Form data exposed by hgweb is post-processed to expand certain
shortcuts. For example, URLs with "?cs=@" is essentially expanded to
"?cmd=changeset&node=@". And the URL router treats this the same
as "/changeset/@".
These shortcuts were initially added in 2005 in 34cb3957d875 and
964baa35faf8. They have rarely been touched in the last decade (just
moving code around a bit).
We have almost no test coverage of this feature. AFAICT no templates
reference URLs of this form. I even looked at the initial version
of paper and coal from ~2008 and they use the "/command/params" URL
form and not these shortcuts.
Furthermore, I couldn't even get some shortcuts to work! For example,
"?sl=@" attempts to do a revision search instead of showing shortlog
starting at revision @. Maybe I'm just doing it wrong?
Because this is ancient, mostly untested code, there is a migration
path to something better, and because anyone passionate enough to
preserve URLs can install URL redirects, let's nuke the feature.
.. bc::
Query string shorts in hgweb like ``?cs=@`` have been removed. Use URLs of the form ``/:cmd`` instead.