You can clone with
HTTPS or Subversion.
when these settings are enabled
filter.default = full_special_chars
filter.default_flags = 0
a url like this http://mysite.com?a=value_a&b?value_b will cause an error "Disallowed Key Characters.".
the reason for this is: one of the keys in $_GET will be set to "amp;b".
this is caused by the line #205 in URI.php
$_SERVER['QUERY_STRING'] = $parts;
$_SERVER['QUERY_STRING'] = str_replace("amp;", "", $parts);
I don't think that the example URL is a valid one at all.
yes, we are using it like this, without segments.
it is a jsonp based api.
I'm not saying it's impossible to be used, it's just improper usage.