders[0].get_template_cache['prod-template-missing.html']
+        self.assertEqual(e, TemplateDoesNotExist)
+
+    def test_get_template_missing_debug_on(self):
+        """
+        With template debugging enabled, a TemplateDoesNotExist instance
+        should be cached when a template is missing.
+        """
+        self.engine.debug = True
+        with self.assertRaises(TemplateDoesNotExist):
+            self.engine.get_template('debug-template-missing.html')
+        e = self.engine.template_loaders[0].get_template_cache['debug-template-missing.html']
+        self.assertIsInstance(e, TemplateDoesNotExist)
+        self.assertEqual(e.args[0], 'debug-template-missing.html')
+
+    @unittest.skipIf(six.PY2, "Python 2 doesn't set extra exception attributes")
+    def test_cached_exception_no_traceback(self):
+        """
+        When a TemplateDoesNotExist instance is cached, the cached instance
+        should not contain the __traceback__, __context__, or __cause__
+        attributes that Python sets when raising exceptions.
+        """
+        self.engine.debug = True
+        with self.assertRaises(TemplateDoesNotExist):
+            self.engine.get_template('no-traceback-in-cache.html')
+        e = self.engine.template_loaders[0].get_template_cache['no-traceback-in-cache.html']
+
+        error_msg = "Cached TemplateDoesNotExist must not have been thrown."
+        self.assertIsNone(e.__traceback__, error_msg)
+        self.assertIsNone(e.__context__, error_msg)
+        self.assertIsNone(e.__cause__, error_msg)
 
     @ignore_warnings(category=RemovedInDjango20Warning)
     def test_load_template(self):