The functionality to list tree objects in the order they were seen
while traversing the commits will be used in one of the next commits,
where we teach `git describe` to describe not only commits, but blobs, too.

The change in list-objects.c is rather minimal as we'll be re-using
the infrastructure put in place of the revision walking machinery. For
example one could expect that add_pending_tree is not called, but rather
commit->tree is directly passed to the tree traversal function. This
however requires a lot more code than just emptying the queue containing
trees after each commit.
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

With traverse_trees_and_blobs factored out of the main traverse function,
the next patch can introduce an in-order revision walking with ease.

In the next patch we'll call `traverse_trees_and_blobs` from within the
loop walking the commits, such that we'll have one invocation of that
function per commit.  That is why we do not want to have memory allocations
in that function, such as we'd have if we were to use a strbuf locally.
Pass a strbuf from traverse_commit_list into the blob and tree traversing
function as a scratch pad that only needs to be allocated once.
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

l10n for Git 2.15.0 round 2 with Catalan updates

* tag 'l10n-2.15.0-rnd2.1' of git://github.com/git-l10n/git-po:
  l10n: Update Catalan translation

Signed-off-by: NJordi Mas <jmas@softcatala.org>

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

Doc flow fix.

* sg/rev-list-doc-reorder-fix:
  rev-list-options.txt: use correct directional reference

Doc markup fix.

* sb/rev-parse-show-superproject-root:
  docs: fix formatting of rev-parse's --show-superproject-working-tree

A possible oom error is now caught as a fatal error, instead of
continuing and dereferencing NULL.

* ao/path-use-xmalloc:
  path.c: use xmalloc() in add_to_trie()

Doc update.

* np/config-path-doc:
  config doc: clarify "git config --path" example

Signed-off-by: NSebastian Schuberth <sschuberth@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The descriptions of the options '--parents', '--children' and
'--graph' say "see 'History Simplification' below", although the
referred section is in fact above the description of these options.

Send readers in the right direction by saying "above" instead of
"below".
Signed-off-by: NSZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Transactions to update multiple references that involves a deletion
was quite broken in an error codepath and did not abort everything
correctly.

* mh/ref-locking-fix:
  files_transaction_prepare(): fix handling of ref lock failure
  t1404: add a bunch of tests of D/F conflicts

Add usage of xmalloc() instead of malloc() in add_to_trie() as xmalloc wraps
and checks memory allocation result.
Signed-off-by: NAndrey Okoshkin <a.okoshkin@samsung.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Since dc39e099 (files_ref_store: use a transaction to update packed
refs, 2017-09-08), failure to lock a reference has been handled
incorrectly by `files_transaction_prepare()`. If
`lock_ref_for_update()` fails in the lock-acquisition loop of that
function, it sets `ret` then breaks out of that loop. Prior to
dc39e099, that was OK, because the only thing following the loop was
the cleanup code. But dc39e099 added another blurb of code between
the loop and the cleanup. That blurb sometimes resets `ret` to zero,
making the cleanup code think that the locking was successful.

Specifically, whenever

* One or more reference deletions have been processed successfully in
  the lock-acquisition loop. (Processing the first such reference
  causes a packed-ref transaction to be initialized.)

* Then `lock_ref_for_update()` fails for a subsequent reference. Such
  a failure can happen for a number of reasons, such as the old SHA-1
  not being correct, lock contention, etc. This causes a `break` out
  of the lock-acquisition loop.

* The `packed-refs` lock is acquired successfully and
  `ref_transaction_prepare()` succeeds for the packed-ref transaction.
  This has the effect of resetting `ret` back to 0, and making the
  cleanup code think that lock acquisition was successful.

In that case, any reference updates that were processed prior to
breaking out of the loop would be carried out (loose and packed), but
the reference that couldn't be locked and any subsequent references
would silently be ignored.

This can easily cause data loss if, for example, the user was trying
to push a new name for an existing branch while deleting the old name.
After the push, the branch could be left unreachable, and could even
subsequently be garbage-collected.

This problem was noticed in the context of deleting one reference and
creating another in a single transaction, when the two references D/F
conflict with each other, like

    git update-ref --stdin <<EOF
    delete refs/foo
    create refs/foo/bar HEAD
    EOF

This triggers the above bug because the deletion is processed
successfully for `refs/foo`, then the D/F conflict causes
`lock_ref_for_update()` to fail when `refs/foo/bar` is processed. In
this case the transaction *should* fail, but instead it causes
`refs/foo` to be deleted without creating `refs/foo`. This could
easily result in data loss.

The fix is simple: instead of just breaking out of the loop, jump
directly to the cleanup code. This fixes some tests in t1404 that were
added in the previous commit.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It is currently not allowed, in a single transaction, to add one
reference and delete another reference if the two reference names D/F
conflict with each other (e.g., like `refs/foo/bar` and `refs/foo`).
The reason is that the code would need to take locks

    $GIT_DIR/refs/foo.lock
    $GIT_DIR/refs/foo/bar.lock

But the latter lock couldn't coexist with the loose reference file

    $GIT_DIR/refs/foo

, because `$GIT_DIR/refs/foo` cannot be both a directory and a file at
the same time (hence the name "D/F conflict).

Add a bunch of tests that we cleanly reject such transactions.

In fact, many of the new tests currently fail. They will be fixed in
the next commit along with an explanation.
Reported-by: NJeff King <peff@peff.net>
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

l10n for Git 2.15.0 round 2

* tag 'l10n-2.15.0-rnd2' of git://github.com/git-l10n/git-po: (22 commits)
  l10n: zh_CN: review for git v2.15.0 l10n round 2
  l10n: zh_CN: for git v2.15.0 l10n round 2
  l10n: de.po: fix typos
  l10n: de.po: translate 70 new messages
  l10n: ru.po: update Russian translation
  l10n: vi.po(3245t): Updated Vietnamese translation for v2.15.0 round 2
  l10n: sv.po: Update Swedish translation (3245t0f0u)
  l10n: fr.po: v2.15.0 round 2
  l10n: fr.po change translation of "First, rewinding"
  l10n: fr.po fix some mistakes
  l10n: Update Catalan translation
  l10n: ko.po: Update Korean translation
  l10n: es.po: v2.15.0 round 2
  l10n: git.pot: v2.15.0 round 2 (2 new, 2 removed)
  l10n: ru.po: update Russian translation
  l10n: bg.po: Updated Bulgarian translation (3245t)
  l10n: sv.po: Update Swedish translation (3245t0f0u)
  l10n: vi.po(3245t): Updated Vietnamese translation for v2.15.0
  l10n: es.po: Update translation v2.15.0 round 1
  l10n: git.pot: v2.15.0 round 1 (68 new, 36 removed)
  ...

* 'jx/zh_CN-proposed' of github.com:jiangxin/git:
  l10n: zh_CN: review for git v2.15.0 l10n round 2
  l10n: zh_CN: for git v2.15.0 l10n round 2

Signed-off-by: NRay Chen <oldsharp@gmail.com>

Translate 69 messages (3245t0f0u) for git v2.15.0-rc2.
Signed-off-by: NJiang Xin <worldhello.net@gmail.com>
Reviewed-by: N依云 <lilydjwg@gmail.com>

* 'master' of https://github.com/ralfth/git-po-de:
  l10n: de.po: fix typos
  l10n: de.po: translate 70 new messages

Signed-off-by: NAndre Hinrichs <andre.hinrichs@gmx.de>
Signed-off-by: NRalf Thielow <ralf.thielow@gmail.com>

Translate 70 new messages came from git.pot update in 25eab542
(l10n: git.pot: v2.15.0 round 1 (68 new, 36 removed)) and 9c07fab7
(l10n: git.pot: v2.15.0 round 2 (2 new, 2 removed)).
Signed-off-by: NRalf Thielow <ralf.thielow@gmail.com>

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

A regression fix for 2.11 that made the code to read the list of
alternate object stores overrun the end of the string.

* jk/info-alternates-fix:
  read_info_alternates: warn on non-trivial errors
  read_info_alternates: read contents into strbuf

"git fetch <there> <src>:<dst>" allows an object name on the <src>
side when the other side accepts such a request since Git v2.5, but
the documentation was left stale.

* jc/fetch-refspec-doc-update:
  fetch doc: src side of refspec could be full SHA-1

Many codepaths did not diagnose write failures correctly when disks
go full, due to their misuse of write_in_full() helper function,
which have been corrected.

* jk/write-in-full-fix:
  read_pack_header: handle signed/unsigned comparison in read result
  config: flip return value of store_write_*()
  notes-merge: use ssize_t for write_in_full() return value
  pkt-line: check write_in_full() errors against "< 0"
  convert less-trivial versions of "write_in_full() != len"
  avoid "write_in_full(fd, buf, len) != len" pattern
  get-tar-commit-id: check write_in_full() return against 0
  config: avoid "write_in_full(fd, buf, len) < len" pattern

Many codepaths have been updated to squelch -Wsign-compare
warnings.

* rj/no-sign-compare:
  ALLOC_GROW: avoid -Wsign-compare warnings
  cache.h: hex2chr() - avoid -Wsign-compare warnings
  commit-slab.h: avoid -Wsign-compare warnings
  git-compat-util.h: xsize_t() - avoid -Wsign-compare warnings

Assorted bugfixes and clean-ups.

* ma/ts-cleanups:
  ThreadSanitizer: add suppressions
  strbuf_setlen: don't write to strbuf_slopbuf
  pack-objects: take lock before accessing `remaining`
  convert: always initialize attr_action in convert_attrs

The scripts to drive TravisCI has been reorganized and then an
optimization to avoid spending cycles on a branch whose tip is
tagged has been implemented.

* ls/travis-scriptify:
  travis-ci: fix "skip_branch_tip_with_tag()" string comparison
  travis: dedent a few scripts that are indented overly deeply
  travis-ci: skip a branch build if equal tag is present
  travis-ci: move Travis CI code into dedicated scripts

The checkpoint command "git fast-import" did not flush updates to
refs and marks unless at least one object was created since the
last checkpoint, which has been corrected, as these things can
happen without any new object getting created.

* er/fast-import-dump-refs-on-checkpoint:
  fast-import: checkpoint: dump branches/tags/marks even if object_count==0

"git fast-export" with -M/-C option issued "copy" instruction on a
path that is simultaneously modified, which was incorrect.

* jt/fast-export-copy-modify-fix:
  fast-export: do not copy from modified file

"git branch -M a b" while on a branch that is completely unrelated
to either branch a or branch b misbehaved when multiple worktree
was in use.  This has been fixed.

* nd/worktree-kill-parse-ref:
  branch: fix branch renaming not updating HEADs correctly

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

* 'master' of https://github.com/vnwildman/git:
  l10n: vi.po(3245t): Updated Vietnamese translation for v2.15.0 round 2

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

Doc update.

* jc/branch-force-doc-readability-fix:
  branch doc: sprinkle a few commas for readability

Update the documentation for "git filter-branch" so that the filter
options are listed in the same order as they are applied, as
described in an earlier part of the doc.

* dg/filter-branch-filter-order-doc:
  doc: list filter-branch subdirectory-filter first