It's surprisingly hard to ask the sha1_file code to open a
_specific_ incarnation of a loose object. Most of the
functions take a sha1, and loop over the various object
types (packed versus loose) and locations (local versus
alternates) at a low level.

However, some tools like fsck need to look at a specific
file. This patch gives them a function they can use to open
the loose object at a given path.

The implementation unfortunately ends up repeating bits of
related functions, but there's not a good way around it
without some major refactoring of the whole sha1_file stack.
We need to mmap the specific file, then partially read the
zlib stream to know whether we're streaming or not, and then
finally either stream it or copy the data to a buffer.

We can do that by assembling some of the more arcane
internal sha1_file functions, but we end up having to
essentially reimplement unpack_sha1_file(), along with the
streaming bits of check_sha1_signature().

Still, most of the ugliness is contained in the new
function, and the interface is clean enough that it may be
reusable (though it seems unlikely anything but git-fsck
would care about opening a specific file).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The code paths in fsck for packed and loose objects are
quite different, and it is not immediately obvious that the
packed case behaves well. In particular:

  1. The fsck_loose() function always returns "0" to tell the
     iterator to keep checking more objects. Whereas
     fsck_obj_buffer() (which handles packed objects)
     returns -1. This is OK, because the callback machinery
     for verify_pack() does not stop when it sees a non-zero
     return.

  2. The fsck_loose() function sets the ERROR_OBJECT bit
     when fsck_obj() fails, whereas fsck_obj_buffer() sets it
     only when it sees a corrupt object. This turns out not
     to matter. We don't actually do anything with this bit
     except exit the program with a non-zero code, and that
     is handled already by the non-zero return from the
     function.

So there are no bugs here, but it was certainly confusing to
me. And we do not test either of the properties in t1450
(neither that a non-corruption error will caused a non-zero
exit for a packed object, nor that we keep going after
seeing the first error). Let's test both of those
conditions, so that we'll notice if any of those assumptions
becomes invalid.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When we fail to open a corrupt loose object, we report an
error and mention the filename via sha1_file_name().
However, that function will always give us a path in the
local repository, whereas the corrupt object may have come
from an alternate. The result is a very misleading error
message.

Teach the open_sha1_file() and stat_sha1_file() helpers to
pass back the path they found, so that we can report it
correctly.

Note that the pointers we return go to static storage (e.g.,
from sha1_file_name()), which is slightly dangerous.
However, these helpers are static local helpers, and the
names are used for immediately generating error messages.
The simplicity is an acceptable tradeoff for the danger.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Commit 90cf590f (fsck: optionally show more helpful info
for broken links, 2016-07-17) added a remove_loose_object()
helper, but we already had a remove_object() helper that did
the same thing. Let's combine these into one.

The implementations had a few subtle differences, so I've
tried to take the best of both:

  - the original used "sed", but the newer version avoids
    spawning an extra process

  - the original processed "$*", which was nonsense, as it
    assumed only a single sha1. Use "$1" to make that more
    clear.

  - the newer version ran an extra rev-parse, but it was not
    necessary; it's sole caller already converted the
    argument into a raw sha1

  - the original used "rm -f", whereas the new one uses
    "rm". The latter is better because it may notice a bug
    or other unexpected failure in the test. (The original
    does check that the object exists before we remove it,
    which is good, but that's a subset of the possible
    unexpected conditions).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

* maint-2.10:
  preparing for 2.10.3

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

* jk/common-main:
  common-main: stop munging argv[0] path
  git-compat-util: move content inside ifdef/endif guards

Code cleanup.

* tk/diffcore-delta-remove-unused:
  diffcore-delta: remove unused parameter to diffcore_count_changes()

Code clean-up.

* jk/create-branch-remove-unused-param:
  create_branch: drop unused "head" parameter

Typofix.

* nd/worktree-lock:
  git-worktree.txt: fix typo "to"/"two", and add comma

Doc fix.

* ps/common-info-doc:
  doc: fix location of 'info/' with $GIT_COMMON_DIR

Improve the rule to convert "unsigned char [20]" into "struct
object_id *" in contrib/coccinelle/

* rs/cocci:
  cocci: avoid self-references in object_id transformations

Update to the test framework made in 2.9 timeframe broke running
the tests under valgrind, which has been fixed.

* nd/test-helpers:
  valgrind: support test helpers

Documentation fix.

* sc/fmt-merge-msg-doc-markup-fix:
  Documentation/fmt-merge-msg: fix markup in example

Code simplification.

* rs/commit-pptr-simplify:
  commit: simplify building parents list

Documentation fix.

* jk/rebase-config-insn-fmt-docfix:
  doc: fix missing "::" in config list

A trivial clean-up to a recently graduated topic.

* ak/pre-receive-hook-template-modefix:
  pre-receive.sample: mark it executable

Portability update and workaround for builds on recent Mac OS X.

* ls/macos-update:
  travis-ci: disable GIT_TEST_HTTPD for macOS
  Makefile: set NO_OPENSSL on macOS by default

Fix for a racy false-positive test failure.

* as/merge-attr-sleep:
  t6026: clarify the point of "kill $(cat sleep.pid)"
  t6026: ensure that long-running script really is
  Revert "t6026-merge-attr: don't fail if sleep exits early"
  Revert "t6026-merge-attr: ensure that the merge driver was called"
  t6026-merge-attr: ensure that the merge driver was called
  t6026-merge-attr: don't fail if sleep exits early

Recent update to git-sh-setup (a library of shell functions that
are used by our in-tree scripted Porcelain commands) included
another shell library git-sh-i18n without specifying where it is,
relying on the $PATH.  This has been fixed to be more explicit by
prefixing $(git --exec-path) output in front.

* ak/sh-setup-dot-source-i18n-fix:
  git-sh-setup: be explicit where to dot-source git-sh-i18n from.

"git daemon" used fixed-length buffers to turn URL to the
repository the client asked for into the server side directory
path, using snprintf() to avoid overflowing these buffers, but
allowed possibly truncated paths to the directory.  This has been
tightened to reject such a request that causes overlong path to be
required to serve.

* jk/daemon-path-ok-check-truncation:
  daemon: detect and reject too-long paths

The code that we have used for the past 10+ years to cycle
4-element ring buffers turns out to be not quite portable in
theoretical world.

* rs/ring-buffer-wraparound:
  hex: make wraparound of the index into ring-buffer explicit

"git send-email" attempts to pick up valid e-mails from the
trailers, but people in real world write non-addresses there, like
"Cc: Stable <add@re.ss> # 4.8+", which broke the output depending
on the availability and vintage of Mail::Address perl module.

* mm/send-email-cc-cruft-after-address:
  Git.pm: add comment pointing to t9000
  t9000-addresses: update expected results after fix
  parse_mailboxes: accept extra text after <...> address

The command-line completion script (in contrib/) learned to
complete "git cmd ^mas<HT>" to complete the negative end of
reference to "git cmd ^master".

* cp/completion-negative-refs:
  completion: support excluding refs

Extract a small helper out of the function that reads the authors
script file "git am" internally uses.
This by itself is not useful until a second caller appears in the
future for "rebase -i" helper.

* jc/am-read-author-file:
  am: refactor read_author_script()

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

Fix for a small regression in a topic already in 'master'.

* jk/common-main:
  common-main: stop munging argv[0] path

l10n-2.11.0-rnd3.1: update ru and ca translations

* tag 'l10n-2.11.0-rnd3.1' of git://github.com/git-l10n/git-po:
  l10n: ru.po: update Russian translation
  l10n: ca.po: update translation

Since 650c4492 (common-main: call git_extract_argv0_path(),
2016-07-01), the argv[0] that is seen in cmd_main() of
individual programs is always the basename of the
executable, as common-main strips off the full path. This
can produce confusing results for git-daemon, which wants to
re-exec itself.

For instance, if the program was originally run as
"/usr/lib/git/git-daemon", it will try just re-execing
"git-daemon", which will find the first instance in $PATH.
If git's exec-path has not been prepended to $PATH, we may
find the git-daemon from a different version (or no
git-daemon at all).

Normally this isn't a problem. Git commands are run as "git
daemon", the git wrapper puts the exec-path at the front of
$PATH, and argv[0] is already "daemon" anyway. But running
git-daemon via its full exec-path, while not really a
recommended method, did work prior to 650c4492. Let's make
it work again.

The real goal of 650c4492 was not to munge argv[0], but to
reliably set the argv0_path global. The only reason it
munges at all is that one caller, the git.c wrapper,
piggy-backed on that computation to find the command
basename.  Instead, let's leave argv[0] untouched in
common-main, and have git.c do its own basename computation.

While we're at it, let's drop the return value from
git_extract_argv0_path(). It was only ever used in this one
callsite, and its dual purposes is what led to this
confusion in the first place.

Note that by changing the interface, the compiler can
confirm for us that there are no other callers storing the
return value. But the compiler can't tell us whether any of
the cmd_main() functions (besides git.c) were relying on the
basename munging. However, we can observe that prior to
650c4492, no other cmd_main() functions did that munging,
and no new cmd_main() functions have been introduced since
then. So we can't be regressing any of those cases.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

* 'russian-l10n' of https://github.com/DJm00n/git-po-ru:
  l10n: ru.po: update Russian translation

Signed-off-by: NDimitriy Ryazantcev <dimitriy.ryazantcev@gmail.com>

Signed-off-by: NAlex Henrie <alexhenrie24@gmail.com>

Signed-off-by: NMarc Branchaud <marcnarc@xiplink.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

l10n-2.11.0-rnd3

* tag 'l10n-2.11.0-rnd3' of git://github.com/git-l10n/git-po:
  l10n: de.po: translate 210 new messages
  l10n: fix unmatched single quote in error message

Translate 210 new messages came from git.pot update in fda7b092
(l10n: git.pot: v2.11.0 round 1 (209 new, 53 removed)) and c091ffbe
(l10n: git.pot: v2.11.0 round 2 (1 new, 1 removed)).
Signed-off-by: NRalf Thielow <ralf.thielow@gmail.com>

Translate one message introduced by commit:

 * 35871806 i18n: fix unmatched single quote in error message
Signed-off-by: NJiang Xin <worldhello.net@gmail.com>

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

"git archive" and "git mailinfo" stopped reading from local
configuration file with a recent update.

* jc/setup-cleanup-fix:
  archive: read local configuration
  mailinfo: read local configuration

Doc update.

* jt/trailer-with-cruft:
  doc: mention user-configured trailers

"git rebase -i" did not work well with core.commentchar
configuration variable for two reasons, both of which have been
fixed.

* js/rebase-i-commentchar-fix:
  rebase -i: handle core.commentChar=auto
  stripspace: respect repository config
  rebase -i: highlight problems with core.commentchar