The actual function was overcomplicated and was designed to check
whether a stream existed by name, not by ID, so there was no value in
having it be used for checking if a stream existed by ID.
The goal of this library is to make it a lot easier to prevent bugs
like CVE-2017-0881 by having all of our views logic for fetching a
stream go through a couple carefully tested code paths.
A bug in Zulip's implementation of the "stream exists" endpoint meant
that any user of a Zulip server could subscribe to an invite-only
stream without needing to be invited by using the "autosubscribe"
argument.
Thanks to Rafid Aslam for discovering this issue.
Apparently, we weren't returning the `json_error`, resulting in users
encountering this condition receiving a 500, rather than the proper
40x error.
This fixes a regresion introduced in 9ae68ade8b.
Previously, if you searched for ':offi..' you would see both 🏢 and
:office_building: as possible completions, both of which are shortcodes for
the same unicode codepoint (and hence which have the same image). Also, we
sort the emoji in our emoji pickers alphabetically by shortcode, and so the
images for 🏢 and :office_building: show up next to each other, which
looks like a bug. This removes :office_building: as a shortcode, along with
several hundred other duplicates. It leaves some duplicates in that won't
give autocomplete or alphabetical ordering a problem, like (🚗,
:automobile:).
This results in a brief service interruption (not a graceful restart),
but fixes a bug where on a `supervisorctl restart zulip-django`, we'd
end up leaking a bunch of uwsgi processes.
The mechanism was that sending SIGHUP to uwsgi was a command for it to
gracefully restart, so it'd start doing that (whereas supervisor
expected it to be dying)... and then supervisor would start up the new
uwsgi process group, resulting in 2 uwsgi process groups running.
This, in turn, led to a memory leak that could eventually result in
OOM kills.