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65386 commits

Author SHA1 Message Date
Han-Wen Nienhuys cd2d40fb7f test-ref-store: parse symbolic flag constants
This lets tests use REF_XXXX constants instead of hardcoded integers. The flag
names should be separated by a ','.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:15:18 -08:00
Han-Wen Nienhuys 93db6eef04 test-ref-store: remove force-create argument for create-reflog
Nobody uses force_create=0, so this flag is unnecessary.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:15:18 -08:00
Ævar Arnfjörð Bjarmason eafd6e7e55 object.c: use BUG(...) no die("BUG: ...") in lookup_object_by_type()
Adjust code added in 7463064b28 (object.h: add
lookup_object_by_type() function, 2021-06-22) to use the BUG()
function.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 12:33:58 -08:00
Ævar Arnfjörð Bjarmason a78537a0f2 pathspec: use BUG(...) not die("BUG:%s:%d....", <file>, <line>)
Change code that was added in 8f4f8f4579 (guard against new pathspec
magic in pathspec matching code, 2013-07-14) to use the BUG() macro
instead of emitting a "fatal" message with the "__FILE__"-name and
"__LINE__"-numbers.

The original code predated the existence of the BUG() function, which
was added in d8193743e0 (usage.c: add BUG() function, 2017-05-12).

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 12:31:17 -08:00
Ævar Arnfjörð Bjarmason 46d699f492 strbuf.h: use BUG(...) not die("BUG: ...")
In 7141efab24 (strbuf: clarify assertion in strbuf_setlen(),
2011-04-27) this 'die("BUG: "' invocation was added with the rationale
that strbuf.c had existing users doing the same, but those users were
later changed to use BUG() in 033abf97fc (Replace all die("BUG: ...")
calls by BUG() ones, 2018-05-02). Let's do the same here.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 12:31:16 -08:00
Ævar Arnfjörð Bjarmason 5867757d88 pack-objects: use BUG(...) not die("BUG: ...")
Change this code added in da93d12b00 (pack-objects: be incredibly
anal about stdio semantics, 2006-04-02) to use BUG() instead.

See 1a07e59c3e (Update messages in preparation for i18n, 2018-07-21)
for when the "BUG: " prefix was added, and [1] for background on the
Solaris behavior that prompted the exhaustive error checking in this
fgets() loop.

1. https://lore.kernel.org/git/824.1144007555@lotus.CS.Berkeley.EDU/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 12:31:16 -08:00
Lessley Dennington add4c864b6 blame: enable and test the sparse index
Enable the sparse index for the 'git blame' command. The index was already
not expanded with this command, so the most interesting thing to do is to
add tests that verify that 'git blame' behaves correctly when the sparse
index is enabled and that its performance improves. More specifically, these
cases are:

1. The index is not expanded for 'blame' when given paths in the sparse
checkout cone at multiple levels.

2. Performance measurably improves for 'blame' with sparse index when given
paths in the sparse checkout cone at multiple levels.

The `p2000` tests demonstrate a ~60% execution time reduction when running
'blame' for a file two levels deep and and a ~30% execution time reduction
for a file three levels deep.

Test                                         before  after
----------------------------------------------------------------
2000.62: git blame f2/f4/a (full-v3)         0.31    0.32 +3.2%
2000.63: git blame f2/f4/a (full-v4)         0.29    0.31 +6.9%
2000.64: git blame f2/f4/a (sparse-v3)       0.55    0.23 -58.2%
2000.65: git blame f2/f4/a (sparse-v4)       0.57    0.23 -59.6%
2000.66: git blame f2/f4/f3/a (full-v3)      0.77    0.85 +10.4%
2000.67: git blame f2/f4/f3/a (full-v4)      0.78    0.81 +3.8%
2000.68: git blame f2/f4/f3/a (sparse-v3)    1.07    0.72 -32.7%
2000.99: git blame f2/f4/f3/a (sparse-v4)    1.05    0.73 -30.5%

We do not include paths outside the sparse checkout cone because blame
does not support blaming files that are not present in the working
directory. This is true in both sparse and full checkouts.

Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:55:06 -08:00
Lessley Dennington 51ba65b5c3 diff: enable and test the sparse index
Enable the sparse index within the 'git diff' command. Its implementation
already safely integrates with the sparse index because it shares code
with the 'git status' and 'git checkout' commands that were already
integrated.  For more details see:

d76723ee53 (status: use sparse-index throughout, 2021-07-14)
1ba5f45132 (checkout: stop expanding sparse indexes, 2021-06-29)

The most interesting thing to do is to add tests that verify that 'git
diff' behaves correctly when the sparse index is enabled. These cases are:

1. The index is not expanded for 'diff' and 'diff --staged'
2. 'diff' and 'diff --staged' behave the same in full checkout, sparse
checkout, and sparse index repositories in the following partially-staged
scenarios (i.e. the index, HEAD, and working directory differ at a given
path):
    1. Path is within sparse-checkout cone
    2. Path is outside sparse-checkout cone
    3. A merge conflict exists for paths outside sparse-checkout cone

The `p2000` tests demonstrate a ~44% execution time reduction for 'git
diff' and a ~86% execution time reduction for 'git diff --staged' using a
sparse index:

Test                                      before  after
-------------------------------------------------------------
2000.30: git diff (full-v3)               0.33    0.34 +3.0%
2000.31: git diff (full-v4)               0.33    0.35 +6.1%
2000.32: git diff (sparse-v3)             0.53    0.31 -41.5%
2000.33: git diff (sparse-v4)             0.54    0.29 -46.3%
2000.34: git diff --cached (full-v3)      0.07    0.07 +0.0%
2000.35: git diff --cached (full-v4)      0.07    0.08 +14.3%
2000.36: git diff --cached (sparse-v3)    0.28    0.04 -85.7%
2000.37: git diff --cached (sparse-v4)    0.23    0.03 -87.0%

Co-authored-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:55:06 -08:00
Lessley Dennington 338e2a9acc diff: replace --staged with --cached in t1092 tests
Replace uses of the synonym --staged in t1092 tests with --cached (which
is the real and preferred option). This will allow consistency in the new
tests to be added with the upcoming change to enable the sparse index for
diff.

Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:55:06 -08:00
Lessley Dennington 44c7e62e51 repo-settings: prepare_repo_settings only in git repos
Check whether git directory exists before adding any repo settings. If it
does not exist, BUG with the message that one cannot add settings for an
uninitialized repository. If it does exist, proceed with adding repo
settings.

Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:55:06 -08:00
Lessley Dennington 27a443b820 test-read-cache: set up repo after git directory
Move repo setup to occur after git directory is set up. This will protect
against test failures in the upcoming change to BUG in
prepare_repo_settings if no git directory exists.

Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:55:05 -08:00
Lessley Dennington 0803f9c7cd commit-graph: return if there is no git directory
Return early if git directory does not exist. This will protect against
test failures in the upcoming change to BUG in prepare_repo_settings if no
git directory exists.

Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:55:05 -08:00
Lessley Dennington e5b17bda8b git: ensure correct git directory setup with -h
Ensure correct git directory setup when -h is passed with commands. This
specifically applies to repos with special help text configuration
variables and to commands run with -h outside a repository. This
will also protect against test failures in the upcoming change to BUG in
prepare_repo_settings if no git directory exists.

Note: this diff is better seen when ignoring whitespace changes.

Co-authored-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:55:05 -08:00
Derrick Stolee 8c5de0d265 unpack-trees: use traverse_path instead of name
The sparse_dir_matches_path() method compares a cache entry that is a
sparse directory entry against a 'struct traverse_info *info' and a
'struct name_entry *p' to see if the cache entry has exactly the right
name for those other inputs.

This method was introduced in 523506d (unpack-trees: unpack sparse
directory entries, 2021-07-14), but included a significant mistake. The
path comparisons used 'info->name' instead of 'info->traverse_path'.
Since 'info->name' only stores a single tree entry name while
'info->traverse_path' stores the full path from root, this method does
not work when 'info' is in a subdirectory of a directory. Replacing the
right strings and their corresponding lengths make the method work
properly.

The previous change included a failing test that exposes this issue.
That test now passes. The critical detail is that as we go deep into
unpack_trees(), the logic for merging a sparse directory entry with a
tree entry during 'git checkout' relies on this
sparse_dir_matches_path() in order to avoid calling
traverse_trees_recursive() during unpack_callback() in this hunk:

	if (!is_sparse_directory_entry(src[0], names, info) &&
	    traverse_trees_recursive(n, dirmask, mask & ~dirmask,
					    names, info) < 0) {
		return -1;
	}

For deep paths, the short-circuit never occurred and
traverse_trees_recursive() was being called incorrectly and that was
causing other strange issues. Specifically, the error message from the
now-passing test previously included this:

      error: Your local changes to the following files would be overwritten by checkout:
              deep/deeper1/deepest2/a
              deep/deeper1/deepest3/a
      Please commit your changes or stash them before you switch branches.
      Aborting

These messages occurred because the 'current' cache entry in
twoway_merge() was showing as NULL because the index did not contain
entries for the paths contained within the sparse directory entries. We
instead had 'oldtree' given as the entry at HEAD and 'newtree' as the
entry in the target tree. This led to reject_merge() listing these
paths.

Now that sparse_dir_matches_path() works the same for deep paths as it
does for shallow depths, the rest of the logic kicks in to properly
handle modifying the sparse directory entries as designed.

Reported-by: Gustave Granroth <gus.gran@gmail.com>
Reported-by: Mike Marcelais <michmarc@exchange.microsoft.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:24:54 -08:00
Derrick Stolee 1b38efc7a0 t1092: add deeper changes during a checkout
Extend the repository data in the setup of t1092 to include more
directories within two parent directories. This reproduces a bug found
by users of the sparse index feature with suitably-complicated
sparse-checkout definitions.

Add a failing test that fails in its first 'git checkout deepest' run in
the sparse index case with this error:

  error: Your local changes to the following files would be overwritten by checkout:
          deep/deeper1/deepest2/a
          deep/deeper1/deepest3/a
  Please commit your changes or stash them before you switch branches.
  Aborting

The next change will fix this error, and that fix will make it clear why
the extra depth is necessary for revealing this bug. The assignment of
the sparse-checkout definition to include deep/deeper1/deepest as a
sibling directory is important to ensure that deep/deeper1 is not a
sparse directory entry, but deep/deeper1/deepest2 is.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:24:53 -08:00
Junio C Hamano 91028f7659 grep: clarify what grep.patternType=default means
We documented that with grep.patternType set to default, the "git
grep" command returns to "the default matching behavior" in 84befcd0
(grep: add a grep.patternType configuration setting, 2012-08-03).

The grep.extendedRegexp configuration variable was the only way to
configure the behavior before that, after b22520a3 (grep: allow -E
and -n to be turned on by default via configuration, 2011-03-30)
introduced it.

It is understandable that we referred to the behavior that honors
the older configuration variable as "the default matching"
behavior.  It is fairly clear in its log message:

    When grep.patternType is set to a value other than "default", the
    grep.extendedRegexp setting is ignored. The value of "default" restores
    the current default behavior, including the grep.extendedRegexp
    behavior.

But when the paragraph is read in isolation by a new person who is
not aware of that backstory (which is the synonym for "most users"),
the "default matching behavior" can be read as "how 'git grep'
behaves without any configuration variables or options", which is
"match the pattern as BRE".

Clarify what the passage means by elaborating what the phrase
"default matching behavior" wanted to mean.

Helped-by: Johannes Altmanninger <aclopte@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-05 12:26:43 -08:00
Johannes Schindelin 9f3547837e tests: set GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME only when needed
A couple of test scripts have actually been adapted to accommodate for a
configurable default branch name, but they still overrode it via the
`GIT_TEST_*` variable. Let's drop that override where possible.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-05 11:34:28 -08:00
Elijah Newren 434e0636db sequencer: do not export GIT_DIR and GIT_WORK_TREE for 'exec'
Commands executed from `git rebase --exec` can give different behavior
from within that environment than they would outside of it, due to the
fact that sequencer.c exports both GIT_DIR and GIT_WORK_TREE.  For
example, if the relevant script calls something like

  git -C ../otherdir log --format=%H --no-walk

the user may be surprised to find that the command above does not show a
commit hash from ../otherdir, because $GIT_DIR prevents automatic gitdir
detection and makes the -C option useless.

This is a regression in behavior from the original legacy
implemented-in-shell rebase.  It is perhaps rare for it to cause
problems in practice, especially since most small problems that were
caused by this area of bugs has been fixed-up in the past in a way that
masked the particular bug observed without fixing the real underlying
problem.

An explanation of how we arrived at the current situation is perhaps
merited.  The setting of GIT_DIR and GIT_WORK_TREE done by sequencer.c
arose from a sequence of historical accidents:

* When rebase was implemented as a shell command, it would call
  git-sh-setup, which among other things would set GIT_DIR -- but not
  export it.  This meant that when rebase --exec commands were run via
      /bin/sh -c "$COMMAND"
  they would not inherit the GIT_DIR setting.  The fact that GIT_DIR
  was not set in the run $COMMAND is the behavior we'd like to restore.

* When the rebase--helper builtin was introduced to allow incrementally
  replacing shell with C code, we had an implementation that was half
  shell, half C.  In particular, commit 18633e1a22 ("rebase -i: use the
  rebase--helper builtin", 2017-02-09) added calls to
      exec git rebase--helper ...
  which caused rebase--helper to inherit the GIT_DIR environment
  variable from the shell.  git's setup would change the environment
  variable from an absolute path to a relative one (".git"), but would
  leave it set.  This meant that when rebase --exec commands were run
  via
      run_command_v_opt(...)
  they would inherit the GIT_DIR setting.

* In commit 09d7b6c6fa ("sequencer: pass absolute GIT_DIR to exec
  commands", 2017-10-31), it was noted that the GIT_DIR caused problems
  with some commands; e.g.
      git rebase --exec 'cd subdir && git describe' ...
  would have GIT_DIR=.git which was invalid due to the change to the
  subdirectory.  Instead of questioning why GIT_DIR was set, that commit
  instead made sequencer change GIT_DIR to be an absolute path and
  explicitly export it via
      argv_array_pushf(&child_env, "GIT_DIR=%s", absolute_path(get_git_dir()));
      run_command_v_opt_cd_env(..., child_env.argv)

* In commit ab5e67d751 ("sequencer: pass absolute GIT_WORK_TREE to exec
  commands", 2018-07-14), it was noted that when GIT_DIR is set but
  GIT_WORK_TREE is not, that we do not discover GIT_WORK_TREE but just
  assume it is '.'.  That is incorrect if trying to run commands from a
  subdirectory.  However, rather than question why GIT_DIR was set, that
  commit instead also added GIT_WORK_TREE to the list of things to
  export.

Each of the above problems would have been fixed automatically when
git-rebase became a full builtin, had it not been for the fact that
sequencer.c started exporting GIT_DIR and GIT_WORK_TREE in the interim.
Stop exporting them now.

Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Acked-by: Johannes Altmanninger <aclopte@gmail.com>
Acked-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 23:41:05 -08:00
Elijah Newren 3656f84278 name-rev: prefer shorter names over following merges
name-rev has a MERGE_TRAVERSAL_WEIGHT to say that traversing a second or
later parent of a merge should be 65535 times more expensive than a
first-parent traversal, as per ac076c29ae (name-rev: Fix non-shortest
description, 2007-08-27).  The point of this weight is to prefer names
like

    v2.32.0~1471^2

over names like

    v2.32.0~43^2~15^2~11^2~20^2~31^2

which are two equally valid names in git.git for the same commit.  Note
that the first follows 1472 parent traversals compared to a mere 125 for
the second.  Weighting all traversals equally would clearly prefer the
second name since it has fewer parent traversals, but humans aren't
going to be traversing commits and they tend to have an easier time
digesting names with fewer segments.  The fact that the former only has
two segments (~1471, ^2) makes it much simpler than the latter which has
six segments (~43, ^2, ~15, etc.).  Since name-rev is meant to "find
symbolic names suitable for human digestion", we prefer fewer segments.

However, the particular rule implemented in name-rev would actually
prefer

    v2.33.0-rc0~11^2~1

over

    v2.33.0-rc0~20^2

because both have precisely one second parent traversal, and it gives
the tie breaker to shortest number of total parent traversals.  Fewer
segments is more important for human consumption than number of hops, so
we'd rather see the latter which has one fewer segment.

Include the generation in is_better_name() and use a new
effective_distance() calculation so that we prefer fewer segments in
the printed name over fewer total parent traversals performed to get the
answer.

== Side-note on tie-breakers ==

When there are the same number of segments for two different names, we
actually use the name of an ancestor commit as a tie-breaker as well.
For example, for the commit cbdca289fb in the git.git repository, we
prefer the name v2.33.0-rc0~112^2~1 over v2.33.0-rc0~57^2~5.  This is
because:

  * cbdca289fb is the parent of 25e65b6dd5, which implies the name for
    cbdca289fb should be the first parent of the preferred name for
    25e65b6dd5
  * 25e65b6dd5 could be named either v2.33.0-rc0~112^2 or
    v2.33.0-rc0~57^2~4, but the former is preferred over the latter due
    to fewer segments
  * combine the two previous facts, and the name we get for cbdca289fb
    is "v2.33.0-rc0~112^2~1" rather than "v2.33.0-rc0~57^2~5".

Technically, we get this for free out of the implementation since we
only keep track of one name for each commit as we walk history (and
re-add parents to the queue if we find a better name for those parents),
but the first bullet point above ensures users get results that feel
more consistent.

== Alternative Ideas and Meanings Discussed ==

One suggestion that came up during review was that shortest
string-length might be easiest for users to consume.  However, such a
scheme would be rather computationally expensive (we'd have to track all
names for each commit as we traversed the graph) and would additionally
come with the possibly perplexing result that on a linear segment of
history we could rapidly swap back and forth on names:
   MYTAG~3^2     would     be preferred over   MYTAG~9998
   MYTAG~3^2~1   would NOT be preferred over   MYTAG~9999
   MYTAG~3^2~2   might     be preferred over   MYTAG~10000

Another item that came up was possible auxiliary semantic meanings for
name-rev results either before or after this patch.  The basic answer
was that the previous implementation had no known useful auxiliary
semantics, but that for many repositories (most in my experience), the
new scheme does.  In particular, the new name-rev output can often be
used to answer the question, "How or when did this commit get merged?"
Since that usefulness depends on how merges happen within the repository
and thus isn't universally applicable, details are omitted here but you
can see them at [1].

[1] https://lore.kernel.org/git/CABPp-BEeUM+3NLKDVdak90_UUeNghYCx=Dgir6=8ixvYmvyq3Q@mail.gmail.com/

Finally, it was noted that the algorithm could be improved by just
explicitly tracking the number of segments and using both it and
distance in the comparison, instead of giving a magic number that tries
to blend the two (and which therefore might give suboptimal results in
repositories with really huge numbers of commits that periodically merge
older code).  However, "[this patch] seems to give us a much better
results than the current code, so let's take it and leave further
futzing outside the scope."

Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 23:39:34 -08:00
Jeff King 1e45db1214 xdiff: drop unused flags parameter from recs_match
Since 6b13bc3232 (xdiff: simplify comparison, 2021-11-17), we do not
call xdl_recmatch() from xdiffi.c's recs_match(), so we no longer need
the "flags" parameter. That in turn lets us drop the flags parameters
from the group-slide functions which call it.

There's no functional change here; it's just making these functions a
little simpler.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 23:27:53 -08:00
Jeff King 25449450c0 xdiff: drop xpparam_t parameter from histogram cmp_recs()
Since 663c5ad035 (diff histogram: intern strings, 2021-11-17), our
cmp_recs() does not call xdl_recmatch(), and thus no longer needs an
xpparam_t struct from which to get the flags. We can drop the unused
parameter from the function, as well as the macro which wraps it.

There's no functional change here; it's just simplifying things (and
making -Wunused-parameter happier).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 23:27:53 -08:00
Jeff King cf0b26d90c xdiff: drop CMP_ENV macro from xhistogram
This macro has been unused since 43ca7530df (xdiff/xhistogram: rely on
xdl_trim_ends(), 2011-08-01). The function that called it went away
there, and its use in the CMP() macro was inlined. It probably should
have been deleted then, but nobody noticed.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 23:27:53 -08:00
Eric Sunshine b50252484f git-worktree.txt: add missing -v to synopsis for worktree list
When verbose mode was added to `git worktree list` by 076b444a62
(worktree: teach `list` verbose mode, 2021-01-27), although the
documentation was updated to reflect the new functionality, the
synopsis was overlooked. Correct this minor oversight.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 23:27:25 -08:00
Eric Sunshine da8fb6be55 worktree: send "chatty" messages to stderr
The order in which the stdout and stderr streams are flushed is not
guaranteed to be the same across platforms or `libc` implementations.
This lack of determinism can lead to anomalous and potentially confusing
output if normal (stdout) output is flushed after error (stderr) output.
For instance, the following output which clearly indicates a failure due
to a fatal error:

    % git worktree add ../foo bar
    Preparing worktree (checking out 'bar')
    fatal: 'bar' is already checked out at '.../wherever'

has been reported[1] on Microsoft Windows to appear as:

    % git worktree add ../foo bar
    fatal: 'bar' is already checked out at '.../wherever'
    Preparing worktree (checking out 'bar')

which may confuse the reader into thinking that the command somehow
recovered and ran to completion despite the error.

This problem crops up because the "chatty" status message "Preparing
worktree" is sent to stdout, whereas the "fatal" error message is sent
to stderr. One way to fix this would be to flush stdout manually before
git-worktree reports any errors to stderr.

However, common practice in Git is for "chatty" messages to be sent to
stderr. Therefore, a more appropriate fix is to adjust git-worktree to
conform to that practice by sending its "chatty" messages to stderr
rather than stdout as is currently the case.

There may be concern that relocating messages from stdout to stderr
could break existing tooling, however, these messages are already
internationalized, thus are unstable. And, indeed, the "Preparing
worktree" message has already been the subject of somewhat significant
changes in 2c27002a0a (worktree: improve message when creating a new
worktree, 2018-04-24). Moreover, there is existing precedent, such as
68b939b2f0 (clone: send diagnostic messages to stderr, 2013-09-18) which
likewise relocated "chatty" messages from stdout to stderr for
git-clone.

[1]: https://lore.kernel.org/git/CA+34VNLj6VB1kCkA=MfM7TZR+6HgqNi5-UaziAoCXacSVkch4A@mail.gmail.com/T/

Reported-by: Baruch Burstein <bmburstein@gmail.com>
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 23:27:11 -08:00
Taylor Blau 0bf0de6cc7 packfile: make close_pack_revindex() static
Since its definition in 2f4ba2a867 (packfile: prepare for the existence
of '*.rev' files, 2021-01-25), the only caller of
`close_pack_revindex()` was within packfile.c.

Thus there is no need for this to be exposed via packfile.h, and instead
can remain static within packfile.c's compilation unit. While we're
here, move the function's opening brace onto its own line.

Noticed-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 23:01:38 -08:00
Johannes Schindelin ddc35d833d scalar: implement the version command
The .NET version of Scalar has a `version` command. This was necessary
because it was versioned independently of Git.

Since Scalar is now tightly coupled with Git, it does not make sense for
them to show different versions. Therefore, it shows the same output as
`git version`. For backwards-compatibility with the .NET version,
`scalar version` prints to `stderr`, though (`git version` prints to
`stdout` instead).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:24 -08:00
Matthew John Cheetham d85ada7cbd scalar: implement the delete command
Delete an enlistment by first unregistering the repository and then
deleting the enlistment directory (usually the directory containing the
worktree `src/` directory).

On Windows, if the current directory is inside the enlistment's
directory, change to the parent of the enlistment directory, to allow us
to delete the enlistment (directories used by processes e.g. as current
working directories cannot be deleted on Windows).

Co-authored-by: Victoria Dye <vdye@github.com>
Signed-off-by: Matthew John Cheetham <mjcheetham@outlook.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:24 -08:00
Johannes Schindelin 4582676075 scalar: teach 'reconfigure' to optionally handle all registered enlistments
After a Scalar upgrade, it can come in really handy if there is an easy
way to reconfigure all Scalar enlistments. This new option offers this
functionality.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:24 -08:00
Johannes Schindelin cb59d55ec1 scalar: allow reconfiguring an existing enlistment
This comes in handy during Scalar upgrades, or when config settings were
messed up by mistake.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:24 -08:00
Derrick Stolee 7020c88c30 scalar: implement the run command
Note: this subcommand is provided primarily for backwards-compatibility,
for existing Scalar uses. It is mostly just a shim for `git
maintenance`, mapping task names from the way Scalar called them to the
way Git calls them.

The reason why those names differ? The background maintenance was first
implemented in Scalar, and when it was contributed as a patch series
implementing the `git maintenance` command, reviewers suggested better
names, those suggestions were accepted before the patches were
integrated into core Git.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:24 -08:00
Johannes Schindelin 4368e40bef scalar: teach 'clone' to support the --single-branch option
Just like `git clone`, the `scalar clone` command now also offers to
restrict the clone to a single branch.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:24 -08:00
Johannes Schindelin 546f822d53 scalar: implement the clone subcommand
This implements Scalar's opinionated `clone` command: it tries to use a
partial clone and sets up a sparse checkout by default. In contrast to
`git clone`, `scalar clone` sets up the worktree in the `src/`
subdirectory, to encourage a separation between the source files and the
build output (which helps Git tremendously because it avoids untracked
files that have to be specifically ignored when refreshing the index).

Also, it registers the repository for regular, scheduled maintenance,
and configures a flurry of configuration settings based on the
experience and experiments of the Microsoft Windows and the Microsoft
Office development teams.

Note: since the `scalar clone` command is by far the most commonly
called `scalar` subcommand, we document it at the top of the manual
page.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:23 -08:00
Derrick Stolee 2b7104573c scalar: implement 'scalar list'
The produced list simply consists of those repositories registered under
the multi-valued `scalar.repo` config setting in the user's Git config.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:23 -08:00
Johannes Schindelin f5f0842d0b scalar: let 'unregister' handle a deleted enlistment directory gracefully
When a user deleted an enlistment manually, let's be generous and
_still_ unregister it.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:23 -08:00
Derrick Stolee c76a53eb71 scalar: 'unregister' stops background maintenance
Just like `scalar register` starts the scheduled background maintenance,
`scalar unregister` stops it. Note that we use `git maintenance start`
in `scalar register`, but we do not use `git maintenance stop` in
`scalar unregister`: this would stop maintenance for _all_ repositories,
not just for the one we want to unregister.

The `unregister` command also removes the corresponding entry from the
`[scalar]` section in the global Git config.

Co-authored-by: Victoria Dye <vdye@github.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:23 -08:00
Derrick Stolee d0feac4e8c scalar: 'register' sets recommended config and starts maintenance
Let's start implementing the `register` command. With this commit,
recommended settings are configured upon `scalar register`, and Git's
background maintenance is started.

The recommended config settings may very well change in the future. For
example, once the built-in FSMonitor is available, we will want to
enable it upon `scalar register`. For that reason, we explicitly support
running `scalar register` in an already-registered enlistment.

Co-authored-by: Victoria Dye <vdye@github.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:23 -08:00
Johannes Schindelin 9187659f9a scalar: create test infrastructure
To test the Scalar command, create a test script in contrib/scalar/t
that is executed as `make -C contrib/scalar test`. Since Scalar has no
meaningful capabilities yet, the only test is rather simple. We will add
more tests in subsequent commits that introduce corresponding, new
functionality.

Note: This test script is intended to test `scalar` only lightly, even
after all of the functionality is implemented.

A more comprehensive functional (or: integration) test suite can be
found at https://github.com/microsoft/scalar; It is used in the workflow
https://github.com/microsoft/git/blob/HEAD/.github/workflows/scalar-functional-tests.yml
in Microsoft's Git fork. This test suite performs end-to-end tests with
a real remote repository, and is run as part of the regular CI and PR
builds in that fork.

Since those tests require some functionality supported only by
Microsoft's Git fork ("GVFS protocol"), there is no intention to port
that fuller test suite to `contrib/scalar/`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:23 -08:00
Johannes Schindelin 829fe56c62 scalar: start documenting the command
Let's build up the documentation for the Scalar command along with the
patches that implement its functionality.

Note: To discourage the feature-incomplete documentation from being
mistaken for the complete thing, we do not yet provide any way to build
HTML or manual pages from the text file.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:23 -08:00
Johannes Schindelin 0a43fb2202 scalar: create a rudimentary executable
The idea of Scalar (https://github.com/microsoft/scalar), and before
that, of VFS for Git, has always been to prove that Git _can_ scale, and
to upstream whatever strategies have been demonstrated to help.

With this patch, we start the journey from that C# project to move what
is left to Git's own `contrib/` directory, reimplementing it in pure C,
with the intention to facilitate integrating the functionality into core
Git all while maintaining backwards-compatibility for existing Scalar
users (which will be much easier when both live in the same worktree).
It has always been the plan to contribute all of the proven strategies
back to core Git.

For example, while the virtual filesystem provided by VFS for Git helped
the team developing the Windows operating system to move onto Git, while
trying to upstream it we realized that it cannot be done: getting the
virtual filesystem to work (which we only managed to implement fully on
Windows, but not on, say, macOS or Linux), and the required server-side
support for the GVFS protocol, made this not quite feasible.

The Scalar project learned from that and tackled the problem with
different tactics: instead of pretending to Git that the working
directory is fully populated, it _specifically_ teaches Git about
partial clone (which is based on VFS for Git's cache server), about
sparse checkout (which VFS for Git tried to do transparently, in the
file system layer), and regularly runs maintenance tasks to keep the
repository in a healthy state.

With partial clone, sparse checkout and `git maintenance` having been
upstreamed, there is little left that `scalar.exe` does which `git.exe`
cannot do. One such thing is that `scalar clone <url>` will
automatically set up a partial, sparse clone, and configure
known-helpful settings from the start.

So let's bring this convenience into Git's tree.

The idea here is that you can (optionally) build Scalar via

	make -C contrib/scalar/

This will build the `scalar` executable and put it into the
contrib/scalar/ subdirectory.

The slightly awkward addition of the `contrib/scalar/*` bits to the
top-level `Makefile` are actually really required: we want to link to
`libgit.a`, which means that we will need to use the very same `CFLAGS`
and `LDFLAGS` as the rest of Git.

An early development version of this patch tried to replicate all the
conditional code in `contrib/scalar/Makefile` (e.g. `NO_POLL`) just like
`contrib/svn-fe/Makefile` used to do before it was retired. It turned
out to be quite the whack-a-mole game: the SHA-1-related flags, the
flags enabling/disabling `compat/poll/`, `compat/regex/`,
`compat/win32mmap.c` & friends depending on the current platform... To
put it mildly: it was a major mess.

Instead, this patch makes minimal changes to the top-level `Makefile` so
that the bits in `contrib/scalar/` can be compiled and linked, and
adds a `contrib/scalar/Makefile` that uses the top-level `Makefile` in a
most minimal way to do the actual compiling.

Note: With this commit, we only establish the infrastructure, no
Scalar functionality is implemented yet; We will do that incrementally
over the next few commits.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:23 -08:00
Johannes Schindelin cd5a9ac080 scalar: add a README with a roadmap
The Scalar command will be contributed incrementally, over a bunch of
patch series. Let's document what Scalar is about, and then describe the
patch series that are planned.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 21:52:23 -08:00
Eric Sunshine e258eb4800 CodingGuidelines: document which output goes to stdout vs. stderr
It has long been practice on this project for a command to emit its
primary output to stdout so that it can be captured to a file or sent
down a pipe, and to emit "chatty" messages (such as those reporting
progress) to stderr so that they don't interfere with the primary
output. However, this practice is not necessarily universal; another
common practice is to send only error messages to stderr, and all other
messages to stdout. Therefore, help newcomers out by documenting how
stdout and stderr are used on this project.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-04 17:26:41 -08:00
Junio C Hamano 44ba10d671 revision: use C99 declaration of variable in for() loop
There are certain C99 features that might be nice to use in our code
base, but we've hesitated to do so in order to avoid breaking
compatibility with older compilers. But we don't actually know if
people are even using pre-C99 compilers these days.

One way to figure that out is to introduce a very small use of a
feature, and see if anybody complains, and we've done so to probe
the portability for a few features like "trailing comma in enum
declaration", "designated initializer for struct", and "designated
initializer for array".  A few years ago, we tried to use a handy

    for (int i = 0; i < n; i++)
	use(i);

to introduce a new variable valid only in the loop, but found that
some compilers we cared about didn't like it back then.  Two years
is a long-enough time, so let's try it again.

If this patch can survive a few releases without complaint, then we
can feel more confident that variable declaration in for() loop is
supported by the compilers our user base use.  And if we do get
complaints, then we'll have gained some data and we can easily
revert this patch.

Helped-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-03 10:16:00 -08:00
Han-Wen Nienhuys 65279256f3 refs/debug: trim trailing LF from reflog message
On iteration, the reflog message is always terminated by a newline. Trim it to
avoid clobbering the console with is this extra newline.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-02 11:14:08 -08:00
Han-Wen Nienhuys 3474b602a5 test-ref-store: tweaks to for-each-reflog-ent format
We have some tests that read from files in .git/logs/ hierarchy
when checking if correct reflog entries are created, but that is
too specific to the files backend.  Other backends like reftable
may not store its reflog entries in such a "one line per entry"
format.

Update for-each-reflog-ent test helper to produce output that
is identical to lines in a reflog file files backend uses.
That way, (1) the current tests can be updated to use the test
helper to read the reflog entries instead of (parts of) reflog
files, and perform the same inspection for correctness, and (2)
when the ref backend is swapped to another backend, the updated
test can be used as-is to check the correctness.

Adapt t1400 to use the for-each-reflog-ent test helper.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-02 11:14:08 -08:00
Han-Wen Nienhuys 6887f69faa t1405: check for_each_reflog_ent_reverse() more thoroughly
If we are checking for a certain ordering, we should check that there are two
entries. Do this by mirroring the preceding test.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-02 11:14:08 -08:00
Han-Wen Nienhuys 21f0e85061 test-ref-store: don't add newline to reflog message
By convention, reflog messages always end in '\n', so
before we would print blank lines between entries.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-02 11:14:07 -08:00
Han-Wen Nienhuys f2463490c4 show-branch: show reflog message
Before, --reflog option would look for '\t' in the reflog message. As refs.c
already parses the reflog line, the '\t' was never found, and show-branch
--reflog would always say "(none)" as reflog message

Add test.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-02 11:14:07 -08:00
Jeff King be73860793 log: load decorations with --simplify-by-decoration
It's possible to specify --simplify-by-decoration but not --decorate. In
this case we do respect the simplification, but we don't actually show
any decorations. However, it works by lazy-loading the decorations when
needed; this is discussed in more detail in 0cc7380d88 (log-tree: call
load_ref_decorations() in get_name_decoration(), 2019-09-08).

This works for basic cases, but will fail to respect any --decorate-refs
option (or its variants). Those are handled only when cmd_log_init()
loads the ref decorations up front, which is only when --decorate is
specified explicitly (or as of the previous commit, when the userformat
asks for %d or similar).

We can solve this by making sure to load the decorations if we're going
to simplify using them but they're not otherwise going to be displayed.

The new test shows a simple case that fails without this patch. Note
that we expect two commits in the output: the one we asked for by
--decorate-refs, and the initial commit. The latter is just a quirk of
how --simplify-by-decoration works. Arguably it may be a bug, but it's
unrelated to this patch (which is just about the loading of the
decorations; you get the same behavior before this patch with an
explicit --decorate).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-01 23:10:50 -08:00
Jeff King 14b9c2b3e3 log: handle --decorate-refs with userformat "%d"
In order to show ref decorations, we first have to load them. If you
run:

  git log --decorate

then git-log will recognize the option and load them up front via
cmd_log_init(). Likewise if log.decorate is set.

If you don't say --decorate explicitly, but do mention "%d" or "%D" in
the output format, like so:

  git log --format=%d

then this also works, because we lazy-load the ref decorations. This has
been true since 3b3d443feb (add '%d' pretty format specifier to show
decoration, 2008-09-04), though the lazy-load was later moved into
log-tree.c.

But there's one problem: that lazy-load just uses the defaults; it
doesn't take into account any --decorate-refs options (or its exclude
variant, or their config). So this does not work:

  git log --decorate-refs=whatever --format=%d

It will decorate using all refs, not just the specified ones. This has
been true since --decorate-refs was added in 65516f586b (log: add option
to choose which refs to decorate, 2017-11-21). Adding further confusion
is that it _may_ work because of the auto-decoration feature. If that's
in use (and it often is, as it's the default), then if the output is
going to stdout, we do enable decorations early (and so load them up
front, respecting the extra options). But otherwise we do not. So:

  git log --decorate-refs=whatever --format=%d >some-file

would typically behave differently than it does when the output goes to
the pager or terminal!

The solution is simple: we should recognize in cmd_log_init() that we're
going to show decorations, and make sure we load them there. We already
check userformat_find_requirements(), so we can couple this with our
existing code there.

There are two new tests. The first shows off the actual fix. The second
makes sure that our fix doesn't cause us to stomp on an existing
--decorate option (see the new comment in the code, as well).

Reported-by: Josh Rampersad <josh.rampersad@voiceflow.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-01 22:58:46 -08:00
Anders Kaseorg 593a2a5d06 branch: protect branches checked out in all worktrees
Refuse to force-move a branch over the currently checked out branch of
any working tree, not just the current one.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-01 22:18:25 -08:00