doc/http-backend: clarify "half-auth" repo configuration

When the http-backend is set up to allow anonymous read but
authenticated write, the http-backend manual suggests
catching only the "/git-receive-pack" POST of the packfile,
not the initial "info/refs?service=git-receive-pack" GET in
which we advertise refs.

This does work and is secure, as we do not allow any write
during the info/refs request, and the information in the ref
advertisement is the same that you would get from a fetch.

However, the configuration required by the server is
slightly more complex. The default `http.receivepack`
setting is to allow pushes if the webserver tells us that
the user authenticated, and otherwise to return a 403
("Forbidden"). That works fine if authentication is turned
on completely; the initial request requires authentication,
and http-backend realizes it is OK to do a push.

But for this "half-auth" state, no authentication has
occurred during the initial ref advertisement. The
http-backend CGI therefore does not think that pushing
should be enabled, and responds with a 403. The client
cannot continue, even though the server would have allowed
it to run if it had provided credentials.

It would be much better if the server responded with a 401,
asking for credentials during the initial contact. But
git-http-backend does not know about the server's auth
configuration (so a 401 would be confusing in the case of a
true anonymous server). Unfortunately, configuring Apache to
recognize the query string and apply the auth appropriately
to receive-pack (but not upload-pack) initial requests is
non-trivial.

The site admin can work around this by just turning on
http.receivepack explicitly in its repositories. Let's
document this workaround.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
doc/http-backend: give some lighttpd config examples

The examples in the documentation are all for Apache. Let's
at least cover the basics: an anonymous server, an
authenticated server, and a "half auth" server with
anonymous read and authenticated write.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: trivial cleanups

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: add missing config variable in doc

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: properly report errors on bookmark pushes

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: fix for files with spaces

Set the maximum number of splits to make when dividing the diff stat
lines based on space characters.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: make sure fake bookmarks are updated

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: trivial test cleanups

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: redirect buggy mercurial output

Mercurial emits messages like "searching for changes", "no changes
found", etc. meant for the use of its own UI layer, which break the pipe
between transport helper and remote helper.

Since there's no way to silence Mercurial, let's redirect to standard
error.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: split bookmark handling

Will be useful for remote bookmarks.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: refactor export

No functional changes.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: update remote bookmarks

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: update tags globally

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: push to the appropriate branch

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: force remote push

Ideally we shouldn't do this, as it's not recommended in mercurial
documentation, but there's no other way to push multiple bookmarks (on
the same branch), which would be the behavior most similar to git.

At the same time, add a configuration option for the people that don't
want to risk creating new remote heads.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: show more proper errors

When cloning or pushing fails, we don't want to show a stack-trace.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: add basic author tests

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: add simple mail test

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: add 'insecure' option

If set to true acts as hg's clone/pull --insecure option.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: fix bad state issue

The problem reportedly happened after doing a push that fails, the abort
causes the state of remote-hg to go bad, this happens because
remote-hg's marks are not stored, but 'git fast-export' marks are.

Ensure that the marks are _always_ stored.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>