Fixed #24877 -- Added middleware handling of response.render() errors.

tests/middleware_exceptions/middleware.py

@@ -0,0 +1,8 @@
+from __future__ import unicode_literals
+
+from django.http import HttpResponse
+
+
+class ProcessExceptionMiddleware(object):
+    def process_exception(self, request, exception):
+        return HttpResponse('Exception caught')

tests/middleware_exceptions/tests.py

@@ -486,6 +486,16 @@ class MiddlewareTests(BaseMiddlewareExceptionTest):
         # Check that the right middleware methods have been invoked
         self.assert_middleware_usage(middleware, True, True, True, True, False)
 
+    @override_settings(
+        MIDDLEWARE_CLASSES=['middleware_exceptions.middleware.ProcessExceptionMiddleware'],
+    )
+    def test_exception_in_render_passed_to_process_exception(self):
+        # Repopulate the list of middlewares since it's already been populated
+        # by setUp() before the MIDDLEWARE_CLASSES setting got overridden
+        self.client.handler.load_middleware()
+        response = self.client.get('/middleware_exceptions/exception_in_render/')
+        self.assertEqual(response.content, b'Exception caught')
+
 
 class BadMiddlewareTests(BaseMiddlewareExceptionTest):
 

tests/middleware_exceptions/urls.py

@@ -8,6 +8,7 @@ urlpatterns = [
     url(r'^middleware_exceptions/error/$', views.server_error),
     url(r'^middleware_exceptions/null_view/$', views.null_view),
     url(r'^middleware_exceptions/permission_denied/$', views.permission_denied),
+    url(r'^middleware_exceptions/exception_in_render/$', views.exception_in_render),
 
     url(r'^middleware_exceptions/template_response/$', views.template_response),
     url(r'^middleware_exceptions/template_response_error/$', views.template_response_error),

tests/middleware_exceptions/views.py

@@ -32,3 +32,11 @@ def null_view(request):
 
 def permission_denied(request):
     raise PermissionDenied()
+
+
+def exception_in_render(request):
+    class CustomHttpResponse(http.HttpResponse):
+        def render(self):
+            raise Exception('Exception in HttpResponse.render()')
+
+    return CustomHttpResponse('Error')