Since many users like to learn from examples, provide a section in the
manual with example commands that would be used and a brief explanation
of what each does.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
With cone mode as the default, it makes sense to discuss it before
non-cone mode. Also, the new default means we can just use directories
in most cases and users do not need to understand patterns or their
meanings. Let's take advantage of this to mark several sections as
"INTERNALS", notifying the user that they do not need to know all those
details in order to make use of the sparse-checkout command.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The 'init' subcommand of sparse-checkout was deprecated in ba2f3f58ac
("git-sparse-checkout.txt: update to document init/set/reapply changes",
2021-12-14), but a couple places in the manual still assumed it was the
primary way to use sparse-checkout. Correct them.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that cone mode is the default, we'd like to focus on the arguments
to set/add being directories rather than patterns, and it probably makes
sense to provide an earlier heads up that files from leading directories
get included as well.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make cone mode the default, and update the documentation accordingly.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add an explicit --no-cone to several sparse-checkout invocations in
preparation for changing the default to cone mode.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When "--current" is given to "git show-branch" running in the
"--reflog" mode, the code tries to reference a "reflog" message
that does not even exist. This is because the --current is not
prepared to work in that mode.
The reason "--current" exists is to support this request:
I list branches on the command line. These are the branchesI
care about and I use as anchoring points. I may or may not be on
one of these main branches. Please make sure I can view the
commits on the current branch with respect to what is in these
other branches.
And to serve that request, the code checks if the current branch is
among the ones listed on the command line, and adds it only if it is
not to the end of one array, which essentially lists the objects.
The reflog mode additionally uses another array to list reflog
messages, which the "--current" code does not add to. This leaves
one uninitialized slot at the end of the array of reflog messages,
and causes the program to show garbage or segfault.
Catch the unsupported (and meaningless) combination and exit with a
usage error.
There are other combinations of options that are incompatible but
have not been tested. Add test to cover them while adding coverage
for this new combination.
Reported-by: Gregory David <gregory.david@p1sec.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This document gathers tips, scripts and configuration file to help
people working on Git’s codebase use their favorite tools while
following Git’s coding style.
Move the part about Emacs configuration from CodingGuidelines to
ToolsForGit.txt because it's the purpose of the new file centralize the
information about tools.
But, add a mention to Documentation/ToolsForGit.txt in CodingGuidelines
because there is also information about the coding style in it.
Helped-by: Matthieu Moy <Matthieu.Moy@univ-lyon1.fr>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: COGONI Guillaume <cogoni.guillaume@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
--keep-base rebases onto the merge base of the given upstream and the
current HEAD regardless of whether a branch is given. This is contrary
to the documentation and to the option's intended purpose. Instead,
rebase onto the merge base of the given upstream and the given branch.
Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git uses temporary files to pass the contents of blobs to external diff
programs and textconv filters. It calls mks_tempfile_ts() to create
them, which puts them all in the same directory. This requires adding
a random name prefix.
Use mks_tempfile_dt() instead, which allows the files to have arbitrary
names, each in their own separate temporary directory. This way they
can have the same basename as the original blob, which looks nicer in
graphical diff programs.
The test in t4020 to check the prettiness of the temporary paths was
neutered by 5476bdf0e8 (diff tests: don't ignore "git diff" exit code in
"read" loop, 2022-03-07), which removed its grep check without replacing
it with an equivalent test_cmp check. Add one that only checks the
basename of the temporary file and nothing else.
And make the test more robust while at it, by using test_when_finished
to get rid of the added file even if the test fails.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a function to create a temporary file with a certain name in a
temporary directory created using mkdtemp(3). Its result is more
sightly than the paths created by mks_tempfile_ts(), which include
a random prefix. That's useful for files passed to a program that
displays their name, e.g. an external diff tool.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are two reasons that we could return NULL early within
load_commit_graph_chain():
1. The file does not exist, so the file pointer is NULL.
2. The file exists, but is too small to contain a single hash.
These were grouped together when the function was first written in
5c84b3396 (commit-graph: load commit-graph chains, 2019-06-18) in order
to simplify how the 'chain_name' string is freed. However, the current
code leaves a narrow window where the file pointer is not closed when
the file exists, but is rejected for being too small.
Split out these cases separately to ensure we close the file in this
case.
Signed-off-by: Kleber Tarcísio <klebertarcisio@yahoo.com.br>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There is an if statement where both if and else have the same
assignment of options.type to REBASE_MERGE. Simplify
it by getting that assigmnent out of the if.
Signed-off-by: Edmundo Carmona Antoranz <eantoranz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A couple of work around for CI breaking warnings from gcc 12.
* cb/buggy-gcc-12-workaround:
config.mak.dev: alternative workaround to gcc 12 warning in http.c
config.mak.dev: workaround gcc 12 bug affecting "pedantic" CI job
This provides a "no code change needed" option to the "fix" currently
queued as part of ab/http-gcc-12-workaround and therefore should be
reverted once that gets merged.
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Originally noticed by Peff[1], but yet to be corrected[2] and planned to
be released with Fedora 36 (scheduled for Apr 19).
dir.c: In function ‘git_url_basename’:
dir.c:3085:13: error: ‘memchr’ specified bound [9223372036854775808, 0] exceeds maximum object size 9223372036854775807 [-Werror=stringop-overread]
3085 | if (memchr(start, '/', end - start) == NULL
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fedora is used as part of the CI, and therefore that release will trigger
failures, unless the version of the image used is locked to an older
release, as an alternative.
Restricting the flag to the affected source file, as well as implementing
an independent facility to track these workarounds was specifically punted
to minimize the risk of introducing problems so close to a release.
This change should be reverted once the underlying gcc bug is solved and
which should be visible by NOT triggering a warning, otherwise.
[1] https://lore.kernel.org/git/YZQhLh2BU5Hquhpo@coredump.intra.peff.net/
[2] https://bugzilla.redhat.com/show_bug.cgi?id=2075786
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1214aa841b (reftable: add blocksource, an abstraction for random
access reads, 2021-10-07), makes the assumption that it is ok to
free a reftable_block pointing to NULL if the size is also set to
0, but implements that using a memset call that at least in glibc
based system will trigger a runtime exception if called with a
NULL pointer as its first parameter.
Avoid doing so by adding a conditional to check for the size in all
three identically looking functions that were affected, and therefore,
still allow memset to help catch callers that might incorrectly pass
a NULL pointer with a non zero size, but avoiding the exception for
the valid cases.
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Revert the "deletion of a ref should not trigger transaction events
for loose and packed ref backends separately" that regresses the
behaviour when a ref is not modified since it was packed.
* jc/revert-ref-transaction-hook-changes:
RelNotes: revert the description on the reverted topics
Revert "fetch: increase test coverage of fetches"
Revert "Merge branch 'ps/avoid-unnecessary-hook-invocation-with-packed-refs'"
* update the following words translations: commit, untracked, stage,
cache, stash, work..., index, reset, label, check..., tags, graft,
alternate object, amend, ancestor, cherry-pick, bisect, blame, chain,
cache, bug, chunk, branch, bundle, clean, clone, commit-graph, commit
object, commit-ish, committer, cover letter, conflict, dangling,
detach, dir, dumb, fast-forward, file system, fixup, fork, fetch, Git
archive, gitdir, graft, replace ref
* correct some mispellings
* git-po-helper update
* remove some obsolete lines
* unfuzzy entries
* random translation updates
* update contact in pt_PT.po
* add the following words to the translation table: override, recurse,
print, offset, unbundle, mirror repository, multi-pack, bad,
whitespace, batch
* remove the following words of the translation table: core Git
* change the following words on the translation table: dry-run, apply,
patch, replay, blame, chain, gitdir, file system, fork, unset, handle
* some translation to the first person
* update copyright text
* word 'utilização:' to 'uso:'
* word 'pai' to 'parente'
Signed-off-by: Daniel Santos <dacs.git@brilhante.top>
Add a TODO comment indicating that we should release "diffopt" in
release_revisions(). In a preceding commit we started releasing the
"pruning" member of the same type, but handling "diffopt" will require
us to untangle the "no_free" conditions I added in e900d494dc (diff:
add an API for deferred freeing, 2021-02-11).
Let's leave a TODO comment to that effect, and so that we don't forget
refactor code that was changed to use release_revisions() in earlier
commits to stop using the "diffopt" member after a call to
release_revisions(). This works currently, but would become a logic
error as soon as we started freeing "diffopt". Doing that change now
doesn't harm anything, and future-proofs us against a later change to
release_revisions().
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Refactor the existing reset_topo_walk() into a thin wrapper for a
release_revisions_topo_walk_info() + resetting the member to "NULL",
and call release_revisions_topo_walk_info() from release_revisions().
This fixes memory leaks that have been with us ever since
"topo_walk_info" was added to revision.[ch] in
f0d9cc4196 (revision.c: begin refactoring --topo-order logic,
2018-11-01).
Due to various other leaks this makes no tests pass in their entirety,
but e.g. before this running this on git.git:
./git -P log --pretty=tformat:"%P %H | %s" --parents --full-history --topo-order -3 -- README.md
Would report under SANITIZE=leak:
SUMMARY: LeakSanitizer: 531064 byte(s) leaked in 6 allocation(s).
Now we'll free all of that memory.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Extend the the release_revisions() function so that it frees the
"date_mode" in the "struct ref_info".
This uses the date_mode_release() function added in 974c919d36 (date
API: add and use a date_mode_release(), 2022-02-16). As that commit
notes "t7004-tag.sh" tests for the leaks that are being fixed
here. That test now fails "only" 44 tests, instead of the 46 it failed
before this change.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Call diff_free() on the "pruning" member of "struct rev_info". Doing
so makes several tests pass under SANITIZE=leak.
This was also the last missing piece that allows us to remove the
UNLEAK() in "cmd_diff" and "cmd_diff_index", which allows us to use
those commands as a canary for general leaks in the revisions API. See
[1] for further rationale, and 886e1084d7 (builtin/: add UNLEAKs,
2017-10-01) for the commit that added the UNLEAK() there.
1. https://lore.kernel.org/git/220218.861r00ib86.gmgdl@evledraar.gmail.com/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a missing reflog_walk_info_release() to "reflog-walk.c" and use it
in release_revisions().
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Clear the "boundary_commits" object_array in release_revisions(). This
makes a few more tests pass under SANITIZE=leak, including
"t/t4126-apply-empty.sh" which started failed as an UNLEAK() in
cmd_format_patch() was removed in a preceding commit.
This also re-marks the various tests relying on "git format-patch" as
passing under "SANITIZE=leak", in the preceding "revisions API users:
use release_revisions() in builtin/log.c" commit those were marked as
failing as we removed the UNLEAK(rev) from cmd_format_patch() in
"builtin/log.c".
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Extend the the release_revisions() function so that it frees the
"prune_data" in the "struct rev_info". This means that any code that
calls "release_revisions()" already can get rid of adjacent calls to
clear_pathspec().
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Extend the the release_revisions() function so that it frees the
"grep_filter" in the "struct rev_info".This allows us to mark a test
as passing under "TEST_PASSES_SANITIZE_LEAK=true".
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Extend the the release_revisions() function so that it frees the
"filter" in the "struct rev_info". This in combination with a
preceding change to free "cmdline" means that we can mark another set
of tests as passing under "TEST_PASSES_SANITIZE_LEAK=true".
The "filter" member was added recently in ffaa137f64 (revision: put
object filter into struct rev_info, 2022-03-09), and this fixes leaks
intruded in the subsequent leak 7940941de1 (pack-objects: use
rev.filter when possible, 2022-03-09) and 105c6f14ad (bundle: parse
filter capability, 2022-03-09).
The "builtin/pack-objects.c" leak in 7940941de1 was effectively with
us already, but the variable was referred to by a "static" file-scoped
variable. The "bundle.c " leak in 105c6f14ad was newly introduced
with the new "filter" feature for bundles.
The "t5600-clone-fail-cleanup.sh" change here to add
"TEST_PASSES_SANITIZE_LEAK=true" is one of the cases where
run-command.c in not carrying the abort() exit code upwards would have
had that test passing before, but now it *actually* passes[1]. We
should fix the lack of 1=1 mapping of SANITIZE=leak testing to actual
leaks some other time, but it's an existing edge case, let's just mark
the really-passing test as passing for now.
1. https://lore.kernel.org/git/220303.86fsnz5o9w.gmgdl@evledraar.gmail.com/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Extend the the release_revisions() function so that it frees the
"cmdline" in the "struct rev_info". This in combination with a
preceding change to free "commits" and "mailmap" means that we can
whitelist another test under "TEST_PASSES_SANITIZE_LEAK=true".
There was a proposal in [1] to do away with xstrdup()-ing this
add_rev_cmdline(), perhaps that would be worthwhile, but for now let's
just free() it.
We could also make that a "char *" in "struct rev_cmdline_entry"
itself, but since we own it let's expose it as a constant to outside
callers. I proposed that in [2] but have since changed my mind. See
14d30cdfc0 (ref-filter: fix memory leak in `free_array_item()`,
2019-07-10), c514c62a4f (checkout: fix leak of non-existent branch
names, 2020-08-14) and other log history hits for "free((char *)" for
prior art.
This includes the tests we had false-positive passes on before my
6798b08e84 (perl Git.pm: don't ignore signalled failure in
_cmd_close(), 2022-02-01), now they pass for real.
Since there are 66 tests matching t/t[0-9]*git-svn*.sh it's easier to
list those that don't pass than to touch most of those 66. So let's
introduce a "TEST_FAILS_SANITIZE_LEAK=true", which if set in the tests
won't cause lib-git-svn.sh to set "TEST_PASSES_SANITIZE_LEAK=true.
This change also marks all the tests that we removed
"TEST_FAILS_SANITIZE_LEAK=true" from in an earlier commit due to
removing the UNLEAK() from cmd_format_patch(), we can now assert that
its API use doesn't leak any "struct rev_info" memory.
This change also made commit "t5503-tagfollow.sh" pass on current
master, but that would regress when combined with
ps/fetch-atomic-fixup's de004e848a (t5503: simplify setup of test
which exercises failure of backfill, 2022-03-03) (through no fault of
that topic, that change started using "git clone" in the test, which
has an outstanding leak). Let's leave that test out for now to avoid
in-flight semantic conflicts.
1. https://lore.kernel.org/git/YUj%2FgFRh6pwrZalY@carlos-mbp.lan/
2. https://lore.kernel.org/git/87o88obkb1.fsf@evledraar.gmail.com/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Extend the the release_revisions() function so that it frees the
"mailmap" in the "struct rev_info".
The log family of functions now calls the clear_mailmap() function
added in fa8afd18e5a (revisions API: provide and use a
release_revisions(), 2021-09-19), allowing us to whitelist some tests
with "TEST_PASSES_SANITIZE_LEAK=true".
Unfortunately having a pointer to a mailmap in "struct rev_info"
instead of an embedded member that we "own" get a bit messy, as can be
seen in the change to builtin/commit.c.
When we free() this data we won't be able to tell apart a pointer to a
"mailmap" on the heap from one on the stack. As seen in
ea57bc0d41 (log: add --use-mailmap option, 2013-01-05) the "log"
family allocates it on the heap, but in the find_author_by_nickname()
code added in ea16794e43 (commit: search author pattern against
mailmap, 2013-08-23) we allocated it on the stack instead.
Ideally we'd simply change that member to a "struct string_list
mailmap" and never free() the "mailmap" itself, but that would be a
much larger change to the revisions API.
We have code that needs to hand an existing "mailmap" to a "struct
rev_info", while we could change all of that, let's not go there
now.
The complexity isn't in the ownership of the "mailmap" per-se, but
that various things assume a "rev_info.mailmap == NULL" means "doesn't
want mailmap", if we changed that to an init'd "struct string_list
we'd need to carefully refactor things to change those assumptions.
Let's instead always free() it, and simply declare that if you add
such a "mailmap" it must be allocated on the heap. Any modern libc
will correctly panic if we free() a stack variable, so this should be
safe going forward.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Extend the the release_revisions() function so that it frees the
"commits" in the "struct rev_info".
We don't expect to use this "struct rev_info" again, so there's no
reason to NULL out revs->commits, as e.g. simplify_merges() and
create_boundary_commit_list() do.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use release_revisions() for users of "struct rev_list" that reach into
the "struct rev_info" and clear the "prune_data" already.
In a subsequent commit we'll teach release_revisions() to clear this
itself, but in the meantime let's invoke release_revisions() here to
clear anything else we may have missed, and for reasons of having
consistent boilerplate.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use a release_revisions() with those "struct rev_list" users which
already "UNLEAK" the struct. It may seem odd to simultaneously attempt
to free() memory, but also to explicitly ignore whether we have memory
leaks in the same.
As explained in preceding commits this is being done to use the
built-in commands as a guinea pig for whether the release_revisions()
function works as expected, we'd like to test e.g. whether we segfault
as we change it. In subsequent commits we'll then remove these
UNLEAK() as the function is made to free the memory that caused us to
add them in the first place.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In preparation for having the "log" family of functions make wider use
of release_revisions() let's have them call it just before
exiting. This changes the "log", "whatchanged", "show",
"format-patch", etc. commands, all of which live in this file.
The release_revisions() API still only frees the "pending" member, but
will learn to release more members of "struct rev_info" in subsequent
commits.
In the case of "format-patch" revert the addition of UNLEAK() in
dee839a263 (format-patch: mark rev_info with UNLEAK, 2021-12-16),
which will cause several tests that previously passed under
"TEST_PASSES_SANITIZE_LEAK=true" to start failing.
In subsequent commits we'll now be able to use those tests to check
whether that part of the API is really leaking memory, and will fix
all of those memory leaks. Removing the UNLEAK() allows us to make
incremental progress in that direction. See [1] for further details
about this approach.
Note that the release_revisions() will not be sufficient to deal with
the code in cmd_show() added in 5d7eeee2ac (git-show: grok blobs,
trees and tags, too, 2006-12-14) which clobbers the "pending" array in
the case of "OBJ_COMMIT". That will need to be dealt with by some
future follow-up work.
1. https://lore.kernel.org/git/220218.861r00ib86.gmgdl@evledraar.gmail.com/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the case of cmd_main() in http-push.c we need to move the
deceleration of the "struct rev-list" into the loop over the
"remote_refs" when adding a release_revisions().
We'd previously set up the "revs" for each remote, but would
potentially leak memory on each one.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a release_revisions() to various users of "struct rev_info" which
requires a minor refactoring to a "goto cleanup" pattern to use that
function.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the initialization of the "revision" member of "struct
stash_info" to be initialized vi a macro, and more importantly that
that initializing function be tasked to free it, usually via a "goto
cleanup" pattern.
Despite the "revision" name (and the topic of the series containing
this commit) the "stash info" has nothing to do with the "struct
rev_info". I'm making this change because in the subsequent commit
when we do want to free the "struct rev_info" via a "goto cleanup"
pattern we'd otherwise free() uninitialized memory in some cases, as
we only strbuf_init() the string in get_stash_info().
So while it's not the smallest possible change, let's convert all
users of this pattern in the file while we're at it.
A good follow-up to this change would be to change all the "ret = -1;
goto done;" in this file to instead use a "goto cleanup", and
initialize "int ret = -1" at the start of the relevant functions. That
would allow us to drop a lot of needless brace verbosity on two-line
"if" statements, but let's leave that alone for now.
To ensure that there's a 1=1 mapping between owners of the "struct
stash_info" and free_stash_info() change the assert_stash_ref()
function to be a trivial get_stash_info_assert() wrapper. The caller
will call free_stash_info(), and by returning -1 we'll eventually (via
!!ret) exit with status 1 anyway.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use release_revisions() to various users of "struct rev_list" which
need to have their "struct rev_info" zero-initialized before we can
start using it.
For the bundle.c code see the early exit case added in
3bbbe467f2 (bundle verify: error out if called without an object
database, 2019-05-27).
For the relevant bisect.c code see 45b6370812 (bisect: libify
`check_good_are_ancestors_of_bad` and its dependents, 2020-02-17).
For the submodule.c code see the "goto" on "(!left || !right || !sub)"
added in 8e6df65015 (submodule: refactor show_submodule_summary with
helper function, 2016-08-31).
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
