Taylor Blau [Mon, 8 May 2023 17:38:12 +0000 (13:38 -0400)]
pack-bitmap.c: use commit boundary during bitmap traversal
When reachability bitmap coverage exists in a repository, Git will use a
different (and hopefully faster) traversal to compute revision walks.
Consider a set of positive and negative tips (which we'll refer to with
their standard bitmap parlance by "wants", and "haves"). In order to
figure out what objects exist between the tips, the existing traversal
in `prepare_bitmap_walk()` does something like:
1. Consider if we can even compute the set of objects with bitmaps,
and fall back to the usual traversal if we cannot. For example,
pathspec limiting traversals can't be computed using bitmaps (since
they don't know which objects are at which paths). The same is true
of certain kinds of non-trivial object filters.
2. If we can compute the traversal with bitmaps, partition the
(dereferenced) tips into two object lists, "haves", and "wants",
based on whether or not the objects have the UNINTERESTING flag,
respectively.
3. Fall back to the ordinary object traversal if either (a) there are
more than zero haves, none of which are in the bitmapped pack or
MIDX, or (b) there are no wants.
4. Construct a reachability bitmap for the "haves" side by walking
from the revision tips down to any existing bitmaps, OR-ing in any
bitmaps as they are found.
5. Then do the same for the "wants" side, stopping at any objects that
appear in the "haves" bitmap.
6. Filter the results if any object filter (that can be easily
computed with bitmaps alone) was given, and then return back to the
caller.
When there is good bitmap coverage relative to the traversal tips, this
walk is often significantly faster than an ordinary object traversal
because it can visit far fewer objects.
But in certain cases, it can be significantly *slower* than the usual
object traversal. Why? Because we need to compute complete bitmaps on
either side of the walk. If either one (or both) of the sides require
walking many (or all!) objects before they get to an existing bitmap,
the extra bitmap machinery is mostly or all overhead.
One of the benefits, however, is that even if the walk is slower, bitmap
traversals are guaranteed to provide an *exact* answer. Unlike the
traditional object traversal algorithm, which can over-count the results
by not opening trees for older commits, the bitmap walk builds an exact
reachability bitmap for either side, meaning the results are never
over-counted.
But producing non-exact results is OK for our traversal here (both in
the bitmap case and not), as long as the results are over-counted, not
under.
Relaxing the bitmap traversal to allow it to produce over-counted
results gives us the opportunity to make some significant improvements.
Instead of the above, the new algorithm only has to walk from the
*boundary* down to the nearest bitmap, instead of from each of the
UNINTERESTING tips.
The boundary-based approach still has degenerate cases, but we'll show
in a moment that it is often a significant improvement.
The new algorithm works as follows:
1. Build a (partial) bitmap of the haves side by first OR-ing any
bitmap(s) that already exist for UNINTERESTING commits between the
haves and the boundary.
2. For each commit along the boundary, add it as a fill-in traversal
tip (where the traversal terminates once an existing bitmap is
found), and perform fill-in traversal.
3. Build up a complete bitmap of the wants side as usual, stopping any
time we intersect the (partial) haves side.
4. Return the results.
And is more-or-less equivalent to using the *old* algorithm with this
invocation:
The new result performs significantly better in many cases, particularly
when the distance from the boundary commit(s) to an existing bitmap is
shorter than the distance from (all of) the have tips to the nearest
bitmapped commit.
Note that when using the old bitmap traversal algorithm, the results can
be *slower* than without bitmaps! Under the new algorithm, the result is
computed faster with bitmaps than without (at the cost of over-counting
the true number of objects in a similar fashion as the non-bitmap
traversal):
# (Computing the number of tagged objects not on any branches
# without bitmaps).
$ time git rev-list --count --objects --tags --not --branches
20
real 0m1.388s
user 0m1.092s
sys 0m0.296s
# (Computing the same query using the old bitmap traversal).
$ time git rev-list --count --objects --tags --not --branches --use-bitmap-index
19
The new algorithm is still slower than not using bitmaps at all, but it
is nearly a 15-fold improvement over the existing traversal.
In a more realistic setting (using my local copy of git.git), I can
observe a similar (if more modest) speed-up:
$ argv="--count --objects --branches --not --tags"
hyperfine \
-n 'no bitmaps' "git.compile rev-list $argv" \
-n 'existing traversal' "git.compile rev-list --use-bitmap-index $argv" \
-n 'boundary traversal' "git.compile -c pack.useBitmapBoundaryTraversal=true rev-list --use-bitmap-index $argv"
Benchmark 1: no bitmaps
Time (mean ± σ): 124.6 ms ± 2.1 ms [User: 103.7 ms, System: 20.8 ms]
Range (min … max): 122.6 ms … 133.1 ms 22 runs
Benchmark 2: existing traversal
Time (mean ± σ): 368.6 ms ± 3.0 ms [User: 325.3 ms, System: 43.1 ms]
Range (min … max): 365.1 ms … 374.8 ms 10 runs
Benchmark 3: boundary traversal
Time (mean ± σ): 167.6 ms ± 0.9 ms [User: 139.5 ms, System: 27.9 ms]
Range (min … max): 166.1 ms … 169.2 ms 17 runs
Summary
'no bitmaps' ran
1.34 ± 0.02 times faster than 'boundary traversal'
2.96 ± 0.05 times faster than 'existing traversal'
Here, the new algorithm is also still slower than not using bitmaps, but
represents a more than 2-fold improvement over the existing traversal in
a more modest example.
Since this algorithm was originally written (nearly a year and a half
ago, at the time of writing), the bitmap lookup table shipped, making
the new algorithm's result more competitive. A few other future
directions for improving bitmap traversal times beyond not using bitmaps
at all:
- Decrease the cost to decompress and OR together many bitmaps
together (particularly when enumerating the uninteresting side of
the walk). Here we could explore more efficient bitmap storage
techniques, like Roaring+Run and/or use SIMD instructions to speed
up ORing them together.
- Store pseudo-merge bitmaps, which could allow us to OR together
fewer "summary" bitmaps (which would also help with the above).
Helped-by: Jeff King <peff@peff.net> Helped-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Mon, 8 May 2023 17:38:09 +0000 (13:38 -0400)]
pack-bitmap.c: extract `fill_in_bitmap()`
To prepare for the boundary-based bitmap walk to perform a fill-in
traversal using the boundary of either side as the tips, extract routine
used to perform fill-in traversal by `find_objects()` so that it can be
used in both places.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Fri, 28 Apr 2023 23:03:03 +0000 (16:03 -0700)]
Merge branch 'tb/enable-cruft-packs-by-default'
When "gc" needs to retain unreachable objects, packing them into
cruft packs (instead of exploding them into loose object files) has
been offered as a more efficient option for some time. Now the use
of cruft packs has been made the default and no longer considered
an experimental feature.
* tb/enable-cruft-packs-by-default:
repository.h: drop unused `gc_cruft_packs`
builtin/gc.c: make `gc.cruftPacks` enabled by default
t/t9300-fast-import.sh: prepare for `gc --cruft` by default
t/t6500-gc.sh: add additional test cases
t/t6500-gc.sh: refactor cruft pack tests
t/t6501-freshen-objects.sh: prepare for `gc --cruft` by default
t/t5304-prune.sh: prepare for `gc --cruft` by default
builtin/gc.c: ignore cruft packs with `--keep-largest-pack`
builtin/repack.c: fix incorrect reference to '-C'
pack-write.c: plug a leak in stage_tmp_packfiles()
Junio C Hamano [Thu, 27 Apr 2023 23:00:59 +0000 (16:00 -0700)]
Merge branch 'tb/pack-revindex-on-disk'
The on-disk reverse index that allows mapping from the pack offset
to the object name for the object stored at the offset has been
enabled by default.
* tb/pack-revindex-on-disk:
t: invert `GIT_TEST_WRITE_REV_INDEX`
config: enable `pack.writeReverseIndex` by default
pack-revindex: introduce `pack.readReverseIndex`
pack-revindex: introduce GIT_TEST_REV_INDEX_DIE_ON_DISK
pack-revindex: make `load_pack_revindex` take a repository
t5325: mark as leak-free
pack-write.c: plug a leak in stage_tmp_packfiles()
Junio C Hamano [Tue, 25 Apr 2023 20:56:20 +0000 (13:56 -0700)]
Merge branch 'ps/fix-geom-repack-with-alternates'
Geometric repacking ("git repack --geometric=<n>") in a repository
that borrows from an alternate object database had various corner
case bugs, which have been corrected.
* ps/fix-geom-repack-with-alternates:
repack: disable writing bitmaps when doing a local repack
repack: honor `-l` when calculating pack geometry
t/helper: allow chmtime to print verbosely without modifying mtime
pack-objects: extend test coverage of `--stdin-packs` with alternates
pack-objects: fix error when same packfile is included and excluded
pack-objects: fix error when packing same pack twice
pack-objects: split out `--stdin-packs` tests into separate file
repack: fix generating multi-pack-index with only non-local packs
repack: fix trying to use preferred pack in alternates
midx: fix segfault with no packs and invalid preferred pack
The sendemail-validate validate hook learned to pass the total
number of input files and where in the sequence each invocation is
via environment variables.
* rj/send-email-validate-hook-count-messages:
send-email: export patch counters in validate environment
Junio C Hamano [Tue, 25 Apr 2023 20:56:20 +0000 (13:56 -0700)]
Merge branch 'jk/protocol-cap-parse-fix'
The code to parse capability list for v0 on-wire protocol fell into
an infinite loop when a capability appears multiple times, which
has been corrected.
* jk/protocol-cap-parse-fix:
v0 protocol: use size_t for capability length/offset
t5512: test "ls-remote --heads --symref" filtering with v0 and v2
t5512: allow any protocol version for filtered symref test
t5512: add v2 support for "ls-remote --symref" test
v0 protocol: fix sha1/sha256 confusion for capabilities^{}
t5512: stop referring to "v1" protocol
v0 protocol: fix infinite loop when parsing multi-valued capabilities
Junio C Hamano [Tue, 25 Apr 2023 20:56:19 +0000 (13:56 -0700)]
Merge branch 'en/header-split-cache-h'
Header clean-up.
* en/header-split-cache-h: (24 commits)
protocol.h: move definition of DEFAULT_GIT_PORT from cache.h
mailmap, quote: move declarations of global vars to correct unit
treewide: reduce includes of cache.h in other headers
treewide: remove double forward declaration of read_in_full
cache.h: remove unnecessary includes
treewide: remove cache.h inclusion due to pager.h changes
pager.h: move declarations for pager.c functions from cache.h
treewide: remove cache.h inclusion due to editor.h changes
editor: move editor-related functions and declarations into common file
treewide: remove cache.h inclusion due to object.h changes
object.h: move some inline functions and defines from cache.h
treewide: remove cache.h inclusion due to object-file.h changes
object-file.h: move declarations for object-file.c functions from cache.h
treewide: remove cache.h inclusion due to git-zlib changes
git-zlib: move declarations for git-zlib functions from cache.h
treewide: remove cache.h inclusion due to object-name.h changes
object-name.h: move declarations for object-name.c functions from cache.h
treewide: remove unnecessary cache.h inclusion
treewide: be explicit about dependence on mem-pool.h
treewide: be explicit about dependence on oid-array.h
...
Junio C Hamano [Fri, 21 Apr 2023 22:35:05 +0000 (15:35 -0700)]
Merge branch 'ow/ref-filter-omit-empty'
"git branch --format=..." and "git format-patch --format=..."
learns "--omit-empty" to hide refs that whose formatting result
becomes an empty string from the output.
"git clone --local" stops copying from an original repository that
has symbolic links inside its $GIT_DIR; an error message when that
happens has been updated.
* gc/better-error-when-local-clone-fails-with-symlink:
clone: error specifically with --local and symlinked objects
Junio C Hamano [Thu, 20 Apr 2023 21:33:35 +0000 (14:33 -0700)]
Merge branch 'rs/userdiff-multibyte-regex'
The userdiff regexp patterns for various filetypes that are built
into the system have been updated to avoid triggering regexp errors
from UTF-8 aware regex engines.
* rs/userdiff-multibyte-regex:
userdiff: support regexec(3) with multi-byte support
Felipe Contreras [Tue, 18 Apr 2023 07:00:48 +0000 (01:00 -0600)]
doc: git-checkout: reorganize examples
The examples are an ordered list, however, they are complex enough that
a callout is inside example 1, and that confuses the parsers as the list
continuation (`+`) is unclear (are we continuing the previous list item,
or the previous callout?).
We could use an open block as the asciidoctor documentation suggests,
but that has a tiny formatting issue (a newline is missing).
To simplify things for everyone (the reader, the writer, and the parser)
let's use subsections.
After this change, the HTML documentation generated with asciidoc has
the right indentation.
Cc: Jeff King <peff@peff.net> Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Tue, 18 Apr 2023 20:41:00 +0000 (16:41 -0400)]
repository.h: drop unused `gc_cruft_packs`
As of the previous commit, all callers that need to read the value of
`gc.cruftPacks` do so outside without using the `repo_settings` struct,
making its `gc_cruft_packs` unused. Drop it accordingly.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Tue, 18 Apr 2023 20:40:57 +0000 (16:40 -0400)]
builtin/gc.c: make `gc.cruftPacks` enabled by default
Back in 5b92477f89 (builtin/gc.c: conditionally avoid pruning objects
via loose, 2022-05-20), `git gc` learned the `--cruft` option and
`gc.cruftPacks` configuration to opt-in to writing cruft packs when
collecting or pruning unreachable objects.
Cruft packs were introduced with the merge in a50036da1a (Merge branch
'tb/cruft-packs', 2022-06-03). They address the problem of "loose object
explosions", where Git will write out many individual loose objects when
there is a large number of unreachable objects that have not yet aged
past `--prune=<date>`.
Instead of keeping track of those unreachable yet recent objects via
their loose object file's mtime, cruft packs collect all unreachable
objects into a single pack with a corresponding `*.mtimes` file that
acts as a table to store the mtimes of all unreachable objects. This
prevents the need to store unreachable objects as loose as they age out
of the repository, and avoids the problem of loose object explosions.
Beyond avoiding loose object explosions, cruft packs also act as a more
efficient mechanism to store unreachable objects as they age out of a
repository. This is because pairs of similar unreachable objects serve
as delta bases for one another.
In 5b92477f89, the feature was introduced as experimental. Since then,
GitHub has been running these patches in every repository generating
hundreds of millions of cruft packs along the way. The feature is
battle-tested, and avoids many pathological cases such as above. Users
who either run `git gc` manually, or via `git maintenance` can benefit
from having cruft packs.
As such, enable cruft pack generation to take place by default (by
making `gc.cruftPacks` have the default of "true" rather than "false).
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Tue, 18 Apr 2023 20:40:52 +0000 (16:40 -0400)]
t/t9300-fast-import.sh: prepare for `gc --cruft` by default
In a similar fashion as previous commits, adjust the fast-import tests
to prepare for "git gc" generating a cruft pack by default.
This adjustment is slightly different, however. Instead of relying on us
writing out the objects loose, and then calling `git prune` to remove
them, t9300 needs to be prepared to drop objects that would be moved
into cruft packs.
To do this, we can combine the `git gc` invocation with `git prune` into
one `git gc --prune`, which handles pruning both loose objects, and
objects that would otherwise be written to a cruft pack.
Likely this pattern of "git gc && git prune" started all the way back in 03db4525d3 (Support gitlinks in fast-import., 2008-07-19), which
happened after deprecating `git gc --prune` in 9e7d501990 (builtin-gc.c:
deprecate --prune, it now really has no effect, 2008-05-09).
After `--prune` was un-deprecated in 58e9d9d472 (gc: make --prune useful
again by accepting an optional parameter, 2009-02-14), this script got a
handful of new "git gc && git prune" instances via via 4cedb78cb5
(fast-import: add input format tests, 2011-08-11). These could have been
`git gc --prune`, but weren't (likely taking after 03db4525d3).
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Tue, 18 Apr 2023 20:40:49 +0000 (16:40 -0400)]
t/t6500-gc.sh: add additional test cases
In the last commit, we refactored some of the tests in t6500 to make
clearer when cruft packs will and won't be generated by `git gc`.
Add the remaining cases not covered by the previous patch into this one,
which enumerates all possible combinations of arguments that will
produce (or not produce) a cruft pack.
This prepares us for a future commit which will change the default value
of `gc.cruftPacks` by ensuring that we understand which invocations do
and do not change as a result.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Tue, 18 Apr 2023 20:40:46 +0000 (16:40 -0400)]
t/t6500-gc.sh: refactor cruft pack tests
In 12253ab6d0 (gc: add tests for --cruft and friends, 2022-10-26), we
added a handful of tests to t6500 to ensure that `git gc` respected the
value of `--cruft` and `gc.cruftPacks`.
Then, in c695592850 (config: let feature.experimental imply
gc.cruftPacks=true, 2022-10-26), another set of similar tests was added
to ensure that `feature.experimental` correctly implied enabling cruft
pack generation (or not).
These tests are similar and could be consolidated. Do so in this patch
to prepare for expanding the set of command-line invocations that enable
or disable writing cruft packs. This makes it possible to easily test
more combinations of arguments without being overly repetitive.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Tue, 18 Apr 2023 20:40:43 +0000 (16:40 -0400)]
t/t6501-freshen-objects.sh: prepare for `gc --cruft` by default
In a similar spirit as previous commits, prepare for `gc --cruft`
becoming the default by ensuring that the tests in t6501 explicitly
cover the case of freshening loose objects not using cruft packs.
We could run this test twice, once with `--cruft` and once with
`--no-cruft`, but doing so is unnecessary, since we already test object
rescuing, freshening, and dealing with corrupt parts of the unreachable
object graph extensively via t5329.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Tue, 18 Apr 2023 20:40:41 +0000 (16:40 -0400)]
t/t5304-prune.sh: prepare for `gc --cruft` by default
Many of the tests in t5304 run `git gc`, and rely on its behavior that
unreachable-but-recent objects are written out loose. This is sensible,
since t5304 deals specifically with this kind of pruning.
If left unattended, however, this test would break when the default
behavior of a bare "git gc" is adjusted to generate a cruft pack by
default.
Ensure that these tests continue to work as-is (and continue to provide
coverage of loose object pruning) by passing `--no-cruft` explicitly.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Tue, 18 Apr 2023 20:40:38 +0000 (16:40 -0400)]
builtin/gc.c: ignore cruft packs with `--keep-largest-pack`
When cruft packs were implemented, we never adjusted the code for `git
gc`'s `--keep-largest-pack` and `gc.bigPackThreshold` to ignore cruft
packs. This option and configuration option share a common
implementation, but including cruft packs is wrong in both cases:
- Running `git gc --keep-largest-pack` in a repository where the
largest pack is the cruft pack itself will make it impossible for
`git gc` to prune objects, since the cruft pack itself is kept.
- The same is true for `gc.bigPackThreshold`, if the size of the cruft
pack exceeds the limit set by the caller.
In the future, it is possible that `gc.bigPackThreshold` could be used
to write a separate cruft pack containing any new unreachable objects
that entered the repository since the last time a cruft pack was
written.
There are some complexities to doing so, mainly around handling
pruning objects that are in an existing cruft pack that is above the
threshold (which would either need to be rewritten, or else delay
pruning). Rewriting a substantially similar cruft pack isn't ideal, but
it is significantly better than the status-quo.
If users have large cruft packs that they don't want to rewrite, they
can mark them as `*.keep` packs. But in general, if a repository has a
cruft pack that is so large it is slowing down GC's, it should probably
be pruned anyway.
In the meantime, ignore cruft packs in the common implementation for
both of these options, and add a pair of tests to prevent any future
regressions here.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Tue, 18 Apr 2023 20:40:35 +0000 (16:40 -0400)]
builtin/repack.c: fix incorrect reference to '-C'
When cruft packs were originally being developed, `-C` was designated as
the short-form for `--cruft` (as in `git repack -C`).
This was dropped due to confusion with Git's top-level `-C` option
before submitting to the list. But the reference to it in
`--cruft-expiration`'s help text was never updated. Fix that dangling
reference in this patch.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Tue, 18 Apr 2023 20:40:32 +0000 (16:40 -0400)]
pack-write.c: plug a leak in stage_tmp_packfiles()
The function `stage_tmp_packfiles()` generates a filename to use for
staging the contents of what will become the pack's ".mtimes" file.
The name is generated in `write_mtimes_file()` and the result is
returned back to `stage_tmp_packfiles()` which uses it to rename the
temporary file into place via `rename_tmp_packfiles()`.
`write_mtimes_file()` returns a `const char *`, indicating that callers
are not expected to free its result (similar to, e.g., `oid_to_hex()`).
But callers are expected to free its result, so this return type is
incorrect.
Change the function's signature to return a non-const `char *`, and free
it at the end of `stage_tmp_packfiles()`.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
protocol.h: move definition of DEFAULT_GIT_PORT from cache.h
Michael J Gruber noticed that connection via the git:// protocol no
longer worked after a recent header clean-up. This was caused by
funny interaction of few gotchas. First, a necessary definition
#define DEFAULT_GIT_PORT 9418
was made invisible to a place where
const char *port = STR(DEFAULT_GIT_PORT);
was expecting to turn the integer into "9418" with a clever STR()
macro, and ended up stringifying it to
const char *port = "DEFAULT_GIT_PORT";
without giving any chance to compilers to notice such a mistake.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Clean-up of the code path that deals with merge strategy option
handling in "git rebase".
* pw/rebase-cleanup-merge-strategy-option-handling:
rebase: remove a couple of redundant strategy tests
rebase -m: fix serialization of strategy options
rebase -m: cleanup --strategy-option handling
sequencer: use struct strvec to store merge strategy options
rebase: stop reading and writing unnecessary strategy state
"git branch -d origin/master" would say "no such branch", but it is
likely a missed "-r" if refs/remotes/origin/master exists. The
command has been taught to give such a hint in its error message.
* cm/branch-delete-error-message-update:
branch: improve error log on branch not found by checking remotes refs
Junio C Hamano [Tue, 18 Apr 2023 01:05:11 +0000 (18:05 -0700)]
Merge branch 'tk/mergetool-gui-default-config'
"git mergetool" and "git difftool" learns a new configuration
guiDefault to optionally favor configured guitool over non-gui-tool
automatically when $DISPLAY is set.
* tk/mergetool-gui-default-config:
mergetool: new config guiDefault supports auto-toggling gui by DISPLAY
While parsing a .rev file, we check the header information to be sure it
makes sense. This happens before doing any additional validation such as
a checksum or value check. In order to differentiate between a bad
header and a non-existent file, we need to update the API for loading a
reverse index.
Make load_pack_revindex_from_disk() non-static and specify that a
positive value means "the file does not exist" while other errors during
parsing are negative values. Since an invalid header prevents setting up
the structures we would use for further validations, we can stop at that
point.
The place where we can distinguish between a missing file and a corrupt
file is inside load_revindex_from_disk(), which is used both by pack
rev-indexes and multi-pack-index rev-indexes. Some tests in t5326
demonstrate that it is critical to take some conditions to allow
positive error signals.
Add tests that check the three header values.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When checking a rev-index file, it may be helpful to identify exactly
which positions are incorrect. Compare the rev-index to a
freshly-computed in-memory rev-index and report the comparison failures.
This additional check (on top of the checksum validation) can help find
files that were corrupt by a single bit flip on-disk or perhaps were
written incorrectly due to a bug in Git.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous change added calls to verify_pack_revindex() in
builtin/fsck.c, but the implementation of the method was left empty. Add
the first and most-obvious check to this method: checksum verification.
While here, create a helper method in the test script that makes it easy
to adjust the .rev file and check that 'git fsck' reports the correct
error message.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
The 'fsck' builtin checks many of Git's on-disk data structures, but
does not currently validate the pack rev-index files (a .rev file to
pair with a .pack and .idx file).
Before doing a more-involved check process, create the scaffolding
within builtin/fsck.c to have a new error type and add that error type
when the API method verify_pack_revindex() returns an error. That method
does nothing currently, but we will add checks to it in later changes.
For now, check that 'git fsck' succeeds without any errors in the normal
case. Future checks will be paired with tests that corrupt the .rev file
appropriately.
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Mon, 17 Apr 2023 21:38:59 +0000 (14:38 -0700)]
Merge branch 'tb/pack-revindex-on-disk' into ds/fsck-pack-revindex
* tb/pack-revindex-on-disk:
t: invert `GIT_TEST_WRITE_REV_INDEX`
config: enable `pack.writeReverseIndex` by default
pack-revindex: introduce `pack.readReverseIndex`
pack-revindex: introduce GIT_TEST_REV_INDEX_DIE_ON_DISK
pack-revindex: make `load_pack_revindex` take a repository
t5325: mark as leak-free
pack-write.c: plug a leak in stage_tmp_packfiles()
* maint-2.39: (34 commits)
Git 2.39.3
Git 2.38.5
Git 2.37.7
Git 2.36.6
Git 2.35.8
Makefile: force -O0 when compiling with SANITIZE=leak
Git 2.34.8
Git 2.33.8
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
range-diff: use ssize_t for parsed "len" in read_patches()
...
* maint-2.38: (32 commits)
Git 2.38.5
Git 2.37.7
Git 2.36.6
Git 2.35.8
Git 2.34.8
Git 2.33.8
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
...
* maint-2.37: (31 commits)
Git 2.37.7
Git 2.36.6
Git 2.35.8
Git 2.34.8
Git 2.33.8
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
...
* maint-2.36: (30 commits)
Git 2.36.6
Git 2.35.8
Git 2.34.8
Git 2.33.8
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
t0033: GETTEXT_POISON fix
...
* maint-2.35: (29 commits)
Git 2.35.8
Git 2.34.8
Git 2.33.8
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
t0033: GETTEXT_POISON fix
http: support CURLOPT_PROTOCOLS_STR
...
* maint-2.34: (28 commits)
Git 2.34.8
Git 2.33.8
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
t0033: GETTEXT_POISON fix
http: support CURLOPT_PROTOCOLS_STR
http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
...
* maint-2.33: (27 commits)
Git 2.33.8
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
t0033: GETTEXT_POISON fix
http: support CURLOPT_PROTOCOLS_STR
http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
http-push: prefer CURLOPT_UPLOAD to CURLOPT_PUT
...
* maint-2.32: (26 commits)
Git 2.32.7
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
t0033: GETTEXT_POISON fix
http: support CURLOPT_PROTOCOLS_STR
http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
http-push: prefer CURLOPT_UPLOAD to CURLOPT_PUT
ci: install python on ubuntu
...
* maint-2.31: (25 commits)
Git 2.31.8
tests: avoid using `test_i18ncmp`
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
t0033: GETTEXT_POISON fix
http: support CURLOPT_PROTOCOLS_STR
http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
http-push: prefer CURLOPT_UPLOAD to CURLOPT_PUT
ci: install python on ubuntu
ci: use the same version of p4 on both Linux and macOS
...
* maint-2.30: (23 commits)
Git 2.30.9
gettext: avoid using gettext if the locale dir is not present
apply --reject: overwrite existing `.rej` symlink if it exists
http.c: clear the 'finished' member once we are done with it
clone.c: avoid "exceeds maximum object size" error with GCC v12.x
range-diff: use ssize_t for parsed "len" in read_patches()
range-diff: handle unterminated lines in read_patches()
range-diff: drop useless "offset" variable from read_patches()
t5604: GETTEXT_POISON fix, conclusion
t5604: GETTEXT_POISON fix, part 1
t5619: GETTEXT_POISON fix
t0003: GETTEXT_POISON fix, conclusion
t0003: GETTEXT_POISON fix, part 1
t0033: GETTEXT_POISON fix
http: support CURLOPT_PROTOCOLS_STR
http: prefer CURLOPT_SEEKFUNCTION to CURLOPT_IOCTLFUNCTION
http-push: prefer CURLOPT_UPLOAD to CURLOPT_PUT
ci: install python on ubuntu
ci: use the same version of p4 on both Linux and macOS
ci: remove the pipe after "p4 -V" to catch errors
github-actions: run gcc-8 on ubuntu-20.04 image
...
Avoids issues with renaming or deleting sections with long lines, where
configuration values may be interpreted as sections, leading to
configuration injection. Addresses CVE-2023-29007.
* tb/config-copy-or-rename-in-file-injection:
config.c: disallow overly-long lines in `copy_or_rename_section_in_file()`
config.c: avoid integer truncation in `copy_or_rename_section_in_file()`
config: avoid fixed-sized buffer when renaming/deleting a section
t1300: demonstrate failure when renaming sections with long lines
Taylor Blau [Wed, 12 Apr 2023 23:18:28 +0000 (19:18 -0400)]
config.c: disallow overly-long lines in `copy_or_rename_section_in_file()`
As a defense-in-depth measure to guard against any potentially-unknown
buffer overflows in `copy_or_rename_section_in_file()`, refuse to work
with overly-long lines in a gitconfig.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Taylor Blau [Thu, 6 Apr 2023 18:28:53 +0000 (14:28 -0400)]
config.c: avoid integer truncation in `copy_or_rename_section_in_file()`
There are a couple of spots within `copy_or_rename_section_in_file()`
that incorrectly use an `int` to track an offset within a string, which
may truncate or wrap around to a negative value.
Historically it was impossible to have a line longer than 1024 bytes
anyway, since we used fgets() with a fixed-size buffer of exactly that
length. But the recent change to use a strbuf permits us to read lines
of arbitrary length, so it's possible for a malicious input to cause us
to overflow past INT_MAX and do an out-of-bounds array read.
Practically speaking, however, this should never happen, since it
requires 2GB section names or values, which are unrealistic in
non-malicious circumstances.
Co-authored-by: Jeff King <peff@peff.net> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com>
Taylor Blau [Thu, 6 Apr 2023 18:07:58 +0000 (14:07 -0400)]
config: avoid fixed-sized buffer when renaming/deleting a section
When renaming (or deleting) a section of configuration, Git uses the
function `git_config_copy_or_rename_section_in_file()` to rewrite the
configuration file after applying the rename or deletion to the given
section.
To do this, Git repeatedly calls `fgets()` to read the existing
configuration data into a fixed size buffer.
When the configuration value under `old_name` exceeds the size of the
buffer, we will call `fgets()` an additional time even if there is no
newline in the configuration file, since our read length is capped at
`sizeof(buf)`.
If the first character of the buffer (after zero or more characters
satisfying `isspace()`) is a '[', Git will incorrectly treat it as
beginning a new section when the original section is being removed. In
other words, a configuration value satisfying this criteria can
incorrectly be considered as a new secftion instead of a variable in the
original section.
Avoid this issue by using a variable-width buffer in the form of a
strbuf rather than a fixed-with region on the stack. A couple of small
points worth noting:
- Using a strbuf will cause us to allocate arbitrary sizes to match
the length of each line. In practice, we don't expect any
reasonable configuration files to have lines that long, and a
bandaid will be introduced in a later patch to ensure that this is
the case.
- We are using strbuf_getwholeline() here instead of strbuf_getline()
in order to match `fgets()`'s behavior of leaving the trailing LF
character on the buffer (as well as a trailing NUL).
This could be changed later, but using strbuf_getwholeline() changes
the least about this function's implementation, so it is picked as
the safest path.
- It is temping to want to replace the loop to skip over characters
matching isspace() at the beginning of the buffer with a convenience
function like `strbuf_ltrim()`. But this is the wrong approach for a
couple of reasons:
First, it involves a potentially large and expensive `memmove()`
which we would like to avoid. Second, and more importantly, we also
*do* want to preserve those spaces to avoid changing the output of
other sections.
In all, this patch is a minimal replacement of the fixed-width buffer in
`git_config_copy_or_rename_section_in_file()` to instead use a `struct
strbuf`.
Reported-by: André Baptista <andre@ethiack.com> Reported-by: Vítor Pinho <vitor@ethiack.com> Helped-by: Patrick Steinhardt <ps@pks.im> Co-authored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Taylor Blau <me@ttaylorr.com>
gettext: avoid using gettext if the locale dir is not present
In cc5e1bf99247 (gettext: avoid initialization if the locale dir is not
present, 2018-04-21) Git was taught to avoid a costly gettext start-up
when there are not even any localized messages to work with.
But we still called `gettext()` and `ngettext()` functions.
Which caused a problem in Git for Windows when the libgettext that is
consumed from the MSYS2 project stopped using a runtime prefix in
https://github.com/msys2/MINGW-packages/pull/10461
Due to that change, we now use an unintialized gettext machinery that
might get auto-initialized _using an unintended locale directory_:
`C:\mingw64\share\locale`.
Let's record the fact when the gettext initialization was skipped, and
skip calling the gettext functions accordingly.
This addresses CVE-2023-25815.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Taylor Blau [Thu, 6 Apr 2023 15:42:03 +0000 (11:42 -0400)]
t1300: demonstrate failure when renaming sections with long lines
When renaming a configuration section which has an entry whose length
exceeds the size of our buffer in config.c's implementation of
`git_config_copy_or_rename_section_in_file()`, Git will incorrectly
form a new configuration section with part of the data in the section
being removed.
In this instance, our first configuration file looks something like:
[b]
c = d <spaces> [a] e = f
[a]
g = h
Here, we have two configuration values, "b.c", and "a.g". The value "[a]
e = f" belongs to the configuration value "b.c", and does not form its
own section.
However, when renaming the section 'a' to 'xyz', Git will write back
"[xyz]\ne = f", but "[xyz]" is still attached to the value of "b.c",
which is why "e = f" on its own line becomes a new entry called "b.e".
A slightly different example embeds the section being renamed within
another section.
Demonstrate this failure in a test in t1300, which we will fix in the
following commit.
Co-authored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Taylor Blau <me@ttaylorr.com>
apply --reject: overwrite existing `.rej` symlink if it exists
The `git apply --reject` is expected to write out `.rej` files in case
one or more hunks fail to apply cleanly. Historically, the command
overwrites any existing `.rej` files. The idea being that
apply/reject/edit cycles are relatively common, and the generated `.rej`
files are not considered precious.
But the command does not overwrite existing `.rej` symbolic links, and
instead follows them. This is unsafe because the same patch could
potentially create such a symbolic link and point at arbitrary paths
outside the current worktree, and `git apply` would write the contents
of the `.rej` file into that location.
Therefore, let's make sure that any existing `.rej` file or symbolic
link is removed before writing it.
Reported-by: RyotaK <ryotak.mail@gmail.com> Helped-by: Taylor Blau <me@ttaylorr.com> Helped-by: Junio C Hamano <gitster@pobox.com> Helped-by: Linus Torvalds <torvalds@linuxfoundation.org> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The `maint-2.30` branch accumulated quite a few fixes over the past two
years. Most of those fixes were originally based on newer versions, and
while the patches cherry-picked cleanly, we weren't diligent enough to
pay attention to the CI builds and the GETTEXT_POISON job regressed.
This topic branch fixes that.
Derrick Stolee [Tue, 23 Aug 2022 17:28:11 +0000 (17:28 +0000)]
ci: update 'static-analysis' to Ubuntu 22.04
GitHub Actions scheduled a brownout of Ubuntu 18.04, which canceled all
runs of the 'static-analysis' job in our CI runs. Update to 22.04 to
avoid this as the brownout later turns into a complete deprecation.
The use of 18.04 was set in d051ed77ee6 (.github/workflows/main.yml: run
static-analysis on bionic, 2021-02-08) due to the lack of Coccinelle
being available on 20.04 (which continues today).
Signed-off-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Fri, 14 Apr 2023 21:25:20 +0000 (17:25 -0400)]
v0 protocol: use size_t for capability length/offset
When parsing server capabilities, we use "int" to store lengths and
offsets. At first glance this seems like a spot where our parser may be
confused by integer overflow if somebody sent us a malicious response.
In practice these strings are all bounded by the 64k limit of a
pkt-line, so using "int" is OK. However, it makes the code simpler to
audit if they just use size_t everywhere. Note that because we take
these parameters as pointers, this also forces many callers to update
their declared types.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Fri, 14 Apr 2023 21:25:18 +0000 (17:25 -0400)]
t5512: test "ls-remote --heads --symref" filtering with v0 and v2
We have two overlapping tests for checking the behavior of "ls-remote
--symref" when filtering output. The first test checks that using
"--heads" will omit the symref for HEAD (since we don't print anything
about HEAD at all), but still prints other symrefs.
This has been marked as expecting failure since it was added in 99c08d4eb2 (ls-remote: add support for showing symrefs, 2016-01-19).
That's because back then, we only had the v0 protocol, and it only
reported on the HEAD symref, not others. But these days we have v2,
which does exactly what the test wants. It would even have started
unexpectedly passing when we switched to v2 by default, except that b2f73b70b2 (t5512: compensate for v0 only sending HEAD symrefs,
2019-02-25) over-zealously marked it to run only in v0 mode.
So let's run it with both protocol versions, and adjust the expected
output for each. It passes in v2 without modification. In v0 mode, we'll
drop the extra symref, but this is still testing something useful: it
ensures that we do omit HEAD.
The test after this checks "--heads" again, this time using the expected
v0 output. That's now redundant. It also checks that limiting with a
pattern like "refs/heads/*" works similarly, but that's redundant with a
test earlier in the script which limits by HEAD (again, back then the
"HEAD" test was less interesting because there were no other symrefs to
omit, but in a modern v2 world, there are). So we can just delete that
second test entirely.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Fri, 14 Apr 2023 21:25:16 +0000 (17:25 -0400)]
t5512: allow any protocol version for filtered symref test
We have a test that checks that ls-remote, when asked only about HEAD,
will report the HEAD symref, and not others. This was marked to always
run with the v0 protocol by b2f73b70b2 (t5512: compensate for v0 only
sending HEAD symrefs, 2019-02-25).
But in v0 this test is doing nothing! For v0, upload-pack only reports
the HEAD symref anyway, so we'd never have any other symref to report.
For v2, it is useful; we learn about all symrefs (and the test repo has
multiple), so this demonstrates that we correctly avoid showing them.
We could perhaps mark this to test explicitly with v2, but since that is
the default these days, it's sufficient to just run ls-remote without
any protocol specification. It still passes if somebody does an explicit
GIT_TEST_PROTOCOL_VERSION=0; it's just testing less.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Fri, 14 Apr 2023 21:25:13 +0000 (17:25 -0400)]
t5512: add v2 support for "ls-remote --symref" test
Commit b2f73b70b2 (t5512: compensate for v0 only sending HEAD symrefs,
2019-02-25) configured this test to always run with protocol v0, since
the output is different for v2.
But that means we are not getting any test coverage of the feature with
v2 at all. We could obviously switch to using and expecting v2, but then
that leaves v0 behind (and while we don't use it by default, it's still
important for testing interoperability with older servers). Likewise, we
could switch the expected output based on $GIT_TEST_PROTOCOL_VERSION,
but hardly anybody runs the tests for v0 these days.
Instead, let's explicitly run it for both protocol versions to make sure
they're well behaved. This matches other similar tests added later in 6a139cdd74 (ls-remote: pass heads/tags prefixes to transport,
2018-10-31), etc.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
followed by a NUL and the actual capabilities. We correctly parse the
oid using the packet_reader's hash_algo field, but then we compare it to
null_oid(), which will instead use our current repo's default algorithm.
If we're defaulting to sha256 locally but the other side is sha1, they
won't match and we'll fail to parse the line (and thus die()).
This can cause a test failure when the suite is run with
GIT_TEST_DEFAULT_HASH=sha256, and we even do so regularly via the
linux-sha256 CI job. But since the test requires JGit to run, it's
usually just skipped, and nobody noticed the problem.
The reason the original patch used JGit is that Git itself does not ever
produce such a line via upload-pack; the feature was added to fix a
real-world problem when interacting with JGit. That was good for
verifying that the incompatibility was fixed, but it's not a good
regression test:
- hardly anybody runs it, because you have to have jgit installed;
hence this bug going unnoticed
- we're depending on jgit's behavior for the test to do anything
useful. In particular, this behavior is only relevant to the v0
protocol, but these days we ask for the v2 protocol by default. So
for modern jgit, this is probably testing nothing.
- it's complicated and slow. We had to do some fifo trickery to handle
races, and this one test makes up 40% of the runtime of the total
script.
Instead, let's just hard-code the response that's of interest to us.
That will test exactly what we want for every run, and reveals the bug
when run in sha256 mode. And of course we'll fix the actual bug by using
the correct hash_algo struct.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Fri, 14 Apr 2023 21:24:19 +0000 (17:24 -0400)]
t5512: stop referring to "v1" protocol
There really isn't a "v1" Git protocol. It's just v0 with an extra probe
which we used to test compatibility in preparation for v2. Any tests
that are looking for before/after behavior for v2 really care about
"v0". Mentioning "v1" in these tests is just making things more
confusing, because we don't care about that probe; we're really testing
v0. So let's say so.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Fri, 14 Apr 2023 21:24:16 +0000 (17:24 -0400)]
v0 protocol: fix infinite loop when parsing multi-valued capabilities
If Git's client-side parsing of an upload-pack response (so git-fetch or
ls-remote) sees multiple instances of a single capability, it can enter
an infinite loop due to a bug in advancing the "offset" parameter in the
parser.
This bug can't happen between a client and server of the same Git
version. The client bug is in parse_feature_value() when the caller
passes in an offset parameter. And that only happens when the v0
protocol is parsing "symref" and "object-format" capabilities, via
next_server_feature_value(). But Git has never produced multiple
object-format capabilities, and it stopped producing multiple symref
values in d007dbf7d6 (Revert "upload-pack: send non-HEAD symbolic refs",
2013-11-18).
However, upload-pack did produce multiple symref entries for a while,
and they are valid. Plus other implementations, such as Dulwich will
still do so. So we should handle them. And even if we do not expect it,
it is obviously a bug for the parser to enter an infinite loop.
The bug itself is pretty simple. Commit 2c6a403d96 (connect: add
function to parse multiple v1 capability values, 2020-05-25) added the
"offset" parameter, which is used as both an in- and out-parameter. When
parsing the first "symref" capability, *offset will be 0 on input, and
after parsing the capability, we set *offset to an index just past the
value by taking a pointer difference "(value + end) - feature_list".
But on the second call, now *offset is set to that larger index, which
lets us skip past the first "symref" capability. However, we do so by
incrementing feature_list. That means our pointer difference is now too
small; it is counting from where we resumed parsing, not from the start
of the original feature_list pointer. And because we incremented
feature_list only inside our function, and not the caller, that
increment is lost next time the function is called.
One solution would be to account for those skipped bytes by incrementing
*offset, rather than assigning to it. But wait, there's more!
We also increment feature_list if we have a near-miss. Say we are
looking for "symref" and find "almost-symref". In that case we'll point
feature_list to the "y" in "almost-symref" and restart our search. But
that again means our offset won't be correct, as it won't account for
the bytes between the start of the string and that "y".
So instead, let's just record the beginning of the feature_list string
in a separate pointer that we never touch. That offset we take in and
return is meant to be using that point as a base, and now we'll do so
consistently.
Since the bug can't be reproduced using the current version of
git-upload-pack, we'll instead hard-code an input which triggers the
problem. Before this patch it loops forever re-parsing the second symref
entry. Now we check both that it finishes, and that it parses both
entries correctly (a case we could not test at all before).
We don't need to worry about testing v2 here; it communicates the
capabilities in a completely different way, and doesn't use this code at
all. There are tests earlier in t5512 that are meant to cover this (they
don't, but we'll address that in a future patch).
Reported-by: Jonas Haag <jonas@lophus.org> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Robin Jarry [Fri, 14 Apr 2023 15:52:49 +0000 (17:52 +0200)]
send-email: export patch counters in validate environment
When sending patch series (with a cover-letter or not)
sendemail-validate is called with every email/patch file independently
from the others. When one of the patches depends on a previous one, it
may not be possible to use this hook in a meaningful way. A hook that
wants to check some property of the whole series needs to know which
patch is the final one.
Expose the current and total number of patches to the hook via the
GIT_SENDEMAIL_PATCH_COUNTER and GIT_SENDEMAIL_PATCH_TOTAL environment
variables so that both incremental and global validation is possible.
Sharing any other state between successive invocations of the validate
hook must be done via external means. For example, by storing it in
a git config sendemail.validateWorktree entry.
Add a sample script with placeholder validations and update tests to
check that the counters are properly exported.
Suggested-by: Phillip Wood <phillip.wood123@gmail.com> Signed-off-by: Robin Jarry <robin@jarry.cc> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Felipe Contreras [Thu, 13 Apr 2023 07:47:22 +0000 (01:47 -0600)]
doc: set actual revdate for manpages
manpages expect the date of the last revision, if that is not found
DocBook Stylesheets go through a series of hacks to generate one with
the format `%d/%d/%Y` which is not ideal.
In addition to this format not being standard, different tools generate
dates with different formats.
There's no need for any confusion if we specify the revision date, so
let's do so.
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
repack: disable writing bitmaps when doing a local repack
In order to write a bitmap, we need to have full coverage of all objects
that are about to be packed. In the traditional non-multi-pack-index
world this meant we need to do a full repack of all objects into a
single packfile. But in the new multi-pack-index world we can get away
with writing bitmaps when we have multiple packfiles as long as the
multi-pack-index covers all objects.
This is not always the case though. When asked to perform a repack of
local objects, only, then we cannot guarantee to have full coverage of
all objects regardless of whether we do a full repack or a repack with a
multi-pack-index. The end result is that writing the bitmap will fail in
both worlds:
$ git multi-pack-index write --stdin-packs --bitmap <packfiles
warning: Failed to write bitmap index. Packfile doesn't have full closure (object 1529341d78cf45377407369acb0f4ff2b5cdae42 is missing)
error: could not write multi-pack bitmap
Now there are two different ways to fix this. The first one would be to
amend git-multi-pack-index(1) to disable writing bitmaps when we notice
that we don't have full object coverage.
- We don't have enough information in git-multi-pack-index(1) in
order to tell whether the local repository _should_ have full
coverage. Because even when connected to an alternate object
directory, it may be the case that we still have all objects
around in the main object database.
- git-multi-pack-index(1) is quite a low-level tool. Automatically
disabling functionality that it was asked to provide does not feel
like the right thing to do.
We can easily fix it at a higher level in git-repack(1) though. When
asked to only include local objects via `-l` and when connected to an
alternate object directory then we will override the user's ask and
disable writing bitmaps with a warning. This is similar to what we do in
git-pack-objects(1), where we also disable writing bitmaps in case we
omit an object from the pack.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the user passes `-l` to git-repack(1), then they essentially ask us
to only repack objects part of the local object database while ignoring
any packfiles part of an alternate object database. And we in fact honor
this bit when doing a geometric repack as the resulting packfile will
only ever contain local objects.
What we're missing though is that we don't take locality of packfiles
into account when computing whether the geometric sequence is intact or
not. So even though we would only ever roll up local packfiles anyway,
we could end up trying to repack because of non-local packfiles. This
does not make much sense, and in the worst case it can cause us to try
and do the geometric repack over and over again because we're never able
to restore the geometric sequence.
Fix this bug by honoring whether the user has passed `-l`. If so, we
skip adding any non-local packfiles to the pack geometry.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
t/helper: allow chmtime to print verbosely without modifying mtime
The `test-tool chmtime` helper allows us to both read and modify the
modification time of files. But while it is possible to only read the
mtimes of a file via `--get`, it is not possible to read the mtimes
and report them together with their respective file paths via the
`--verbose` flag without also modifying the mtime at the same time.
Fix this so that it is possible to call `test-tool chmtime --verbose
<files>...` without modifying any mtimes.
Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
projects / thirdparty / git.git / log
