The functions `repo_get_merge_bases_many()` and friends accepts an array
of commits as well as a parameter that indicates how large that array
is. This parameter is using a signed integer, which leads to a couple of
warnings with -Wsign-compare.
Refactor the code to use `size_t` to track indices instead and adapt
callers accordingly. While most callers are trivial, there are two
callers that require a bit more scrutiny:
- builtin/merge-base.c:show_merge_base() subtracts `1` from the
`rev_nr` before calling `repo_get_merge_bases_many_dirty()`, so if
the variable was `0` it would wrap. This code is fine though because
its only caller will execute that code only when `argc >= 2`, and it
follows that `rev_nr >= 2`, as well.
- bisect.ccheck_merge_bases() similarly subtracts `1` from `rev_nr`.
Again, there is only a single caller that populates `rev_nr` with
`good_revs.nr`. And because a bisection always requires at least one
good revision it follws that `rev_nr >= 1`.
Mark the file as -Wsign-compare-clean.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have a bunch of loops which iterate up to an unsigned boundary using
a signed index, which generates warnigs because we compare a signed and
unsigned value in the loop condition. Address these sites for trivial
cases and enable `-Wsign-compare` warnings for these code units.
This patch only adapts those code units where we can drop the
`DISABLE_SIGN_COMPARE_WARNINGS` macro in the same step.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Mark code units that generate warnings with `-Wsign-compare`. This
allows for a structured approach to get rid of all such warnings over
time in a way that can be easily measured.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "reach" test tool doesn't bother to clean up any of its allocated
resources, causing various leaks. Plug them.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our error reporting routines append a trailing newline, and the strings
we pass to them should not include them (otherwise we get an extra blank
line after the message).
These cases were all found by looking at the results of:
git grep -P '[^_](error|error_errno|warning|die|die_errno)\(.*\\n"[,)]' '*.c'
Note that we _do_ sometimes include a newline in the middle of such
messages, to create multiline output (hence our grep matching "," or ")"
after we see the newline, so we know we're at the end of the string).
It's possible that one or more of these cases could intentionally be
including a blank line at the end, but having looked at them all
manually, I think these are all just mistakes.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a new reachability algorithm that intends to discover (from a heuristic)
which branch was used as the starting point for a given commit. Add focused
tests using the 'test-tool reach' command.
In repositories that use pull requests (or merge requests) to advance one or
more "protected" branches, the history of that reference can be recovered by
following the first-parent history in most cases. Most are completed using
no-fast-forward merges, though squash merges are quite common. Less common
is rebase-and-merge, which still validates this assumption. Finally, the
case that breaks this assumption is the fast-forward update (with potential
rebasing). Even in this case, the previous commit commonly appears in the
first-parent history of the branch.
Similar assumptions can be made for a topic branch created by a single user
with the intention to merge back into another branch. Using 'git commit',
'git merge', and 'git cherry-pick' from HEAD will default to having the
first-parent commit be the previous commit at HEAD. This history changes
only with commands such as 'git reset' or 'git rebase', where the command
names also imply that the branch is starting from a new location.
With this movement of branches in mind, the following heuristic is proposed
as a way to determine the base branch for a given source branch:
Among a list of candidate base branches, select the candidate that
minimizes the number of commits in the first-parent history of the source
that are not in the first-parent history of the candidate.
Prior third-party solutions to this problem have used this optimization
criteria, but have relied upon extracting the first-parent history and
comparing those lists as tables instead of using commit-graph walks.
Given current command-line interface options, this optimization criteria is
not easy to detect directly. Even using the command
git rev-list --count --first-parent <base>..<source>
does not measure this count, as it uses full reachability from <base> to
determine which commits to remove from the range '<base>..<source>'. This
may lead to one asking if we should instead be using the full reachability
of the candidate and only the first-parent history of the source. This,
unfortunately, does not work for repositories that use long-lived branches
and automation to merge across those branches.
In extremely large repositories, merging into a single trunk may not be
feasible. This is usually due to the desired frequency of updates
(thousands of engineers doing daily work) combined with the time required to
perform a validation build. These factors combine to create significant
risk of semantic merge conflicts, leading to build breaks on the trunk. In
response, repository maintainers can create a single Level Zero (L0) trunk
and multiple Level One (L1) branches. By partitioning the engineers by
organization, these engineers may see lower risk of semantic merge conflicts
as well as be protected against build breaks in other L1 branches. The key
to making this system work is a semi-automated process of merging L1
branches into the L0 trunk and vice-versa. In a large enough organization,
these L1 branches may further split into L2 or L3 branches, but the same
principles apply for merging across deeper levels.
If these automated merges use a typical merge with the second parent
bringing in the "new" content, then each L0 and L1 branch can track its
previous positions by following first-parent history, which appear as
parallel paths (until reaching the first place where the branches diverged).
If we also walk to second parents, then the histories overlap significantly
and cannot be distinguished except for very-recent changes.
For this reason, the first-parent condition should be symmetrical across the
base and source branches.
Another common case for desiring the result of this optimization method is
the use of release branches. When releasing a version of a repository, a
branch can be used to track that release. Any updates that are worth fixing
in that release can be merged to the release branch and shipped with only
the necessary fixes without any new features introduced in the trunk branch.
The 'maint-2.<X>' branches represent this pattern in the Git project. The
microsoft/git fork uses 'vfs-2.<X>.<Y>' branches to track the changes that
are custom to that fork on top of each upstream Git release 2.<X>.<Y>. This
application doesn't need the symmetrical first-parent condition, but the use
of first-parent histories does not change the results for these branches.
To determine the base branch from a list of candidates, create a new method
in commit-reach.c that performs a single* commit-graph walk. The core
concept is to walk first-parents starting at the candidate bases and the
source, tracking the "best" base to reach a given commit. Use generation
numbers to ensure that a commit is walked at most once and all children have
been explored before visiting it. When reaching a commit that is reachable
from both a base and the source, we will then have a guarantee that this is
the closest intersection of first-parent histories. Track the best base to
reach that commit and return it as a result. In rare cases involving
multiple root commits, the first-parent history of the source may never
intersect any of the candidates and thus a null result is returned.
* There are up to two walks, since we require all commits to have a computed
generation number in order to avoid incorrect results. This is similar to
the need for computed generation numbers in ahead_behind() as implemented
in fd67d149bd (commit-reach: implement ahead_behind() logic, 2023-03-20).
In order to track the "best" base, use a new commit slab that stores an
integer. This value defaults to zero upon initialization, so use -1 to
track that the source commit can reach this commit and use 'i + 1' to track
that the ith base can reach this commit. When multiple bases can reach a
commit, minimize the index to break ties. This allows the caller to specify
an order to the bases that determines some amount of preference when the
heuristic does not result in a unique result.
The trickiest part of the integer slab is what happens when reaching a
collision among the histories of the bases and the history of the source.
This is noticed when viewing the first parent and seeing that it has a slab
value that differs in sign (negative or positive). In this case, the
collision commit is stored in the method variable 'branch_point' and its
slab value is set to -1. The index of the best base (so far) is stored in
the method variable 'best_index'. It is possible that there are multiple
commits that have the branch_point as its first parent, leading to multiple
updates of best_index. The result is determined when 'branch_point' is
visited in the commit walk, giving the guarantee that all commits that could
reach 'branch_point' were visited.
Several interesting cases of collisions and different results are tested in
the t6600-test-reach.sh script. Recall that this script also tests the
algorithm in three possible states involving the commit-graph file and how
many commits are written in the file. This provides some coverage of the
need (and lack of need) for the ensure_generations_valid() method.
Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use of the `the_repository` variable is deprecated nowadays, and we
slowly but steadily convert the codebase to not use it anymore. Instead,
callers should be passing down the repository to work on via parameters.
It is hard though to prove that a given code unit does not use this
variable anymore. The most trivial case, merely demonstrating that there
is no direct use of `the_repository`, is already a bit of a pain during
code reviews as the reviewer needs to manually verify claims made by the
patch author. The bigger problem though is that we have many interfaces
that implicitly rely on `the_repository`.
Introduce a new `USE_THE_REPOSITORY_VARIABLE` macro that allows code
units to opt into usage of `the_repository`. The intent of this macro is
to demonstrate that a certain code unit does not use this variable
anymore, and to keep it from new dependencies on it in future changes,
be it explicit or implicit
For now, the macro only guards `the_repository` itself as well as
`the_hash_algo`. There are many more known interfaces where we have an
implicit dependency on `the_repository`, but those are not guarded at
the current point in time. Over time though, we should start to add
guards as required (or even better, just remove them).
Define the macro as required in our code units. As expected, most of our
code still relies on the global variable. Nearly all of our builtins
rely on the variable as there is no way yet to pass `the_repository` to
their entry point. For now, declare the macro in "biultin.h" to keep the
required changes at least a little bit more contained.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Both `peel_object()` and `peel_iterated_oid()` implicitly rely on
`the_repository` to look up objects. Despite the fact that we want to
get rid of `the_repository`, it also leads to some restrictions in our
ref iterators when trying to retrieve the peeled value for a repository
other than `the_repository`.
Refactor these functions such that both take a repository as argument
and remove the now-unnecessary restrictions.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `merge_bases_many()` function was just taught to indicate parsing
errors, and now the `repo_get_merge_bases_many()` function is aware of
that, too.
Naturally, there are a lot of callers that need to be adjusted now, too.
Next stop: `repo_get_merge_bases_dirty()`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently this function treats unrelated commit histories the same way
as commit histories with missing commit objects.
Typically, missing commit objects constitute a corrupt repository,
though, and should be reported as such. The next commits will make it
so, but there is one exception: In `git fetch --update-shallow` we
_expect_ commit objects to be missing, and we do want to treat the
now-incomplete commit histories as unrelated.
To allow for that, let's introduce an additional parameter that is
passed to `repo_in_merge_bases_many()` to trigger this behavior, and use
it in the two callers in `shallow.c`.
This commit changes behavior slightly: unless called from the
`shallow.c` functions that set the `ignore_missing_commits` bit, any
non-existing tip commit that is passed to `repo_in_merge_bases_many()`
will now result in an error.
Note: When encountering missing commits while traversing the commit
history in search for merge bases, with this commit there won't be a
change in behavior just yet, their children will still be interpreted as
root commits. This bug will get fixed by follow-up commits.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Each of these were checked with
gcc -E -I. ${SOURCE_FILE} | grep ${HEADER_FILE}
to ensure that removing the direct inclusion of the header actually
resulted in that header no longer being included at all (i.e. that
no other header pulled it in transitively).
...except for a few cases where we verified that although the header
was brought in transitively, nothing from it was directly used in
that source file. These cases were:
* builtin/credential-cache.c
* builtin/pull.c
* builtin/send-pack.c
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Enumerating refs in the packed-refs file, while excluding refs that
match certain patterns, has been optimized.
* tb/refs-exclusion-and-packed-refs:
ls-refs.c: avoid enumerating hidden refs where possible
upload-pack.c: avoid enumerating hidden refs where possible
builtin/receive-pack.c: avoid enumerating hidden references
refs.h: implement `hidden_refs_to_excludes()`
refs.h: let `for_each_namespaced_ref()` take excluded patterns
revision.h: store hidden refs in a `strvec`
refs/packed-backend.c: add trace2 counters for jump list
refs/packed-backend.c: implement jump lists to avoid excluded pattern(s)
refs/packed-backend.c: refactor `find_reference_location()`
refs: plumb `exclude_patterns` argument throughout
builtin/for-each-ref.c: add `--exclude` option
ref-filter.c: parameterize match functions over patterns
ref-filter: add `ref_filter_clear()`
ref-filter: clear reachable list pointers after freeing
ref-filter.h: provide `REF_FILTER_INIT`
refs.c: rename `ref_filter`
Provide a sane initialization value for `struct ref_filter`, which in a
subsequent patch will be used to initialize a new field.
In the meantime, ensure that the `ref_filter` struct used in the
test-helper's `cmd__reach()` is zero-initialized. The lack of
initialization is OK, since `commit_contains()` only looks at the single
`with_commit_tag_algo` field that *is* initialized directly above.
So this does not fix a bug, but rather prevents one from biting us in
the future.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
alloc_nr, ALLOC_GROW, and ALLOC_GROW_BY are commonly used macros for
dynamic array allocation. Moving these macros to git-compat-util.h with
the other alloc macros focuses alloc.[ch] to allocation for Git objects
and additionally allows us to remove inclusions to alloc.h from files
that solely used the above macros.
Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* ab/remove-implicit-use-of-the-repository:
libs: use "struct repository *" argument, not "the_repository"
post-cocci: adjust comments for recent repo_* migration
cocci: apply the "revision.h" part of "the_repository.pending"
cocci: apply the "rerere.h" part of "the_repository.pending"
cocci: apply the "refs.h" part of "the_repository.pending"
cocci: apply the "promisor-remote.h" part of "the_repository.pending"
cocci: apply the "packfile.h" part of "the_repository.pending"
cocci: apply the "pretty.h" part of "the_repository.pending"
cocci: apply the "object-store.h" part of "the_repository.pending"
cocci: apply the "diff.h" part of "the_repository.pending"
cocci: apply the "commit.h" part of "the_repository.pending"
cocci: apply the "commit-reach.h" part of "the_repository.pending"
cocci: apply the "cache.h" part of "the_repository.pending"
cocci: add missing "the_repository" macros to "pending"
cocci: sort "the_repository" rules by header
cocci: fix incorrect & verbose "the_repository" rules
cocci: remove dead rule from "the_repository.pending.cocci"
Apply the part of "the_repository.pending.cocci" pertaining to
"commit-reach.h".
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Apply the part of "the_repository.pending.cocci" pertaining to
"cache.h".
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Dozens of files made use of gettext functions, without explicitly
including gettext.h. This made it more difficult to find which files
could remove a dependence on cache.h. Make C files explicitly include
gettext.h if they are using it.
However, while compat/fsmonitor/fsm-ipc-darwin.c should also gain an
include of gettext.h, it was left out to avoid conflicting with an
in-flight topic.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Ever since a64215b6cd ("object.h: stop depending on cache.h; make
cache.h depend on object.h", 2023-02-24), we have a few headers that
could have replaced their include of cache.h with an include of
object.h. Make that change now.
Some C files had to start including cache.h after this change (or some
smaller header it had brought in), because the C files were depending
on things from cache.h but were only formerly implicitly getting
cache.h through one of these headers being modified in this patch.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This allows us to replace includes of cache.h with includes of the much
smaller alloc.h in many places. It does mean that we also need to add
includes of alloc.h in a number of C files.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change various cmd_* functions that claim to return an "int" to use
"return" instead of exit() to indicate an exit code. These were not
marked with NORETURN, and by directly exit()-ing we'll skip the
cleanup git.c would otherwise do (e.g. closing fd's, erroring if we
can't). See run_builtin() in git.c.
In the case of shell.c and sh-i18n--envsubst.c this was the result of
an incomplete migration to using a cmd_main() in 3f2e2297b9 (add an
extra level of indirection to main(), 2016-07-01).
This was spotted by SunCC 12.5 on Solaris 10 (gcc210 on the gccfarm).
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Way back in f9b8908b (commit.c: use generation numbers for
in_merge_bases(), 2018-05-01), a heuristic was used to short-circuit
the in_merge_bases() walk. This works just fine as long as the
caller is checking only two commits, but when there are multiple,
there is a possibility that this heuristic is _very wrong_.
Some code moves since then has changed this method to
repo_in_merge_bases_many() inside commit-reach.c. The heuristic
computes the minimum generation number of the "reference" list, then
compares this number to the generation number of the "commit".
In a recent topic, a test was added that used in_merge_bases_many()
to test if a commit was reachable from a number of commits pulled
from a reflog. However, this highlighted the problem: if any of the
reference commits have a smaller generation number than the given
commit, then the walk is skipped _even if there exist some with
higher generation number_.
This heuristic is wrong! It must check the MAXIMUM generation number
of the reference commits, not the MINIMUM.
This highlights a testing gap. t6600-test-reach.sh covers many
methods in commit-reach.c, including in_merge_bases() and
get_merge_bases_many(), but since these methods either restrict to
two input commits or actually look for the full list of merge bases,
they don't check this heuristic!
Add a possible input to "test-tool reach" that tests
in_merge_bases_many() and add tests to t6600-test-reach.sh that
cover this heuristic. This includes cases for the reference commits
having generation above and below the generation of the input commit,
but also having maximum generation below the generation of the input
commit.
The fix itself is to swap min_generation with a max_generation in
repo_in_merge_bases_many().
Reported-by: Srinidhi Kaushik <shrinidhi.kaushik@gmail.com>
Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
d91d6fbf26 (commit-reach: create repo_is_descendant_of(), 2020-06-17)
adds a repository aware version of is_descendant_of() and a backward
compatibility shim that is barely used.
Update all callers to directly use the new repo_is_descendant_of()
function instead; making the codebase simpler and pushing more
the_repository references higher up the stack.
Helped-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
14ba97f8 (alloc: allow arbitrary repositories for alloc functions,
2018-05-15) introduced parsed_object_pool->commit_count to keep count of
commits per repository and was used to assign commit->index.
However, commit-slab code requires commit->index values to be unique
and a global count would be correct, rather than a per-repo count.
Let's introduce a static counter variable, `parsed_commits_count` to
keep track of parsed commits so far.
As commit_count has no use anymore, let's also drop it from the struct.
Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The get_reachable_subset() method returns the list of commits in
the 'to' array that are reachable from at least one commit in the
'from' array. Add tests that check this method works in a few
cases:
1. All commits in the 'to' list are reachable. This exercises the
early-termination condition.
2. Some commits in the 'to' list are reachable. This exercises the
loop-termination condition.
3. No commits in the 'to' list are reachable. This exercises the
NULL return condition.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The can_all_from_reach_with_flag() algorithm was refactored in 4fbcca4e
"commit-reach: make can_all_from_reach... linear" but incorrectly
assumed that all objects provided were commits. During a fetch
negotiation, ok_to_give_up() in upload-pack.c may provide unpeeled tags
to the 'from' array. The current code creates a segfault.
Add a direct call to can_all_from_reach_with_flag() in 'test-tool reach'
and add a test in t6600-test-reach.sh that demonstrates this segfault.
Correct the issue by peeling tags when investigating the initial list
of objects in the 'from' array.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The commit_contains method has two modes which depend on the given
ref_filter struct. We have the "normal" algorithm (which is also the
typically-slow operation) and the "tag" algorithm. This difference is
essentially what changes performance for 'git branch --contains' versus
'git tag --contains'. There are thoughts that the data shapes used by
these two applications justify the different implementations.
Create tests using 'test-tool reach commit_contains [--tag]' to cover
both methods.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The can_all_from_reach_with_flags method is used by ok_to_give_up in
upload-pack.c to see if we have done enough negotiation during a fetch.
This method is intentionally created to preserve state between calls to
assist with stateful negotiation, such as over SSH.
To make this method testable, add a new can_all_from_reach method that
does the initial setup and final tear-down. We will later use this
method in production code. Call the method from 'test-tool reach' for
now.
Since this is a many-to-many reachability query, add a new type of input
to the 'test-tool reach' input format. Lines "Y:<committish>" create a
list of commits to be the reachability targets from the commits in the
'X' list. In the context of fetch negotiation, the 'X' commits are the
'want' commits and the 'Y' commits are the 'have' commits.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The get_merge_bases_many method returns a list of merge bases for a
single commit (A) against a list of commits (X). Some care is needed in
constructing the expected behavior because the result is not the
expected merge-base for an octopus merge with those parents but instead
the set of maximal commits that are reachable from A and at least one of
the commits in X.
Add get_merge_bases_many to 'test-tool reach' and create a test that
demonstrates that this output returns multiple results. Specifically, we
select a list of three commits such that we output two commits that are
reachable from one of the first two, respectively, and none are
reachable from the third.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The is_descendant_of method takes a single commit as its first parameter
and a list of commits as its second parameter. Extend the input of the
'test-tool reach' command to take multiple lines of the form
"X:<committish>" to construct a list of commits. Pass these to
is_descendant_of and create tests that check each result.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As we prepare to change the behavior of the algorithms in
commit-reach.c, create a new test-tool subcommand 'reach' to test these
methods on interesting commit-graph shapes.
To use the new test-tool, use 'test-tool reach <method>' and provide
input to stdin that describes the inputs to the method. Currently, we
only implement the ref_newer method, which requires two commits. Use
lines "A:<committish>" and "B:<committish>" for the two inputs. We will
expand this input later to accommodate methods that take lists of
commits.
The test t6600-test-reach.sh creates a repo whose commits form a
two-dimensional grid. This grid makes it easy for us to determine
reachability because commit-A-B can reach commit-X-Y if and only if A is
at least X and B is at least Y. This helps create interesting test cases
for each result of the methods in commit-reach.c.
We test all methods in three different states of the commit-graph file:
Non-existent (no generation numbers), fully computed, and mixed (some
commits have generation numbers and others do not).
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Patrick Steinhardt