Commit Graph

65195 Commits

Author SHA1 Message Date
Derrick Stolee
a3eca58445 sparse-checkout: refuse to add to bad patterns
When in cone mode sparse-checkout, it is unclear how 'git
sparse-checkout add <dir1> ...' should behave if the existing
sparse-checkout file does not match the cone mode patterns. Change the
behavior to fail with an error message about the existing patterns.

Also, all cone mode patterns start with a '/' character, so add that
restriction. This is necessary for our example test 'cone mode: warn on
bad pattern', but also requires modifying the example sparse-checkout
file we use to test the warnings related to recognizing cone mode
patterns.

This error checking would cause a failure further down the test script
because of a test that adds non-cone mode patterns without cleaning them
up. Perform that cleanup as part of the test now.

Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-30 14:39:57 -08:00
Derrick Stolee
391c3a1020 sparse-checkout: fix OOM error with mixed patterns
Add a test to t1091-sparse-checkout-builtin.sh that would result in an
infinite loop and out-of-memory error before this change. The issue
relies on having non-cone-mode patterns while trying to modify the
patterns in cone-mode.

The fix is simple, allowing us to break from the loop when the input
path does not contain a slash, as the "dir" pattern we added does not.

This is only a fix to the critical out-of-memory error. A better
response to such a strange state will follow in a later change.

Reported-by: Calbabreaker <calbabreaker@gmail.com>
Helped-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-30 14:39:57 -08:00
Derrick Stolee
a481d4378c sparse-checkout: fix segfault on malformed patterns
Then core.sparseCheckoutCone is enabled, the sparse-checkout patterns are
used to populate two hashsets that accelerate pattern matching. If the user
modifies the sparse-checkout file outside of the 'sparse-checkout' builtin,
then strange patterns can happen, triggering some error checks.

One of these error checks is possible to hit when some special characters
exist in a line. A warning message is correctly written to stderr, but then
there is additional logic that attempts to remove the line from the hashset
and free the data. This leads to a segfault in the 'git sparse-checkout
list' command because it iterates over the contents of the hashset, which is
now invalid.

The fix here is to stop trying to remove from the hashset. In addition,
we disable cone mode sparse-checkout because of the malformed data. This
results in the pattern-matching working with a possibly-slower
algorithm, but using the patterns as they are in the sparse-checkout
file.

This also changes the behavior of commands such as 'git sparse-checkout
list' because the output patterns will be the contents of the
sparse-checkout file instead of the list of directories. This is an
existing behavior for other types of bad patterns.

Add a test that triggers the segfault without the code change.

Reported-by: John Burnett <johnburnett@johnburnett.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-30 14:39:57 -08:00
Junio C Hamano
e773545c7f The second batch 2021-12-10 14:35:16 -08:00
Junio C Hamano
3e1dbfa135 Merge branch 'en/rebase-x-fix'
"git rebase -x" added an unnecessary 'exec' instructions before
'noop', which has been corrected.

* en/rebase-x-fix:
  sequencer: avoid adding exec commands for non-commit creating commands
2021-12-10 14:35:16 -08:00
Junio C Hamano
7d53ff402a Merge branch 'cb/add-p-single-key-fix'
The single-key-input mode in "git add -p" had some code to handle
keys that generate a sequence of input via ReadKey(), which did not
handle end-of-file correctly, which has been fixed.

* cb/add-p-single-key-fix:
  add -p: avoid use of undefined $key when ReadKey -> EOF
2021-12-10 14:35:16 -08:00
Junio C Hamano
25be7ec4bf Merge branch 'cb/mingw-gmtime-r'
Build fix on Windows.

* cb/mingw-gmtime-r:
  mingw: avoid fallback for {local,gm}time_r()
2021-12-10 14:35:15 -08:00
Junio C Hamano
4b1197ab5a Merge branch 'yn/complete-date-format-options'
The completion script (in contrib/) learns that the "--date"
option of commands from the "git log" family takes "human" and
"auto" as valid values.

* yn/complete-date-format-options:
  completion: add human and auto: date format
2021-12-10 14:35:15 -08:00
Junio C Hamano
bb47eee9df Merge branch 'em/missing-pager'
When a non-existent program is given as the pager, we tried to
reuse an uninitialized child_process structure and crashed, which
has been fixed.

* em/missing-pager:
  pager: fix crash when pager program doesn't exist
2021-12-10 14:35:15 -08:00
Junio C Hamano
670703e9d6 Merge branch 'mp/absorb-submodule-git-dir-upon-deinit'
"git submodule deinit" for a submodule whose .git metadata
directory is embedded in its working tree refused to work, until
the submodule gets converted to use the "absorbed" form where the
metadata directory is stored in superproject, and a gitfile at the
top-level of the working tree of the submodule points at it.  The
command is taught to convert such submodules to the absorbed form
as needed.

* mp/absorb-submodule-git-dir-upon-deinit:
  submodule: absorb git dir instead of dying on deinit
2021-12-10 14:35:15 -08:00
Junio C Hamano
d67fc4bf0b Merge branch 'bc/require-c99'
Weather balloon to break people with compilers that do not support
C99.

* bc/require-c99:
  git-compat-util: add a test balloon for C99 support
2021-12-10 14:35:14 -08:00
Junio C Hamano
b8148376a2 Merge branch 'hn/create-reflog-simplify'
A small simplification of API.

* hn/create-reflog-simplify:
  refs: drop force_create argument of create_reflog API
2021-12-10 14:35:13 -08:00
Junio C Hamano
cdac0caddd Merge branch 'jt/midx-doc-fix'
Docfix.

* jt/midx-doc-fix:
  Doc: no midx and partial clone relation
2021-12-10 14:35:13 -08:00
Junio C Hamano
97991dfab7 Merge branch 'jk/t7006-sigpipe-tests-fix'
The function to cull a child process and determine the exit status
had two separate code paths for normal callers and callers in a
signal handler, and the latter did not yield correct value when the
child has caught a signal.  The handling of the exit status has
been unified for these two code paths.  An existing test with
flakiness has also been corrected.

* jk/t7006-sigpipe-tests-fix:
  t7006: simplify exit-code checks for sigpipe tests
  t7006: clean up SIGPIPE handling in trace2 tests
  run-command: unify signal and regular logic for wait_or_whine()
2021-12-10 14:35:13 -08:00
Junio C Hamano
8bb6fe853f Merge branch 'jk/refs-g11-workaround'
Workaround for a false-alarm by gcc-11

* jk/refs-g11-workaround:
  refs: work around gcc-11 warning with REF_HAVE_NEW
2021-12-10 14:35:12 -08:00
Junio C Hamano
353a27ad95 Merge branch 'jk/fetch-pack-avoid-sigpipe-to-index-pack'
"git fetch", when received a bad packfile, can fail with SIGPIPE.
This wasn't wrong per-se, but we now detect the situation and fail
in a more predictable way.

* jk/fetch-pack-avoid-sigpipe-to-index-pack:
  fetch-pack: ignore SIGPIPE when writing to index-pack
2021-12-10 14:35:12 -08:00
Junio C Hamano
85ac30ff5c Merge branch 'hk/ci-checkwhitespace-commentfix'
Comment fix.

* hk/ci-checkwhitespace-commentfix:
  ci(check-whitespace): update stale file top comments
2021-12-10 14:35:12 -08:00
Junio C Hamano
f0850875fd Merge branch 'vd/sparse-reset'
Various operating modes of "git reset" have been made to work
better with the sparse index.

* vd/sparse-reset:
  unpack-trees: improve performance of next_cache_entry
  reset: make --mixed sparse-aware
  reset: make sparse-aware (except --mixed)
  reset: integrate with sparse index
  reset: expand test coverage for sparse checkouts
  sparse-index: update command for expand/collapse test
  reset: preserve skip-worktree bit in mixed reset
  reset: rename is_missing to !is_in_reset_tree
2021-12-10 14:35:12 -08:00
Junio C Hamano
4ee5cacc16 Merge branch 'tl/midx-docfix'
Doc mark-up fix.

* tl/midx-docfix:
  midx: fix a formatting issue in "multi-pack-index.txt"
2021-12-10 14:35:11 -08:00
Junio C Hamano
cb136bd852 Merge branch 'po/size-t-for-vs'
On platforms where ulong is shorter than size_t, code paths that
shifted 1 or 1U to the left lacked the necessary cast to size_t,
which have been corrected.

* po/size-t-for-vs:
  object-file.c: LLP64 compatibility, upcast unity for left shift
  diffcore-delta.c: LLP64 compatibility, upcast unity for left shift
  repack.c: LLP64 compatibility, upcast unity for left shift
2021-12-10 14:35:10 -08:00
Junio C Hamano
fc0e3e02c9 Merge branch 'rs/mergesort'
Bitop fix for platforms whose "long" is 32-bit.

* rs/mergesort:
  mergesort: avoid left shift overflow
2021-12-10 14:35:10 -08:00
Junio C Hamano
8e715503f1 Merge branch 'ah/advice-pull-has-no-preference-between-rebase-and-merge'
The advice message given by "git pull" when the user hasn't made a
choice between merge and rebase still said that the merge is the
default, which no longer is the case.  This has been corrected.

* ah/advice-pull-has-no-preference-between-rebase-and-merge:
  pull: don't say that merge is "the default strategy"
2021-12-10 14:35:09 -08:00
Junio C Hamano
7b11728a7b Merge branch 'ab/checkout-branch-info-leakfix'
Leakfix.

* ab/checkout-branch-info-leakfix:
  checkout: fix "branch info" memory leaks
2021-12-10 14:35:09 -08:00
Junio C Hamano
b0b5337876 Merge branch 'jk/t5319-midx-corruption-test-deflake'
Test fix.

* jk/t5319-midx-corruption-test-deflake:
  t5319: corrupt more bytes of the midx checksum
2021-12-10 14:35:08 -08:00
Junio C Hamano
9b0a970ace Merge branch 'js/trace2-avoid-recursive-errors'
trace2 error code path fix.

* js/trace2-avoid-recursive-errors:
  trace2: disable tr2_dst before warning on write errors
2021-12-10 14:35:08 -08:00
Junio C Hamano
2d5b70de2d Merge branch 'jt/pack-header-lshift-overflow'
The code to decode the length of packed object size has been
corrected.

* jt/pack-header-lshift-overflow:
  packfile: avoid overflowing shift during decode
2021-12-10 14:35:08 -08:00
Junio C Hamano
a0f3df5d64 Merge branch 'jk/jump-merge-with-pathspec'
The "merge" subcommand of "git jump" (in contrib/) silently ignored
pathspec and other parameters.

* jk/jump-merge-with-pathspec:
  git-jump: pass "merge" arguments to ls-files
2021-12-10 14:35:08 -08:00
Junio C Hamano
a9c84980d0 Merge branch 'jk/test-bitmap-fix'
Tighten code for testing pack-bitmap.

* jk/test-bitmap-fix:
  test_bitmap_hashes(): handle repository without bitmaps
2021-12-10 14:35:08 -08:00
Junio C Hamano
d1305bd3cf Merge branch 'ab/generate-command-list'
Build optimization.

* ab/generate-command-list:
  generate-cmdlist.sh: don't parse command-list.txt thrice
  generate-cmdlist.sh: replace "grep' invocation with a shell version
  generate-cmdlist.sh: do not shell out to "sed"
  generate-cmdlist.sh: stop sorting category lines
  generate-cmdlist.sh: replace for loop by printf's auto-repeat feature
  generate-cmdlist.sh: run "grep | sort", not "sort | grep"
  generate-cmdlist.sh: don't call get_categories() from category_list()
  generate-cmdlist.sh: spawn fewer processes
  generate-cmdlist.sh: trivial whitespace change
  command-list.txt: sort with "LC_ALL=C sort"
2021-12-10 14:35:08 -08:00
Junio C Hamano
03194a1afa Merge branch 'tw/var-default-branch'
"git var GIT_DEFAULT_BRANCH" is a way to see what name is used for
the newly created branch if "git init" is run.

* tw/var-default-branch:
  var: add GIT_DEFAULT_BRANCH variable
2021-12-10 14:35:07 -08:00
Junio C Hamano
1c39c822a9 Merge branch 'jk/strbuf-addftime-seconds-since-epoch'
The "--date=format:<strftime>" gained a workaround for the lack of
system support for a non-local timezone to handle "%s" placeholder.

* jk/strbuf-addftime-seconds-since-epoch:
  strbuf_addftime(): handle "%s" manually
2021-12-10 14:35:07 -08:00
Junio C Hamano
bd16b3c39f Merge branch 'js/ci-no-directional-formatting'
CI has been taught to catch some Unicode directional formatting
sequence that can be used in certain mischief.

* js/ci-no-directional-formatting:
  ci: disallow directional formatting
2021-12-10 14:35:06 -08:00
Junio C Hamano
3d2dce168f Merge branch 'jc/fix-first-object-walk'
Doc update.

* jc/fix-first-object-walk:
  docs: add headers in MyFirstObjectWalk
  docs: fix places that break compilation in MyFirstObjectWalk
2021-12-10 14:35:05 -08:00
Junio C Hamano
b5e7f5e5b1 Merge branch 'if/redact-packfile-uri'
Redact the path part of packfile URI that appears in the trace output.

* if/redact-packfile-uri:
  http-fetch: redact url on die() message
  fetch-pack: redact packfile urls in traces
2021-12-10 14:35:04 -08:00
Junio C Hamano
23c83fc473 Merge branch 'ja/doc-cleanup'
Doc update.

* ja/doc-cleanup:
  init doc: --shared=0xxx does not give umask but perm bits
  doc: git-init: clarify file modes in octal.
  doc: git-http-push: describe the refs as pattern pairs
  doc: uniformize <URL> placeholders' case
  doc: use three dots for indicating repetition instead of star
  doc: git-ls-files: express options as optional alternatives
  doc: use only hyphens as word separators in placeholders
  doc: express grammar placeholders between angle brackets
  doc: split placeholders as individual tokens
  doc: fix git credential synopsis
2021-12-10 14:35:03 -08:00
Junio C Hamano
6d1e149ac0 Merge branch 'gc/remote-with-fewer-static-global-variables'
Code clean-up to eventually allow information on remotes defined
for an arbitrary repository to be read.

* gc/remote-with-fewer-static-global-variables:
  remote: die if branch is not found in repository
  remote: remove the_repository->remote_state from static methods
  remote: use remote_state parameter internally
  remote: move static variables into per-repository struct
  t5516: add test case for pushing remote refspecs
2021-12-10 14:35:02 -08:00
Junio C Hamano
5396d7b298 Merge branch 'vd/sparse-sparsity-fix-on-read'
Ensure that the sparseness of the in-core index matches the
index.sparse configuration specified by the repository immediately
after the on-disk index file is read.

* vd/sparse-sparsity-fix-on-read:
  sparse-index: update do_read_index to ensure correct sparsity
  sparse-index: add ensure_correct_sparsity function
  sparse-index: avoid unnecessary cache tree clearing
  test-read-cache.c: prepare_repo_settings after config init
2021-12-10 14:35:01 -08:00
Junio C Hamano
83113c4268 Merge branch 'cw/protocol-v2-doc-fix'
Doc update.

* cw/protocol-v2-doc-fix:
  protocol-v2.txt: align delim-pkt spec with usage
2021-12-10 14:35:00 -08:00
brian m. carlson
7bc341e21b git-compat-util: add a test balloon for C99 support
The C99 standard was released in January 1999, now 22 years ago.  It
provides a variety of useful features, including variadic arguments for
macros, declarations after statements, designated initializers, and a
wide variety of other useful features, many of which we already use.

We'd like to take advantage of these features, but we want to be
cautious.  As far as we know, all major compilers now support C99 or a
later C standard, such as C11 or C17.  POSIX has required C99 support as
a requirement for the 2001 revision, so we can safely assume any POSIX
system which we are interested in supporting has C99.

Even MSVC, long a holdout against modern C, now supports both C11 and
C17 with an appropriate update.  Moreover, even if people are using an
older version of MSVC on these systems, they will generally need some
implementation of the standard Unix utilities for the testsuite, and GNU
coreutils, the most common option, has required C99 since 2009.
Therefore, we can safely assume that a suitable version of GCC or clang
is available to users even if their version of MSVC is not sufficiently
capable.

Let's add a test balloon to git-compat-util.h to see if anyone is using
an older compiler.  We'll add a comment telling people how to enable
this functionality on GCC and Clang, even though modern versions of both
will automatically do the right thing, and ask people still experiencing
a problem to report that to us on the list.

Note that C89 compilers don't provide the __STDC_VERSION__ macro, so we
use a well-known hack of using "- 0".  On compilers with this macro, it
doesn't change the value, and on C89 compilers, the macro will be
replaced with nothing, and our value will be 0.

For sparse, we explicitly request the gnu99 style because we've
traditionally taken advantage of some GCC- and clang-specific extensions
when available and we'd like to retain the ability to do that.  sparse
also defaults to C89 without it, so things will fail for us if we don't.

Update the cmake configuration to require C11 for MSVC.  We do this
because this will make MSVC to use C11, since it does not explicitly
support C99.  We do this with a compiler options because setting the
C_STANDARD option does not work in our CI on MSVC and at the moment, we
don't want to require C11 for Unix compilers.

In the Makefile, don't set any compiler flags for the compiler itself,
since on some systems, such as FreeBSD, we actually need C11, and asking
for C99 causes things to fail to compile.  The error message should make
it obvious what's going wrong and allow a user to set the appropriate
option when building in the event they're using a Unix compiler that
doesn't support it by default.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-01 14:50:01 -08:00
Philip Oakley
26de1fc0c9 object-file.c: LLP64 compatibility, upcast unity for left shift
Visual Studio reports C4334 "was 64-bit shift intended" warning because
of size miss-match.

Promote unity to the matching type to fit with the assignment.

Signed-off-by: Philip Oakley <philipoakley@iee.email>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-01 14:48:10 -08:00
Philip Oakley
62e8452c8c diffcore-delta.c: LLP64 compatibility, upcast unity for left shift
Visual Studio reports C4334 "was 64-bit shift intended" warning
because of size miss-match.

Promote unity to the matching type to fit with its subsequent operation.

Signed-off-by: Philip Oakley <philipoakley@iee.email>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-01 14:48:10 -08:00
Philip Oakley
a43abad1e3 repack.c: LLP64 compatibility, upcast unity for left shift
Visual Studio reports C4334 "was 64-bit shift intended" warning
because of size mismatch.

Promote unity to the matching type to fit with the `&` operator.

Signed-off-by: Philip Oakley <philipoakley@iee.email>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-01 14:48:09 -08:00
Elijah Newren
cc9dcdee61 sequencer: avoid adding exec commands for non-commit creating commands
The `--exec <cmd>` is documented as

    Append "exec <cmd>" after each line creating a commit in the final
    history.
    ...
    If --autosquash is used, "exec" lines will not be appended for the
    intermediate commits, and will only appear at the end of each
    squash/fixup series.

Unfortunately, it would also add exec commands after non-pick
operations, such as 'no-op', which could be seen for example with
    git rebase -i --exec true HEAD

todo_list_add_exec_commands() intent was to insert exec commands after
each logical pick, while trying to consider a chains of fixup and squash
commits to be part of the pick before it.  So it would keep an 'insert'
boolean tracking if it had seen a pick or merge, but not write the exec
command until it saw the next non-fixup/squash command.  Since that
would make it miss the final exec command, it had some code that would
check whether it still needed to insert one at the end, but instead of a
simple

    if (insert)

it had a

    if (insert || <condition that is always true>)

That's buggy; as per the docs, we should only add exec commands for
lines that create commits, i.e. only if insert is true.  Fix the
conditional.

There was one testcase in the testsuite that we tweak for this change;
it was introduced in 54fd3243da ("rebase -i: reread the todo list if
`exec` touched it", 2017-04-26), and was merely testing that after an
exec had fired that the todo list would be re-read.  The test at the
time would have worked given any revision at all, though it would only
work with 'HEAD' as a side-effect of this bug.  Since we're fixing this
bug, choose something other than 'HEAD' for that test.

Finally, add a testcase that verifies when we have no commits to pick,
that we get no exec lines in the generated todo list.

Reported-by: Nikita Bobko <nikitabobko@gmail.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-29 22:53:26 -08:00
Junio C Hamano
abe6bb3905 The first batch to start the current cycle
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-29 15:41:51 -08:00
Junio C Hamano
f9ba6acaa9 Merge branch 'mc/clean-smudge-with-llp64'
The clean/smudge conversion code path has been prepared to better
work on platforms where ulong is narrower than size_t.

* mc/clean-smudge-with-llp64:
  clean/smudge: allow clean filters to process extremely large files
  odb: guard against data loss checking out a huge file
  git-compat-util: introduce more size_t helpers
  odb: teach read_blob_entry to use size_t
  t1051: introduce a smudge filter test for extremely large files
  test-lib: add prerequisite for 64-bit platforms
  test-tool genzeros: generate large amounts of data more efficiently
  test-genzeros: allow more than 2G zeros in Windows
2021-11-29 15:41:51 -08:00
Junio C Hamano
ad1260b6c9 Merge branch 'ab/sh-retire-helper-functions'
Make a few helper functions unused and then lose them.

* ab/sh-retire-helper-functions:
  git-sh-setup: remove "sane_grep", it's not needed anymore
  git-sh-setup: remove unused sane_egrep() function
  git-instaweb: unconditionally assume that gitweb is mod_perl capable
  Makefile: remove $(NO_CURL) from $(SCRIPT_DEFINES)
  Makefile: remove $(GIT_VERSION) from $(SCRIPT_DEFINES)
  Makefile: move git-SCRIPT-DEFINES adjacent to $(SCRIPT_DEFINES)
2021-11-29 15:41:50 -08:00
Junio C Hamano
49767c3d9f Merge branch 'tb/plug-pack-bitmap-leaks'
Leakfix.

* tb/plug-pack-bitmap-leaks:
  pack-bitmap.c: more aggressively free in free_bitmap_index()
  pack-bitmap.c: don't leak type-level bitmaps
  midx.c: write MIDX filenames to strbuf
  builtin/multi-pack-index.c: don't leak concatenated options
  builtin/repack.c: avoid leaking child arguments
  builtin/pack-objects.c: don't leak memory via arguments
  t/helper/test-read-midx.c: free MIDX within read_midx_file()
  midx.c: don't leak MIDX from verify_midx_file
  midx.c: clean up chunkfile after reading the MIDX
2021-11-29 15:41:49 -08:00
Junio C Hamano
7c2abf1a83 Merge branch 'tp/send-email-completion'
The command line complation for "git send-email" options have been
tweaked to make it easier to keep it in sync with the command itself.

* tp/send-email-completion:
  send-email docs: add format-patch options
  send-email: programmatically generate bash completions
2021-11-29 15:41:49 -08:00
Junio C Hamano
0ae87432aa Merge branch 'jc/unsetenv-returns-an-int'
The compatibility implementation for unsetenv(3) were written to
mimic ancient, non-POSIX, variant seen in an old glibc; it has been
changed to return an integer to match the more modern era.

* jc/unsetenv-returns-an-int:
  unsetenv(3) returns int, not void
2021-11-29 15:41:48 -08:00
Junio C Hamano
5126145ba8 Merge branch 'jc/fix-ref-sorting-parse'
Things like "git -c branch.sort=bogus branch new HEAD", i.e. the
operation modes of the "git branch" command that do not need the
sort key information, no longer errors out by seeing a bogus sort
key.

* jc/fix-ref-sorting-parse:
  for-each-ref: delay parsing of --sort=<atom> options
2021-11-29 15:41:47 -08:00