Previously, we rejected the HEAD requests that the trello integration
uses to check if the server accepts the integration.
Add decorator for returning 200 status code if request is HEAD.
Fixes: #2311.
`django.contrib.auth.get_user` function is updated in Django 1.10, due to
which everytime we update the password of the user the password hash changes.
This causes authentication failure. Previously, our code worked correctly
because we use our own session middleware and the `get_user` code had a
conditional statement which allowed our code to bypass the authentication
code.
This exists primarily in order to allow us to mock settings.DEBUG for
the purposes of rate limiting, without actually mocking
settings.DEBUG, which I suspect Django never intended one to do, and
thus caused some very strange test failures (see
https://github.com/zulip/zulip/pull/776 for details).
This makes us more consistent, since we have other wrappers
like client_patch, client_put, and client_delete.
Wrapping also will facilitate instrumentation of our posting code.
Like the recent change blocking JSON endpoints for deactivated users
and users in deactivated realms, this change is a hardening
improvement. Those users should be unable to get an active session
anyway, but if somehow one is leaked, this means they won't be able to
access any user data.