The meson-build procedure is integrated into CI to catch and
prevent bitrotting.
* ps/ci-meson:
ci: wire up Meson builds
t: introduce compatibility options to clar-based tests
t: fix out-of-tree tests for some git-p4 tests
Makefile: detect missing Meson tests
meson: detect missing tests at configure time
t/unit-tests: rename clar-based unit tests to have a common prefix
Makefile: drop -DSUPPRESS_ANNOTATED_LEAKS
ci/lib: support custom output directories when creating test artifacts
Start working to make the codebase buildable with -Wsign-compare.
* ps/build-sign-compare:
t/helper: don't depend on implicit wraparound
scalar: address -Wsign-compare warnings
builtin/patch-id: fix type of `get_one_patchid()`
builtin/blame: fix type of `length` variable when emitting object ID
gpg-interface: address -Wsign-comparison warnings
daemon: fix type of `max_connections`
daemon: fix loops that have mismatching integer types
global: trivial conversions to fix `-Wsign-compare` warnings
pkt-line: fix -Wsign-compare warning on 32 bit platform
csum-file: fix -Wsign-compare warning on 32-bit platform
diff.h: fix index used to loop through unsigned integer
config.mak.dev: drop `-Wno-sign-compare`
global: mark code units that generate warnings with `-Wsign-compare`
compat/win32: fix -Wsign-compare warning in "wWinMain()"
compat/regex: explicitly ignore "-Wsign-compare" warnings
git-compat-util: introduce macros to disable "-Wsign-compare" warnings
Reftable backend adds check for upper limit of log's update_index.
* kn/reftable-writer-log-write-verify:
reftable/writer: ensure valid range for log's update_index
Our unit tests that don't yet use the clar unit testing framework ignore
any option that they do not understand. It is thus fine to just pass
test options we set up globally to those unit tests as they are simply
ignored. This makes our life easier because we don't have to special
case those options with Meson, where test options are set up globally
via `meson test --test-args=`.
But our clar-based unit testing framework is way stricter here and will
fail in case it is passed an unknown option. Stub out these options with
no-ops to make our life a bit easier.
Note that this also requires us to remove the `-x` short option for
`--exclude`. This is because `-x` has another meaning in our integration
tests, as it enables shell tracing. I doubt there are a lot of people
out there using it as we only got a small hand full of clar tests in the
first place. So better change it now so that we can in the long run
improve compatibility between the two different test drivers.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
All of the code files for unit tests using the self-grown unit testing
framework have a "t-" prefix to their name. This makes it easy to
identify them and use globbing in our Makefile and in other places. On
the other hand though, our clar-based unit tests have no prefix at all
and thus cannot easily be discerned from other files in the unit test
directory.
Introduce a new "u-" prefix for clar-based unit tests. This prefix will
be used in a subsequent commit to easily identify such tests.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Optimize reading random references out of the reftable backend by
allowing reuse of iterator objects.
* ps/reftable-iterator-reuse:
refs/reftable: reuse iterators when reading refs
reftable/merged: drain priority queue on reseek
reftable/stack: add mechanism to notify callers on reload
refs/reftable: refactor reflog expiry to use reftable backend
refs/reftable: refactor reading symbolic refs to use reftable backend
refs/reftable: read references via `struct reftable_backend`
refs/reftable: figure out hash via `reftable_stack`
reftable/stack: add accessor for the hash ID
refs/reftable: handle reloading stacks in the reftable backend
refs/reftable: encapsulate reftable stack
Isolates the reftable subsystem from the rest of Git's codebase by
using fewer pieces of Git's infrastructure.
* ps/reftable-detach:
reftable/system: provide thin wrapper for lockfile subsystem
reftable/stack: drop only use of `get_locked_file_path()`
reftable/system: provide thin wrapper for tempfile subsystem
reftable/stack: stop using `fsync_component()` directly
reftable/system: stop depending on "hash.h"
reftable: explicitly handle hash format IDs
reftable/system: move "dir.h" to its only user
We use a singleton empty array to initialize a `struct strvec`;
similar to the empty string singleton we use to initialize a `struct
strbuf`.
Note that an empty strvec instance (with zero elements) does not
necessarily need to be an instance initialized with the singleton.
Let's refer to strvec instances initialized with the singleton as
"empty-singleton" instances.
As a side note, this is the current `strvec_pop()`:
void strvec_pop(struct strvec *array)
{
if (!array->nr)
return;
free((char *)array->v[array->nr - 1]);
array->v[array->nr - 1] = NULL;
array->nr--;
}
So, with `strvec_pop()` an instance can become empty but it does
not going to be the an "empty-singleton".
This "empty-singleton" circumstance requires us to be careful when
adding elements to instances. Specifically, when adding the first
element: when we detach the strvec instance from the singleton and
set the internal pointer in the instance to NULL. After this point we
apply `realloc()` on the pointer. We do this in
`strvec_push_nodup()`, for example.
The recently introduced `strvec_splice()` API is expected to be
normally used with non-empty strvec's. However, it can also end up
being used with "empty-singleton" strvec's:
struct strvec arr = STRVEC_INIT;
int a = 0, b = 0;
... no modification to arr, a or b ...
const char *rep[] = { "foo" };
strvec_splice(&arr, a, b, rep, ARRAY_SIZE(rep));
So, we'll try to add elements to an "empty-singleton" strvec instance.
Avoid misapplying `realloc()` to the singleton in `strvec_splice()` by
adding a special case for strvec's initialized with the singleton.
Signed-off-by: Rubén Justo <rjusto@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Each reftable addition has an associated update_index. While writing
refs, the update_index is verified to be within the range of the
reftable writer, i.e. `writer.min_update_index <= ref.update_index` and
`writer.max_update_index => ref.update_index`.
The corresponding check for reflogs in `reftable_writer_add_log` is
however missing. Add a similar check, but only check for the upper
limit. This is because reflogs are treated a bit differently than refs.
Each reflog entry in reftable has an associated update_index and we also
allow expiring entries in the middle, which is done by simply writing a
new reflog entry with the same update_index. This means, writing reflog
entries with update_index lesser than the writer's update_index is an
expected scenario.
Add a new unit test to check for the limits and fix some of the existing
tests, which were setting arbitrary values for the update_index by
ensuring they stay within the now checked limits.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
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>
Leakfixes.
* ps/leakfixes-part-10: (27 commits)
t: remove TEST_PASSES_SANITIZE_LEAK annotations
test-lib: unconditionally enable leak checking
t: remove unneeded !SANITIZE_LEAK prerequisites
t: mark some tests as leak free
t5601: work around leak sanitizer issue
git-compat-util: drop now-unused `UNLEAK()` macro
global: drop `UNLEAK()` annotation
t/helper: fix leaking commit graph in "read-graph" subcommand
builtin/branch: fix leaking sorting options
builtin/init-db: fix leaking directory paths
builtin/help: fix leaks in `check_git_cmd()`
help: fix leaking return value from `help_unknown_cmd()`
help: fix leaking `struct cmdnames`
help: refactor to not use globals for reading config
builtin/sparse-checkout: fix leaking sanitized patterns
split-index: fix memory leak in `move_cache_to_base_index()`
git: refactor builtin handling to use a `struct strvec`
git: refactor alias handling to use a `struct strvec`
strvec: introduce new `strvec_splice()` function
line-log: fix leak when rewriting commit parents
...
In 5bf96e0c39 (reftable/generic: move seeking of records into the
iterator, 2024-05-13) we have refactored the reftable codebase such that
iterators can be initialized once and then re-seeked multiple times.
This feature is used by 1869525066 (refs/reftable: wire up support for
exclude patterns, 2024-09-16) in order to skip records based on exclude
patterns provided by the caller.
The logic to re-seek the merged iterator is insufficient though because
we don't drain the priority queue on a re-seek. This means that the
queue may contain stale entries and thus reading the next record in the
queue will return the wrong entry. While this is an obvious bug, it is
harmless in the context of above exclude patterns:
- If the queue contained stale entries that match the pattern then the
caller would already know to filter out such refs. This is because
our codebase is prepared to handle backends that don't have a way to
efficiently implement exclude patterns.
- If the queue contained stale entries that don't match the pattern
we'd eventually filter out any duplicates. This is because the
reftable code discards items with the same ref name and sorts any
remaining entries properly.
So things happen to work in this context regardless of the bug, and
there is no other use case yet where we re-seek iterators. We're about
to introduce a caching mechanism though where iterators are reused by
the reftable backend, and that will expose the bug.
Fix the issue by draining the priority queue when seeking and add a
testcase that surfaces the issue.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new `strvec_splice()` function that can replace a range of
strings in the vector with another array of strings. This function will
be used in subsequent commits.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* ps/reftable-detach:
reftable/system: provide thin wrapper for lockfile subsystem
reftable/stack: drop only use of `get_locked_file_path()`
reftable/system: provide thin wrapper for tempfile subsystem
reftable/stack: stop using `fsync_component()` directly
reftable/system: stop depending on "hash.h"
reftable: explicitly handle hash format IDs
reftable/system: move "dir.h" to its only user
We use the lockfile subsystem to write lockfiles for "tables.list". As
with the tempfile subsystem, the lockfile subsystem also hooks into our
infrastructure to prune stale locks via atexit(3p) or signal handlers.
Furthermore, the lockfile subsystem also handles locking timeouts, which
do add quite a bit of logic. Having to reimplement that in the context
of Git wouldn't make a whole lot of sense, and it is quite likely that
downstream users of the reftable library may have a better idea for how
exactly to implement timeouts.
So again, provide a thin wrapper for the lockfile subsystem instead such
that the compatibility shim is fully self-contained.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We include "hash.h" in "reftable/system.h" such that we can use hash
format IDs as well as the raw size of SHA1 and SHA256. As we are in the
process of converting the reftable library to become standalone we of
course cannot rely on those constants anymore.
Introduce a new `enum reftable_hash` to replace internal uses of the
hash format IDs and new constants that replace internal uses of the hash
size. Adapt the reftable backend to set up the correct hash function.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We still include "dir.h" in "reftable/system.h" even though it is not
used by anything but by a single unit test. Move it over into that unit
test so that we don't accidentally use any functionality provided by it
in the reftable codebase.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert "clar-generate.awk" into a shell script that invokes awk(1).
This allows us to avoid the shell redirect in the build system, which
may otherwise be a problem with build systems on platforms that use a
different shell.
While at it, wrap the overly long lines in the CMake build instructions.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Buildfix and upgrade of Clar to a newer version.
* ps/upgrade-clar:
cmake: set up proper dependencies for generated clar headers
cmake: fix compilation of clar-based unit tests
Makefile: extract script to generate clar declarations
Makefile: adjust sed command for generating "clar-decls.h"
t/unit-tests: update clar to 206accb
Implements a new reftable-specific strbuf replacement to reduce
reftable's dependency on Git-specific data structures.
* ps/reftable-strbuf:
reftable: handle trivial `reftable_buf` errors
reftable/stack: adapt `stack_filename()` to handle allocation failures
reftable/record: adapt `reftable_record_key()` to handle allocation failures
reftable/stack: adapt `format_name()` to handle allocation failures
t/unit-tests: check for `reftable_buf` allocation errors
reftable/blocksource: adapt interface name
reftable: convert from `strbuf` to `reftable_buf`
reftable/basics: provide new `reftable_buf` interface
reftable: stop using `strbuf_addf()`
reftable: stop using `strbuf_addbuf()`
Extract the script to generate function declarations for the clar unit
testing framework into a standalone script. This is done such that we
can reuse it in other build systems.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Update clar from:
- 1516124 (Merge pull request #97 from pks-t/pks-whitespace-fixes, 2024-08-15).
To:
- 206accb (Merge pull request #108 from pks-t/pks-uclibc-without-wchar, 2024-10-21)
This update includes a bunch of fixes and improvements that we have
discussed in Git when initial support for clar was merged:
- There is a ".editorconfig" file now.
- Compatibility with Windows has been improved so that the clar
compiles on this platform without an issue. This has been tested
with Cygwin, MinGW and Microsoft Visual Studio.
- clar now uses CMake. This does not impact us at all as we wire up
the clar into our own build infrastructure anyway. This conversion
was done such that we can easily run CI jobs against Windows.
- Allocation failures are now checked for consistently.
- We now define feature test macros in "clar.c", which fixes
compilation on some platforms that didn't previously pull in
non-standard functions like lstat(3p) or strdup(3p). This was
reported by a user of OpenSUSE Leap.
- We stop using `struct timezone`, which is undefined behaviour
nowadays and results in a compilation error on some platforms.
- We now use the combination of mktemp(3) and mkdir(3) on SunOS, same
as we do on NonStop.
- We now support uClibc without support for <wchar.h>.
The most important bits here are the improved platform compatibility
with Windows, OpenSUSE, SunOS and uClibc.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Adapt the name of the `strbuf` block source to no longer relate to this
interface, but instead to the `reftable_buf` interface.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Convert the reftable library to use the `reftable_buf` interface instead
of the `strbuf` interface. This is mostly a mechanical change via sed(1)
with some manual fixes where functions for `strbuf` and `reftable_buf`
differ. The converted code does not yet handle allocation failures. This
will be handled in subsequent commits.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
We're about to introduce our own `reftable_buf` type to replace
`strbuf`. One function we'll have to convert is `strbuf_addf()`, which
is used in a handful of places. This function uses `snprintf()`
internally, which makes porting it a bit more involved:
- It is not available on all platforms.
- Some platforms like Windows have broken implementations.
So by using `snprintf()` we'd also push the burden on downstream users
of the reftable library to make available a properly working version of
it.
Most callsites of `strbuf_addf()` are trivial to convert to not using
it. We do end up using `snprintf()` in our unit tests, but that isn't
much of a problem for downstream users of the reftable library.
While at it, remove a useless call to `strbuf_reset()` in
`t_reftable_stack_auto_compaction_with_locked_tables()`. We don't write
to the buffer before this and initialize it with `STRBUF_INIT`, so there
is no need to reset anything.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
The reftable library is now prepared to expect that the memory
allocation function given to it may fail to allocate and to deal
with such an error.
* ps/reftable-alloc-failures: (26 commits)
reftable/basics: fix segfault when growing `names` array fails
reftable/basics: ban standard allocator functions
reftable: introduce `REFTABLE_FREE_AND_NULL()`
reftable: fix calls to free(3P)
reftable: handle trivial allocation failures
reftable/tree: handle allocation failures
reftable/pq: handle allocation failures when adding entries
reftable/block: handle allocation failures
reftable/blocksource: handle allocation failures
reftable/iter: handle allocation failures when creating indexed table iter
reftable/stack: handle allocation failures in auto compaction
reftable/stack: handle allocation failures in `stack_compact_range()`
reftable/stack: handle allocation failures in `reftable_new_stack()`
reftable/stack: handle allocation failures on reload
reftable/reader: handle allocation failures in `reader_init_iter()`
reftable/reader: handle allocation failures for unindexed reader
reftable/merged: handle allocation failures in `merged_table_init_iter()`
reftable/writer: handle allocation failures in `reftable_new_writer()`
reftable/writer: handle allocation failures in `writer_index_hash()`
reftable/record: handle allocation failures when decoding records
...
We have several calls to `FREE_AND_NULL()` in the reftable library,
which of course uses free(3P). As the reftable allocators are pluggable
we should rather call the reftable specific function, which is
`reftable_free()`.
Introduce a new macro `REFTABLE_FREE_AND_NULL()` and adapt the callsites
accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a small set of calls to free(3P) in the reftable library. As
the reftable allocators are pluggable we should rather call the reftable
specific function, which is `reftable_free()`.
Convert the code accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Handle trivial allocation failures in the reftable library and its unit
tests.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The tree interfaces of the reftable library handle both insertion and
searching of tree nodes with a single function, where the behaviour is
altered between the two via an `insert` bit. This makes it quit awkward
to handle allocation failures because on inserting we'd have to check
for `NULL` pointers and return an error, whereas on searching entries we
don't have to handle it as an allocation error.
Split up concerns of this function into two separate functions, one for
inserting entries and one for searching entries. This makes it easy for
us to check for allocation errors as `tree_insert()` should never return
a `NULL` pointer now. Adapt callers accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Handle allocation failures in `block_writer_init()` and
`block_reader_init()`. This requires us to bubble up error codes into
`writer_reinit_block_writer()`. Adapt call sites accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Handle allocation failures in `reader_init_iter()`. This requires us to
also adapt `reftable_reader_init_*_iterator()` to bubble up the new
error codes. Adapt callers accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Handle allocation failures in `merged_table_init_iter()`. While at it,
merge `merged_iter_init()` into the function. It only has a single
caller and merging them makes it easier to handle allocation failures
consistently.
This change also requires us to adapt `reftable_stack_init_*_iterator()`
to bubble up the new error codes of `merged_table_iter_init()`. Adapt
callsites accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Handle allocation failures in `reftable_new_writer()`. Adapt the
function to return an error code to return such failures. While at it,
rename it to match our code style as we have to touch up every callsite
anyway.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Handle allocation failures in `parse_names()` by returning `NULL` in
case any allocation fails. While at it, refactor the function to return
the array directly instead of assigning it to an out-pointer.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Give timeout to the locking code to write to reftable.
* ps/reftable-concurrent-writes:
refs/reftable: reload locked stack when preparing transaction
reftable/stack: allow locking of outdated stacks
refs/reftable: introduce "reftable.lockTimeout"
The reftable backend learned to more efficiently handle exclude
patterns while enumerating the refs.
* ps/reftable-exclude:
refs/reftable: wire up support for exclude patterns
reftable/reader: make table iterator reseekable
t/unit-tests: introduce reftable library
Makefile: stop listing test library objects twice
builtin/receive-pack: fix exclude patterns when announcing refs
refs: properly apply exclude patterns to namespaced refs
In `reftable_stack_new_addition()` we first lock the stack and then
check whether it is still up-to-date. If it is not we return an error to
the caller indicating that the stack is outdated.
This is overly restrictive in our ref transaction interface though: we
lock the stack right before we start to verify the transaction, so we do
not really care whether it is outdated or not. What we really want is
that the stack is up-to-date after it has been locked so that we can
verify queued updates against its current state while we know that it is
locked for concurrent modification.
Introduce a new flag `REFTABLE_STACK_NEW_ADDITION_RELOAD` that alters
the behaviour of `reftable_stack_init_addition()` in this case: when we
notice that it is out-of-date we reload it instead of returning an error
to the caller.
This logic will be wired up in the reftable backend in the next commit.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Import clar unit tests framework libgit2 folks invented for our
use.
* ps/clar-unit-test:
Makefile: rename clar-related variables to avoid confusion
clar: add CMake support
t/unit-tests: convert ctype tests to use clar
t/unit-tests: convert strvec tests to use clar
t/unit-tests: implement test driver
Makefile: wire up the clar unit testing framework
Makefile: do not use sparse on third-party sources
Makefile: make hdr-check depend on generated headers
Makefile: fix sparse dependency on GENERATED_H
clar: stop including `shellapi.h` unnecessarily
clar(win32): avoid compile error due to unused `fs_copy()`
clar: avoid compile error with mingw-w64
t/clar: fix compatibility with NonStop
t: import the clar unit testing framework
t: do not pass GIT_TEST_OPTS to unit tests with prove
Another reftable test migrated to the unit-test framework.
* cp/unit-test-reftable-stack:
t-reftable-stack: add test for stack iterators
t-reftable-stack: add test for non-default compaction factor
t-reftable-stack: use reftable_ref_record_equal() to compare ref records
t-reftable-stack: use Git's tempfile API instead of mkstemp()
t: harmonize t-reftable-stack.c with coding guidelines
t: move reftable/stack_test.c to the unit testing framework
* cp/unit-test-reftable-stack:
t-reftable-stack: add test for stack iterators
t-reftable-stack: add test for non-default compaction factor
t-reftable-stack: use reftable_ref_record_equal() to compare ref records
t-reftable-stack: use Git's tempfile API instead of mkstemp()
t: harmonize t-reftable-stack.c with coding guidelines
t: move reftable/stack_test.c to the unit testing framework
In 67ce50ba26 (Merge branch 'ps/reftable-reusable-iterator', 2024-05-30)
we have refactored the interface of reftable iterators such that they
can be reused in theory. This patch series only landed the required
changes on the interface level, but didn't yet implement the actual
logic to make iterators reusable.
As it turns out almost all of the infrastructure already does support
re-seeking. The only exception is the table iterator, which does not
reset its `is_finished` bit. Do so and add a couple of tests that verify
that we can re-seek iterators.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have recently migrated all of the reftable unit tests that were part
of the reftable library into our own unit testing framework. As part of
that migration we have duplicated some of the functionality that was
part of the reftable test framework into each of the migrated test
suites. This was a sensible decision to not have all of the migrations
dependent on each other, but now that the migration is done it makes
sense to deduplicate the functionality again.
Introduce a new reftable test library that hosts some shared code and
adapt tests to use it.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>