Inconsistency in the default views

[Aymeric Augustin]

django.views.defaults.permission_denied will respond <h1>403 Forbidden</h1> if no 403.html template is found. This behavior was introduced to provide backwards compatibility. Generally speaking, it is a reasonable fallback.

I believe that page_not_found and server_error could benefit from a similar fallback.

That would prevent 404s from turning into 500s when there's no 404.html template. I know we want to encourage custom error pages, but in case a developer skips them, a bare <h1>404 Not Found</h1> is less damaging than a 500 with a backtrace or no content at all.

[Claude Paroz]

#18948 demonstrates a bad side-effect of the current situation.

[Claude Paroz]

Removed 404.html and 500.html requirements

[Jannis Leidel]

+1

[Claude Paroz <claude@…>]

In 8bd7b598b6de1be1e3f72f3a1ee62803b1c02010:

Fixed #18807 -- Made 404.html and 500.html optional

Thanks Aymeric Augustin for the report and Jannis Leidel for the
review.

[Jon Dufresne <jon.dufresne@…>]

In ff09add2:

Refs #18807 -- Removed unused exception handler from Client.request().

Unused since 8bd7b598b6de1be1e3f72f3a1ee62803b1c02010.