t6300: test sort with multiple keys

Documentation of git-for-each-ref says that --sort=<key> option can be
used multiple times, in which case the last key becomes the primary key.
However this functionality was never checked in test suite and is
currently broken. This commit adds appropriate test in preparation for fix.

Signed-off-by: Kacper Kornet <draenog@pld-linux.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
for-each-ref: Fix sort with multiple keys

The linked list describing sort options was not correctly set up in
opt_parse_sort. In the result, contrary to the documentation, only the
last of multiple --sort options to git-for-each-ref was taken into
account. This commit fixes it.

Signed-off-by: Kacper Kornet <draenog@pld-linux.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
specifying ranges: we did not mean to make ".." an empty set

Either end of revision range operator can be omitted to default to HEAD,
as in "origin.." (what did I do since I forked) or "..origin" (what did
they do since I forked).  But the current parser interprets ".."  as an
empty range "HEAD..HEAD", and worse yet, because ".." does exist on the
filesystem, we get this annoying output:

  $ cd Documentation/howto
  $ git log .. ;# give me recent commits that touch Documentation/ area.
  fatal: ambiguous argument '..': both revision and filename
  Use '--' to separate filenames from revisions

Surely we could say "git log ../" or even "git log -- .." to disambiguate,
but we shouldn't have to.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
apply: compute patch->def_name correctly under -p0

Back when "git apply" was written, we made sure that the user can
skip more than the default number of path components (i.e. 1) by
giving "-p<n>", but the logic for doing so was built around the
notion of "we skip N slashes and stop".  This obviously does not
work well when running under -p0 where we do not want to skip any,
but still want to skip SP/HT that separates the pathnames of
preimage and postimage and want to reject absolute pathnames.

Stop using "stop_at_slash()", and instead introduce a new helper
"skip_tree_prefix()" with similar logic but works correctly even for
the -p0 case.

This is an ancient bug, but has been masked for a long time because
most of the patches are text and have other clues to tell us the
name of the preimage and the postimage.

Noticed by Colin McCabe.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
doc: "git checkout -b/-B/--orphan" always takes a branch name

While the synopsis section makes it clear that the new branch name
is the parameter to these flags, the option description did not.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
t5550: put auth-required repo in auth/dumb

In most of our tests, we put repos to be accessed by dumb
protocols in /dumb, and repos to be accessed by smart
protocols in /smart.  In our test apache setup, the whole
/auth hierarchy requires authentication. However, we don't
bother to split it by smart and dumb here because we are not
currently testing smart-http authentication at all.

That will change in future patches, so let's be explicit
that we are interested in testing dumb access here. This
also happens to match what t5540 does for the push tests.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t5550: factor out http auth setup

The t5550 script sets up a nice askpass helper for
simulating user input and checking what git prompted for.
Let's make it available to other http scripts by migrating
it to lib-httpd.

We can use this immediately in t5540 to make our tests more
robust (previously, we did not check at all that hitting the
password-protected repo actually involved a password).
Unfortunately, we end up failing the test because the
current code erroneously prompts twice (once for
git-remote-http, and then again when the former spawns
git-http-push).

More importantly, though, it will let us easily add
smart-http authentication tests in t5541 and t5551; we
currently do not test smart-http authentication at all.

As part of making it generic, let's always look for and
store auxiliary askpass files at the top-level trash
directory; this makes it compatible with t5540, which runs
some tests from sub-repositories. We can abstract away the
ugliness with a short helper function.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t/lib-httpd: only route auth/dumb to dumb repos

Our test apache config points all of auth/ directly to the
on-disk repositories via an Alias directive. This works fine
because everything authenticated is currently in auth/dumb,
which is a subset.  However, this would conflict with a
ScriptAlias for auth/smart (which will come in future
patches), so let's narrow the Alias.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t/lib-httpd: recognize */smart/* repos as smart-http

We do not currently test authentication for smart-http repos
at all. Part of the infrastructure to do this is recognizing
that auth/smart is indeed a smart-http repo.

The current apache config recognizes only "^/smart/*" as
smart-http. Let's instead treat anything with /smart/ in the
URL as smart-http. This is obviously a stupid thing to do
for a real production site, but for our test suite we know
that our repositories will not have this magic string in the
name.

Note that we will route /foo/smart/bar.git directly to
git-http-backend/bar.git; in other words, everything before
the "/smart/" is irrelevant to finding the repo on disk (but
may impact apache config, for example by triggering auth
checks).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t: test basic smart-http authentication

We do not currently test authentication over smart-http at
all. In theory, it should work exactly as it does for dumb
http (which we do test). It does indeed work for these
simple tests, but this patch lays the groundwork for more
complex tests in future patches.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t: test http access to "half-auth" repositories

Some sites set up http access to repositories such that
fetching is anonymous and unauthenticated, but pushing is
authenticated. While there are multiple ways to do this, the
technique advertised in the git-http-backend manpage is to
block access to locations matching "/git-receive-pack$".

Let's emulate that advice in our test setup, which makes it
clear that this advice does not actually work.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
http: factor out http error code handling

Most of our http requests go through the http_request()
interface, which does some nice post-processing on the
results. In particular, it handles prompting for missing
credentials as well as approving and rejecting valid or
invalid credentials. Unfortunately, it only handles GET
requests. Making it handle POSTs would be quite complex, so
let's pull result handling code into its own function so
that it can be reused from the POST code paths.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
http: prompt for credentials on failed POST

All of the smart-http GET requests go through the http_get_*
functions, which will prompt for credentials and retry if we
see an HTTP 401.

POST requests, however, do not go through any central point.
Moreover, it is difficult to retry in the general case; we
cannot assume the request body fits in memory or is even
seekable, and we don't know how much of it was consumed
during the attempt.

Most of the time, this is not a big deal; for both fetching
and pushing, we make a GET request before doing any POSTs,
so typically we figure out the credentials during the first
request, then reuse them during the POST. However, some
servers may allow a client to get the list of refs from
receive-pack without authentication, and then require
authentication when the client actually tries to POST the
pack.

This is not ideal, as the client may do a non-trivial amount
of work to generate the pack (e.g., delta-compressing
objects). However, for a long time it has been the
recommended example configuration in git-http-backend(1) for
setting up a repository with anonymous fetch and
authenticated push. This setup has always been broken
without putting a username into the URL. Prior to commit
986bbc0, it did work with a username in the URL, because git
would prompt for credentials before making any requests at
all. However, post-986bbc0, it is totally broken. Since it
has been advertised in the manpage for some time, we should
make sure it works.

Unfortunately, it is not as easy as simply calling post_rpc
again when it fails, due to the input issue mentioned above.
However, we can still make this specific case work by
retrying in two specific instances:

  1. If the request is large (bigger than LARGE_PACKET_MAX),
     we will first send a probe request with a single flush
     packet. Since this request is static, we can freely
     retry it.

  2. If the request is small and we are not using gzip, then
     we have the whole thing in-core, and we can freely
     retry.

That means we will not retry in some instances, including:

  1. If we are using gzip. However, we only do so when
     calling git-upload-pack, so it does not apply to
     pushes.

  2. If we have a large request, the probe succeeds, but
     then the real POST wants authentication. This is an
     extremely unlikely configuration and not worth worrying
     about.

While it might be nice to cover those instances, doing so
would be significantly more complex for very little
real-world gain. In the long run, we will be much better off
when curl learns to internally handle authentication as a
callback, and we can cleanly handle all cases that way.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'kk/maint-for-each-ref-multi-sort' into maint-1.7.11

"git for-each-ref" did not honor multiple "--sort=<key>" arguments
correctly.

* kk/maint-for-each-ref-multi-sort:
  for-each-ref: Fix sort with multiple keys
  t6300: test sort with multiple keys
Merge branch 'jk/maint-http-half-auth-push' into maint-1.7.11

Pushing to smart HTTP server with recent Git fails without having
the username in the URL to force authentication, if the server is
configured to allow GET anonymously, while requiring authentication
for POST.

* jk/maint-http-half-auth-push:
  http: prompt for credentials on failed POST
  http: factor out http error code handling
  t: test http access to "half-auth" repositories
  t: test basic smart-http authentication
  t/lib-httpd: recognize */smart/* repos as smart-http
  t/lib-httpd: only route auth/dumb to dumb repos
  t5550: factor out http auth setup
  t5550: put auth-required repo in auth/dumb
Merge branch 'jc/maint-doc-checkout-b-always-takes-branch-name' into maint-1.7.11

The synopsis said "checkout [-B branch]" to make it clear the
branch name is a parameter to the option, but the heading for the
option description was "-B::", not "-B branch::", making the
documentation misleading.

* jc/maint-doc-checkout-b-always-takes-branch-name:
  doc: "git checkout -b/-B/--orphan" always takes a branch name
Merge branch 'jc/dotdot-is-parent-directory' into maint-1.7.11

"git log .." errored out saying it is both rev range and a path when
there is no disambiguating "--" is on the command line.  Update the
command line parser to interpret ".." as a path in such a case.

* jc/dotdot-is-parent-directory:
  specifying ranges: we did not mean to make ".." an empty set
Merge branch 'jc/apply-binary-p0' into maint-1.7.11

"git apply -p0" did not parse pathnames on "diff --git" line
correctly.  This caused patches that had pathnames in no other
places to be mistakenly rejected (most notably, binary patch that
does not rename nor change mode).  Textual patches, renames or mode
changes have preimage and postimage pathnames in different places in
a form that can be parsed unambiguously and did not suffer from this
problem.

* jc/apply-binary-p0:
  apply: compute patch->def_name correctly under -p0
Merge branch 'maint-1.7.11' into maint
Further merging in preparation for 1.7.12.1

Describe the following in the draft release notes:

 . jc/apply-binary-p0
 . jc/dotdot-is-parent-directory
 . jc/maint-doc-checkout-b-always-takes-branch-name
 . jk/maint-http-half-auth-push
 . kk/maint-for-each-ref-multi-sort

Yet to be merged before 1.7.12.1 are:

 . jk/config-warn-on-inaccessible-paths
 . jk/maint-quiet-is-synonym-to-s-in-log
 . mz/cherry-pick-cmdline-order

Signed-off-by: Junio C Hamano <gitster@pobox.com>