Taylor Blau [Wed, 7 Jun 2023 22:58:17 +0000 (18:58 -0400)]
gc: introduce `gc.recentObjectsHook`
This patch introduces a new multi-valued configuration option,
`gc.recentObjectsHook` as a means to mark certain objects as recent (and
thus exempt from garbage collection), regardless of their age.
When performing a garbage collection operation on a repository with
unreachable objects, Git makes its decision on what to do with those
object(s) based on how recent the objects are or not. Generally speaking,
unreachable-but-recent objects stay in the repository, and older objects
are discarded.
However, we have no convenient way to keep certain precious, unreachable
objects around in the repository, even if they have aged out and would
be pruned. Our options today consist of:
- Point references at the reachability tips of any objects you
consider precious, which may be undesirable or infeasible if there
are many such objects.
- Track them via the reflog, which may be undesirable since the
reflog's lifetime is limited to that of the reference it's tracking
(and callers may want to keep those unreachable objects around for
longer).
- Extend the grace period, which may keep around other objects that
the caller *does* want to discard.
- Manually modify the mtimes of objects you want to keep. If those
objects are already loose, this is easy enough to do (you can just
enumerate and `touch -m` each one).
But if they are packed, you will either end up modifying the mtimes
of *all* objects in that pack, or be forced to write out a loose
copy of that object, both of which may be undesirable. Even worse,
if they are in a cruft pack, that requires modifying its `*.mtimes`
file by hand, since there is no exposed plumbing for this.
- Force the caller to construct the pack of objects they want
to keep themselves, and then mark the pack as kept by adding a
".keep" file. This works, but is burdensome for the caller, and
having extra packs is awkward as you roll forward your cruft pack.
This patch introduces a new option to the above list via the
`gc.recentObjectsHook` configuration, which allows the caller to
specify a program (or set of programs) whose output is treated as a set
of objects to treat as recent, regardless of their true age.
The implementation is straightforward. Git enumerates recent objects via
`add_unseen_recent_objects_to_traversal()`, which enumerates loose and
packed objects, and eventually calls add_recent_object() on any objects
for which `want_recent_object()`'s conditions are met.
This patch modifies the recency condition from simply "is the mtime of
this object more recent than the cutoff?" to "[...] or, is this object
mentioned by at least one `gc.recentObjectsHook`?".
Depending on whether or not we are generating a cruft pack, this allows
the caller to do one of two things:
- If generating a cruft pack, the caller is able to retain additional
objects via the cruft pack, even if they would have otherwise been
pruned due to their age.
- If not generating a cruft pack, the caller is likewise able to
retain additional objects as loose.
A potential alternative here is to introduce a new mode to alter the
contents of the reachable pack instead of the cruft one. One could
imagine a new option to `pack-objects`, say `--extra-reachable-tips`
that does the same thing as above, adding the visited set of objects
along the traversal to the pack.
But this has the unfortunate side-effect of altering the reachability
closure of that pack. If parts of the unreachable object graph mentioned
by one or more of the "extra reachable tips" programs is not closed,
then the resulting pack won't be either. This makes it impossible in the
general case to write out reachability bitmaps for that pack, since
closure is a requirement there.
Instead, keep these unreachable objects in the cruft pack (or set of
unreachable, loose objects) instead, to ensure that we can continue to
have a pack containing just reachable objects, which is always safe to
write a bitmap over.
Helped-by: Jeff King <peff@peff.net> Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Wed, 7 Jun 2023 22:58:12 +0000 (18:58 -0400)]
reachable.c: extract `obj_is_recent()`
When enumerating objects in order to add recent ones (i.e. those whose
mtime is strictly newer than the cutoff) as tips of a reachability
traversal, `add_recent_object()` discards objects which do not meet the
recency criteria.
The subsequent commit will make checking whether or not an object is
recent also consult the list of hooks in `pack.recentHook`. Isolate this
check in its own function to keep the additional complexity outside of
`add_recent_object()`.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Junio C Hamano [Tue, 2 May 2023 17:13:35 +0000 (10:13 -0700)]
Merge branch 'tb/ban-strtok'
Mark strtok() and strtok_r() to be banned.
* tb/ban-strtok:
banned.h: mark `strtok()` and `strtok_r()` as banned
t/helper/test-json-writer.c: avoid using `strtok()`
t/helper/test-oidmap.c: avoid using `strtok()`
t/helper/test-hashmap.c: avoid using `strtok()`
string-list: introduce `string_list_setlen()`
string-list: multi-delimiter `string_list_split_in_place()`
Junio C Hamano [Tue, 2 May 2023 17:13:34 +0000 (10:13 -0700)]
Merge branch 'jk/blame-fake-commit-label'
The output given by "git blame" that attributes a line to contents
taken from the file specified by the "--contents" option shows it
differently from a line attributed to the working tree file.
* jk/blame-fake-commit-label:
blame: use different author name for fake commit generated by --contents
The completion script used to use bare "read" without the "-r"
option to read the contents of various state files, which risked
getting confused with backslashes in them. This has been
corrected.
* ek/completion-use-read-r-to-read-literally:
completion: suppress unwanted unescaping of `read`
Junio C Hamano [Fri, 28 Apr 2023 23:03:03 +0000 (16:03 -0700)]
Merge branch 'jk/gpg-trust-level-fix'
The "%GT" placeholder for the "--format" option of "git log" and
friends caused BUG() to trigger on a commit signed with an unknown
key, which has been corrected.
* jk/gpg-trust-level-fix:
gpg-interface: set trust level of missing key to "undefined"
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()
Taylor Blau [Mon, 24 Apr 2023 22:20:26 +0000 (18:20 -0400)]
banned.h: mark `strtok()` and `strtok_r()` as banned
`strtok()` has a couple of drawbacks that make it undesirable to have
any new instances. In addition to being thread-unsafe, it also
encourages confusing data flows, where `strtok()` may be called from
multiple functions with its first argument as NULL, making it unclear
from the immediate context which string is being tokenized.
Now that we have removed all instances of `strtok()` from the tree,
let's ban `strtok()` to avoid introducing new ones in the future. If new
callers should arise, they are encouraged to use
`string_list_split_in_place()` (and `string_list_remove_empty_items()`,
if applicable).
string_list_split_in_place() is not a perfect drop-in replacement
for `strtok_r()`, particularly if the caller is processing a string with
an arbitrary number of tokens, and wants to process each token one at a
time.
But there are no instances of this in Git's tree which are more
well-suited to `strtok_r()` than the friendlier
`string_list_split_in_place()`, so ban `strtok_r()`, too.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
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
...
Taylor Blau [Mon, 24 Apr 2023 22:20:23 +0000 (18:20 -0400)]
t/helper/test-json-writer.c: avoid using `strtok()`
Apply similar treatment as in the previous commit to remove usage of
`strtok()` from the "oidmap" test helper.
Each of the different commands that the "json-writer" helper accepts
pops the next space-delimited token from the current line and interprets
it as a string, integer, or double (with the exception of the very first
token, which is the command itself).
To accommodate this, split the line in place by the space character, and
pass the corresponding string_list to each of the specialized `get_s()`,
`get_i()`, and `get_d()` functions.
`get_i()` and `get_d()` are thin wrappers around `get_s()` that convert
their result into the appropriate type by either calling `strtol()` or
`strtod()`, respectively. In `get_s()`, we mark the token as "consumed"
by incrementing the `consumed_nr` counter, indicating how many tokens we
have read up to that point.
Because each of these functions needs the string-list parts, the number
of tokens consumed, and the line number, these three are wrapped up in
to a struct representing the line state.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Taylor Blau [Mon, 24 Apr 2023 22:20:17 +0000 (18:20 -0400)]
t/helper/test-hashmap.c: avoid using `strtok()`
Avoid using the non-reentrant `strtok()` to separate the parts of each
incoming command. Instead of replacing it with `strtok_r()`, let's
instead use the more friendly pair of `string_list_split_in_place()` and
`string_list_remove_empty_items()`.
Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
is preferable over calling `string_list_clear()` on every iteration of
the loop. This is because `string_list_clear()` causes us free our
existing `items` array. This means that every time we call
`string_list_split_in_place()`, the string-list internals re-allocate
the same size array.
Since in the above example we do not care about the individual parts
after processing each line, it is much more efficient to pretend that
there aren't any elements in the `string_list` by setting `list->nr` to
0 while leaving the list of elements allocated as-is.
This allows `string_list_split_in_place()` to overwrite any existing
entries without needing to free and re-allocate them.
However, setting `list->nr` manually is not safe in all instances. There
are a couple of cases worth worrying about:
- If the `string_list` is initialized with `strdup_strings`,
truncating the list can lead to overwriting strings which are
allocated elsewhere. If there aren't any other pointers to those
strings other than the ones inside of the `items` array, they will
become unreachable and leak.
(We could ourselves free the truncated items between
string_list->items[nr] and `list->nr`, but no present or future
callers would benefit from this additional complexity).
- If the given `nr` is larger than the current value of `list->nr`,
we'll trick the `string_list` into a state where it thinks there are
more items allocated than there actually are, which can lead to
undefined behavior if we try to read or write those entries.
Guard against both of these by introducing a helper function which
guards assignment of `list->nr` against each of the above conditions.
Co-authored-by: Jeff King <peff@peff.net> 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>
Enhance `string_list_split_in_place()` to accept multiple characters as
delimiters instead of a single character.
Instead of using `strchr(2)` to locate the first occurrence of the given
delimiter character, `string_list_split_in_place_multi()` uses
`strcspn(2)` to move past the initial segment of characters comprised of
any characters in the delimiting set.
When only a single delimiting character is provided, `strpbrk(2)` (which
is implemented with `strcspn(2)`) has equivalent performance to
`strchr(2)`. Modern `strcspn(2)` implementations treat an empty
delimiter or the singleton delimiter as a special case and fall back to
calling strchrnul(). Both glibc[1] and musl[2] implement `strcspn(2)`
this way.
This change is one step to removing `strtok(2)` from the tree. Note that
`string_list_split_in_place()` is not a strict replacement for
`strtok()`, since it will happily turn sequential delimiter characters
into empty entries in the resulting string_list. For example:
Jacob Keller [Mon, 24 Apr 2023 19:35:08 +0000 (12:35 -0700)]
blame: use different author name for fake commit generated by --contents
When the --contents option is used with git blame, and the contents of
the file have lines which can't be annotated by the history being
blamed, the user will see an author of "Not Committed Yet". This is
similar to the way blame handles working tree contents when blaming
without a revision.
This is slightly confusing since this data isn't the working copy and
while it is technically "not committed yet", its also coming from an
external file. Replace this author name with "External file
(--contents)" to better differentiate such lines from actual working
copy lines.
Suggested-by: Junio C Hamano <gitster@pobox.com> Suggested-by: Glen Choo <chooglen@google.com> Signed-off-by: Jacob Keller <jacob.keller@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
merge-ort: fix calling merge_finalize() with no intermediate merge
If some code sets up the data structures for a merge, but then never
actually performs one before calling merge_finalize(), then
merge_finalize() wouldn't notice that result->priv was NULL and
return early, resulting in following that NULL pointer and getting
a segfault. There is currently no code in the git codebase that does
this, but this issue was found during testing of some proposed patches
that had the following structure:
where some flags could cause the code to have N=0, i.e. doing no merges.
Add a check for result->priv being NULL and return early to avoid a
segfault in these kinds of cases.
While at it, ensure the FREE_AND_NULL() in the function does something
useful with the nulling aspect, namely sets result->priv to NULL rather
than a mere temporary.
Reported-by: Derrick Stolee <derrickstolee@github.com> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Sat, 22 Apr 2023 13:56:46 +0000 (09:56 -0400)]
fetch_bundle_uri(): drop pointless NULL check
We check if "uri" is NULL, but it cannot be since we'd have segfaulted
earlier in the function when we unconditionally called xstrdup() on it.
In theory we might want to soften that xstrdup() to handle this case,
but even before the code which added it via c23f592117 (bundle-uri:
fetch a list of bundles, 2022-10-12), we'd have fed NULL to
fetch_bundle_uri_internal(), which would also segfault.
The extra check isn't hurting anything, but it does cause Coverity to
complain, and it may mislead somebody reading the code into thinking
that a NULL uri is something we're prepared to handle.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King [Sat, 22 Apr 2023 13:55:43 +0000 (09:55 -0400)]
notes: clean up confusing NULL checks in init_notes()
Coverity complains that we check whether "notes_ref" is NULL, but it was
already implied to be non-NULL earlier in the function. And this is
true; since b9342b3fd63 (refs: add array of ref namespaces, 2022-08-05),
we call xstrdup(notes_ref) unconditionally, which would segfault if it
was NULL.
But that commit is actually doing the right thing. Even if NULL is
passed into the function, we'll use default_notes_ref() as a fallback,
which will never return NULL (it tries a few options, but its last
resort is a string literal). Ironically, the "!notes_ref" check was
added by the same commit that added the fallback: 709f79b0894 (Notes
API: init_notes(): Initialize the notes tree from the given notes ref,
2010-02-13). So this check never did anything.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
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.
completion: suppress unwanted unescaping of `read`
The function `__git_eread`, which reads the first line from the file,
calls the `read` builtin without passing the flag option `-r`. When
the `read` builtin is called without the flag `-r`, it processes the
backslash escaping in the text that it reads. For this reason, it is
generally considered the best practice to always use the `read`
builtin with flag `-r` unless one intensionally processes the
backslash escaping. For the present case in git-prompt.sh, in fact,
all the occurrences of the calls of `__git_eread` intend to read the
literal content of the first lines.
To make it read the first line literally, pass the flag `-r` to the
`read` builtin in the function `__git_eread`.
Signed-off-by: Edwin Kofler <edwin@kofler.dev> Signed-off-by: Koichi Murase <myoga.murase@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
"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
Jeff King [Wed, 19 Apr 2023 01:29:57 +0000 (21:29 -0400)]
gpg-interface: set trust level of missing key to "undefined"
In check_signature(), we initialize the trust_level field to "-1", with
the idea that if gpg does not return a trust level at all (if there is
no signature, or if the signature is made by an unknown key), we'll
use that value. But this has two problems:
1. Since the field is an enum, it's up to the compiler to decide what
underlying storage to use, and it only has to fit the values we've
declared. So we may not be able to store "-1" at all. And indeed,
on my system (linux with gcc), the resulting enum is an unsigned
32-bit value, and -1 becomes 4294967295.
The difference may seem academic (and you even get "-1" if you pass
it to printf("%d")), but it means that code like this:
status |= sigc->trust_level < configured_min_trust_level;
does not necessarily behave as expected. This turns out not to be a
bug in practice, though, because we keep the "-1" only when gpg did
not report a signature from a known key, in which case the line
above:
status |= sigc->result != 'G';
would always set status to non-zero anyway. So only a 'G' signature
with no parsed trust level would cause a problem, which doesn't
seem likely to trigger (outside of unexpected gpg behavior).
2. When using the "%GT" format placeholder, we pass the value to
gpg_trust_level_to_str(), which complains that the value is out of
range with a BUG(). This behavior was introduced by 803978da49
(gpg-interface: add function for converting trust level to string,
2022-07-11). Before that, we just did a switch() on the enum, and
anything that wasn't matched would end up as the empty string.
Curiously, solving this by naively doing:
if (level < 0)
return "";
in that function isn't sufficient. Because of (1) above, the
compiler can (and does in my case) actually remove that conditional
as dead code!
We can solve both by representing this state as an enum value. We could
do this by adding a new "unknown" value. But this really seems to match
the existing "undefined" level well. GPG describes this as "Not enough
information for calculation".
We have tests in t7510 that trigger this case (verifying a signature
from a key that we don't have, and then checking various %G
placeholders), but they didn't notice the BUG() because we didn't look
at %GT for that case! Let's make sure we check all %G placeholders for
each case in the formatting tests.
The interesting ones here are "show unknown signature with custom
format" and "show lack of signature with custom format", both of which
would BUG() before, and now turn %GT into "undefined". Prior to 803978da49 they would have turned it into the empty string, but I think
saying "undefined" consistently is a reasonable outcome, and probably
makes life easier for anyone parsing the output (and any such parser had
to be ready to see "undefined" already).
The other modified tests produce the same output before and after this
patch, but now we're consistently checking both %G? and %GT in all of
them.
Signed-off-by: Jeff King <peff@peff.net> Reported-by: Rolf Eike Beer <eb@emlix.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
projects / thirdparty / git.git / log
