Omitting `keep_blank_values` was dropping blank query parameters.
Furthermore, converting the output of `parse_qsl` to a dictionary
was unnecessarily modifying the order of parameters since dicts
are not ordered. Fortunately `urllib.urlencode` also accepts a
sequence of two-element tuples and the order of parameters in
the encoded string will match the order of parameter tuples in the
sequence.
This adds in two redirects - `event_click` and `event_redirect` - `event_click`
to allow appending in a user ID to an event before redirect, if we require one,
and `event_redirect` to service a local evented redirect, similar to ad clicks.
`event_click` is necessary for tracking clicks from users on embeds, which are
served via redditmedia, and therefore are always anonymous. When a user clicks
through, we want to know who they were and redirect them on their way. Because
of the way we're using nginx to store events as an access log right now, this
means we'll need to use two redirects: one to append the session ID and
another to store the event with the proper session ID.
Some advertisers set their ad's url to an intermediate tracker so
they can independently track clicks. This results in a series of
redirects like this:
reddit tracker > intermediate tracker > final destination
The ad's url is communicated to the reddit tracker through a query
parameter which is urlencoded on reddit.com and then unquoted when
being handled by the reddit tracker. This unquoting causes problems
if there is an intermediate tracker with its own query string
that needs to be urlencoded. This commit adds handling for those query
strings.
Ok, now I'm getting some angst in my commit messages like my
predecessors had. I understand now. It's a terrible burden. Why must
the calendar progress? Why must numbers increment? The world is
forever turning.
The future is here.
It is 2014.
We need onload to be able to get a client-IP based
tracking validation hash, but it doesn't actually need
to do any database work to make those hashes. It also
fails a huge number of times per day. This moves the hash
calculation out to an external app with no db dependencies.
