The dumb-http code regressed when the result of re-indexing a pack
yielded an *.idx file that differs in content from the *.idx file it
downloaded from the remote. This has been corrected by no longer
relying on the *.idx file we got from the remote.
* jk/dumb-http-finalize:
packfile: use oidread() instead of hashcpy() to fill object_id
packfile: use object_id in find_pack_entry_one()
packfile: convert find_sha1_pack() to use object_id
http-walker: use object_id instead of bare hash
packfile: warn people away from parse_packed_git()
packfile: drop sha1_pack_index_name()
packfile: drop sha1_pack_name()
packfile: drop has_pack_index()
dumb-http: store downloaded pack idx as tempfile
t5550: count fetches in "previously-fetched .idx" test
midx: avoid duplicate packed_git entries
Replace various calls to atoi() with strtol_i() and strtoul_ui(), and
add improved error handling.
* ua/atoi:
imap: replace atoi() with strtol_i() for UIDVALIDITY and UIDNEXT parsing
merge: replace atoi() with strtol_i() for marker size validation
daemon: replace atoi() with strtoul_ui() and strtol_i()
Teach 'git notes add' and 'git notes append' a new '-e' flag,
instructing them to open the note in $GIT_EDITOR before saving.
* sa/notes-edit:
notes: teach the -e option to edit messages in editor
Documentation update to clarify that 'uploadpack.allowAnySHA1InWant'
implies both 'allowTipSHA1InWant' and 'allowReachableSHA1InWant'.
* ps/upload-pack-doc:
doc: document how uploadpack.allowAnySHA1InWant impact other allow options
Treat ECONNABORTED the same as ECONNRESET in 'git credential-cache' to
work around a possible Cygwin regression. This resolves a race condition
caused by changes in Cygwin's handling of socket closures, allowing the
client to exit cleanly when encountering ECONNABORTED.
* rj/cygwin-exit:
credential-cache: treat ECONNABORTED like ECONNRESET
Test update.
* ua/t3404-cleanup:
t3404: replace test with test_line_count()
t3404: avoid losing exit status with focus on `git show` and `git cat-file`
Various platform compatibility fixes split out of the larger effort
to use Meson as the primary build tool.
* ps/platform-compat-fixes:
t6006: fix prereq handling with `test_format ()`
http: fix build error on FreeBSD
builtin/credential-cache: fix missing parameter for stub function
t7300: work around platform-specific behaviour with long paths on MinGW
t5500, t5601: skip tests which exercise paths with '[::1]' on Cygwin
t3404: work around platform-specific behaviour on macOS 10.15
t1401: make invocation of tar(1) work with Win32-provided one
t/lib-gpg: fix setup of GNUPGHOME in MinGW
t/lib-gitweb: test against the build version of gitweb
t/test-lib: wire up NO_ICONV prerequisite
t/test-lib: fix quoting of TEST_RESULTS_SAN_FILE
Avoid losing exit status by having Git command being tested on the
upstream side of a pipe.
* co/t6050-pipefix:
t6050: avoid pipes with upstream Git commands
Teaches the ref-filter machinery to recognize and avoid cases where
sorting would be redundant.
* ps/ref-filter-sort:
ref-filter: format iteratively with lexicographic refname sorting
Implements a new reftable-specific strbuf replacement to reduce
reftable's dependency on Git-specific data structures.
* ps/reftable-strbuf:
reftable: handle trivial `reftable_buf` errors
reftable/stack: adapt `stack_filename()` to handle allocation failures
reftable/record: adapt `reftable_record_key()` to handle allocation failures
reftable/stack: adapt `format_name()` to handle allocation failures
t/unit-tests: check for `reftable_buf` allocation errors
reftable/blocksource: adapt interface name
reftable: convert from `strbuf` to `reftable_buf`
reftable/basics: provide new `reftable_buf` interface
reftable: stop using `strbuf_addf()`
reftable: stop using `strbuf_addbuf()`
In df383b5842 (t/test-lib: wire up NO_ICONV prerequisite, 2024-10-16) we
have introduced a new NO_ICONV prerequisite that makes us skip tests in
case Git is not compiled with support for iconv. This change subtly
broke t6006: while the test suite still passes, some of its tests won't
execute because they run into an error.
./t6006-rev-list-format.sh: line 92: test_expect_%e: command not found
The broken tests use `test_format ()`, and the mentioned commit simply
prepended the new prerequisite to its arguments. But that does not work,
as the function is not aware of prereqs at all and will now treat all of
its arguments incorrectly.
Fix this by making the function aware of prereqs by accepting an
optional fourth argument. Adapt the callsites accordingly.
Reported-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
When chasing a REF_DELTA, we need to pull the raw hash bytes out of the
mmap'd packfile into an object_id struct. We do that with a raw
hashcpy() of the appropriate length (that happens directly now, though
before the previous commit it happened inside find_pack_entry_one(),
also using a hashcpy).
But I think this creates a potentially dangerous situation due to
d4d364b2c7 (hash: convert `oidcmp()` and `oideq()` to compare whole
hash, 2024-06-14). When using sha1, we'll have uninitialized bytes in
the latter part of the object_id.hash buffer, which could fool oideq(),
etc.
We should use oidread() instead, which correctly zero-pads the extra
bytes, as of c98d762ed9 (global: ensure that object IDs are always
padded, 2024-06-14).
As far as I can see, this has not been a problem in practice because the
object_id we feed to find_pack_entry_one() is never used with oideq(),
etc. It is being compared to the bytes mmap'd from a pack idx file,
which of course do not have the extra padding bytes themselves. So
there's no bug here, but this just puzzled me while looking at the code.
We should do the more obviously safe thing, both for future-proofing and
to avoid confusing readers.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
The main function we use to search a pack index for an object is
find_pack_entry_one(). That function still takes a bare pointer to the
hash, despite the fact that its underlying bsearch_pack() function needs
an object_id struct. And so we end up making an extra copy of the hash
into the struct just to do a lookup.
As it turns out, all callers but one already have such an object_id. So
we can just take a pointer to that struct and use it directly. This
avoids the extra copy and provides a more type-safe interface.
The one exception is get_delta_base() in packfile.c, when we are chasing
a REF_DELTA from inside the pack (and thus we have a pointer directly to
the mmap'd pack memory, not a struct). We can just bump the hashcpy()
from inside find_pack_entry_one() to this one caller that needs it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
The find_sha1_pack() function has a few problems:
- it's badly named, since it works with any object hash
- it takes the hash as a bare pointer rather than an object_id struct
We can fix both of these easily, as all callers actually have a real
object_id anyway.
I also found the existence of this function somewhat confusing, as it is
about looking in an arbitrary set of linked packed_git structs. It's
good for things like dumb-http which are looking in downloaded remote
packs, and not our local packs. But despite the name, it is not a good
way to find the pack which contains a local object (it skips the use of
the midx, the pack mru list, and so on).
So let's also add an explanatory comment above the declaration that may
point people in the right direction.
I suspect the calls in fast-import.c, which use the packed_git list from
the repository struct, could actually just be using find_pack_entry().
But since we'd need to keep it anyway for dumb-http, I didn't dig
further there. If we eventually drop dumb-http support, then it might be
worth examining them to see if we can get rid of the function entirely.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
We long ago switched most code to using object_id structs instead of
bare "unsigned char *" hashes. This gives us more type safety from the
compiler, and generally makes it easier to understand what we expect in
each parameter.
But the dumb-http code has lagged behind. And indeed, the whole "walker"
subsystem interface has the same problem, though http-walker is the only
user left.
So let's update the walker interface to pass object_id structs (which we
already have anyway at all call sites!), and likewise use those within
the http-walker methods that it calls.
This cleans up the dumb-http code a bit, but will also let us fix a few
more commonly used helper functions.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
With a name like parse_packed_git(), you might think it's the right way
to access a local pack index and its associated objects. But not so!
It's a one-off used by the dumb-http code to access pack idx files we've
downloaded from the remote, but whose packs we might not have.
There's only one caller left for this function, and ideally we'd drop it
completely and just inline it there. But that would require exposing
other internals from packfile.[ch], like alloc_packed_git() and
check_packed_git_idx().
So let's leave it be for now, and just warn people that it's probably
not what they're looking for. Perhaps in the long run if we eventually
drop dumb-http support, we can remove the function entirely then.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Like sha1_pack_name() that we dropped in the previous commit, this
function uses an error-prone static strbuf and the somewhat misleading
name "sha1".
The only caller left is in pack-redundant.c. While this command is
marked for potential removal in our BreakingChanges document, we still
have it for now. But it's simple enough to convert it to use its own
strbuf with the underlying odb_pack_name() function, letting us drop the
otherwise obsolete function.
Note that odb_pack_name() does its own strbuf_reset(), so it's safe to
use directly within a loop like this.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
The sha1_pack_name() function has a few ugly bits:
- it writes into a static strbuf (and not even a ring buffer of them),
which can lead to subtle invalidation problems
- it uses the term "sha1", but it's really using the_hash_algo, which
could be sha256
There's only one caller of it left. And in fact that caller is better
off using the underlying odb_pack_name() function itself, since it's
just copying the result into its own strbuf anyway.
Converting that caller lets us get rid of this now-obselete function.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
The has_pack_index() function has several oddities that may make it
surprising if you are trying to find out if we have a pack with some
$hash:
- it is not looking for a valid pack that we found while searching
object directories. It just looks for any pack-$hash.idx file in the
pack directory.
- it only looks in the local directory, not any alternates
- it takes a bare "unsigned char" hash, which we try to avoid these
days
The only caller it has is in the dumb http code; it wants to know if we
already have the pack idx in question. This can happen if we downloaded
the pack (and generated its index) during a previous fetch.
Before the previous patch ("dumb-http: store downloaded pack idx as
tempfile"), it could also happen if we downloaded the .idx from the
remote but didn't get the matching .pack. But since that patch, we don't
hold on to those .idx files. So there's no need to look for the .idx
file in the filesystem; we can just scan through the packed_git list to
see if we have it.
That lets us simplify the dumb http code a bit, as we know that if we
have the .idx we have the matching .pack already. And it lets us get rid
of this odd function that is unlikely to be needed again.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
This patch fixes a regression in b1b8dfde69 (finalize_object_file():
implement collision check, 2024-09-26) where fetching a v1 pack idx file
over the dumb-http protocol would cause the fetch to fail.
The core of the issue is that dumb-http stores the idx we fetch from the
remote at the same path that will eventually hold the idx we generate
from "index-pack --stdin". The sequence is something like this:
0. We realize we need some object X, which we don't have locally, and
nor does the other side have it as a loose object.
1. We download the list of remote packs from objects/info/packs.
2. For each entry in that file, we download each pack index and store
it locally in .git/objects/pack/pack-$hash.idx (the $hash is not
something we can verify yet and is given to us by the remote).
3. We check each pack index we got to see if it has object X. When we
find a match, we download the matching .pack file from the remote
to a tempfile. We feed that to "index-pack --stdin", which
reindexes the pack, rather than trusting that it has what the other
side claims it does. In most cases, this will end up generating the
exact same (byte-for-byte) pack index which we'll store at the same
pack-$hash.idx path, because the index generation and $hash id are
computed based on what's in the packfile. But:
a. The other side might have used other options to generate the
index. For instance we use index v2 by default, but long ago
it was v1 (and you can still ask for v1 explicitly).
b. The other side might even use a different mechanism to
determine $hash. E.g., long ago it was based on the sorted
list of objects in the packfile, but we switched to using the
pack checksum in 1190a1acf8 (pack-objects: name pack files
after trailer hash, 2013-12-05).
The regression we saw in the real world was (3a). A recent client
fetching from a server with a v1 index downloaded that index, then
complained about trying to overwrite it with its own v2 index. This
collision is otherwise harmless; we know we want to replace the remote
version with our local one, but the collision check doesn't realize
that.
There are a few options to fix it:
- we could teach index-pack a command-line option to ignore only pack
idx collisions, and use it when the dumb-http code invokes
index-pack. This would be an awkward thing to expose users to and
would involve a lot of boilerplate to get the option down to the
collision code.
- we could delete the remote .idx file right before running
index-pack. It should be redundant at that point (since we've just
downloaded the matching pack). But it feels risky to delete
something from our own .git/objects based on what the other side has
said. I'm not entirely positive that a malicious server couldn't lie
about which pack-$hash.idx it has and get us to delete something
precious.
- we can stop co-mingling the downloaded idx files in our local
objects directory. This is a slightly bigger change but I think
fixes the root of the problem more directly.
This patch implements the third option. The big design questions are:
where do we store the downloaded files, and how do we manage their
lifetimes?
There are some additional quirks to the dumb-http system we should
consider. Remember that in step 2 we downloaded every pack index, but in
step 3 we may only download some of the matching packs. What happens to
those other idx files now? They sit in the .git/objects/pack directory,
possibly waiting to be used at a later date. That may save bandwidth for
a subsequent fetch, but it also creates a lot of weird corner cases:
- our local object directory now has semi-untrusted .idx files sitting
around, without their matching .pack
- in case 3b, we noted that we might not generate the same hash as the
other side. In that case even if we download the matching pack,
our index-pack invocation will store it in a different
pack-$hash.idx file. And the unmatched .idx will sit there forever.
- if the server repacks, it may delete the old packs. Now we have
these orphaned .idx files sitting around locally that will never be
used (nor deleted).
- if we repack locally we may delete our local version of the server's
pack index and not realize we have it. So we'll download it again,
even though we have all of the objects it mentions.
I think the right solution here is probably some more complex cache
management system: download the remote .idx files to their own storage
directory, mark them as "seen" when we get their matching pack (to avoid
re-downloading even if we repack), and then delete them when the
server's objects/info/refs no longer mentions them.
But since the dumb http protocol is so ancient and so inferior to the
smart http protocol, I don't think it's worth spending a lot of time
creating such a system. For this patch I'm just downloading the idx
files to .git/objects/tmp_pack_*, and marking them as tempfiles to be
deleted when we exit (and due to the name, any we miss due to a crash,
etc, should eventually be removed by "git gc" runs based on timestamps).
That is slightly worse for one case: if we download an idx but not the
matching pack, we won't retain that idx for subsequent runs. But the
flip side is that we're making other cases better (we never hold on to
useless idx files forever). I suspect that worse case does not even come
up often, since it implies that the packs are generated to match
distinct parts of history (i.e., in practice even in a repo with many
packs you're going to end up grabbing all of those packs to do a clone).
If somebody really cares about that, I think the right path forward is a
managed cache directory as above, and this patch is providing the first
step in that direction anyway (by moving things out of the objects/pack/
directory).
There are two test changes. One demonstrates the broken v1 index case
(it double-checks the resulting clone with fsck to be careful, but prior
to this patch it actually fails at the clone step). The other tweaks the
expectation for a test that covers the "slightly worse" case to
accommodate the extra index download.
The code changes are fairly simple. We stop using finalize_object_file()
to copy the remote's index file into place, and leave it as a tempfile.
We give the tempfile a real ".idx" name, since the packfile code expects
that, and thus we make sure it is out of the usual packs/ directory (so
we'd never mistake it for a real local .idx).
We also have to change parse_pack_index(), which creates a temporary
packed_git to access our index (we need this because all of the pack idx
code assumes we have that struct). It reads the index data from the
tempfile, but prior to this patch would speculatively write the
finalized name into the packed_git struct using the pack-$hash we expect
to use.
I was mildly surprised that this worked at all, since we call
verify_pack_index() on the packed_git which mentions the final name
before moving the file into place! But it works because
parse_pack_index() leaves the mmap-ed data in the struct, so the
lazy-open in verify_pack_index() never triggers, and we read from the
tempfile, ignoring the filename in the struct completely. Hacky, but it
works.
After this patch, parse_pack_index() now uses the index filename we pass
in to derive a matching .pack name. This is OK to change because there
are only two callers, both in the dumb http code (and the other passes
in an existing pack-$hash.idx name, so the derived name is going to be
pack-$hash.pack, which is what we were using anyway).
I'll follow up with some more cleanups in that area, but this patch is
sufficient to fix the regression.
Reported-by: fox <fox.gbr@townlong-yak.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
We have a test in t5550 that looks at index fetching over dumb http. It
creates two branches, each of which is completely stored in its own
pack, then fetches the branches independently. What should (and does)
happen is that the first fetch grabs both .idx files and one .pack file,
and then the fetch of the second branch re-uses the previously
downloaded .idx files (fetching none) and grabs the now-required .pack
file.
Since the next few patches will be touching this area of the code, let's
beef up the test a little by checking that we're downloading the
expected items at each step.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
When we scan a pack directory to load the idx entries we find into the
packed_git list, we skip any of them that are contained in a midx. We
then load them later lazily if we actually need to access the
corresponding pack, referencing them both from the midx struct and the
packed_git list.
The lazy-load in the midx code checks to see if the midx already
mentions the pack, but doesn't otherwise check the packed_git list. This
makes sense, since we should have added any pack to both lists.
But there's a loophole! If we call close_object_store(), that frees the
midx entirely, but _not_ the packed_git structs, which we must keep
around for Reasons[1]. If we then try to look up more objects, we'll
auto-load the midx again, which won't realize that we've already loaded
those packs, and will create duplicate entries in the packed_git list.
This is possibly inefficient, because it means we may open and map the
pack redundantly. But it can also lead to weird user-visible behavior.
The case I found is in "git repack", which closes and reopens the midx
after repacking and then calls update_server_info(). We end up writing
the duplicate entries into objects/info/packs.
We could obviously de-dup them while writing that file, but it seems
like a violation of more core assumptions that we end up with these
duplicate structs at all.
We can avoid the duplicates reasonably efficiently by checking their
names in the pack_map hash. This annoyingly does require a little more
than a straight hash lookup due to the naming conventions, but it should
only happen when we are about to actually open a pack. I don't think one
extra malloc will be noticeable there.
[1] I'm not entirely sure of all the details, except that we generally
assume the packed_git structs never go away. We noted this
restriction in the comment added by 6f1e9394e2 (object: fix leaking
packfiles when closing object store, 2024-08-08), but it's somewhat
vague. At any rate, if you try freeing the structs in
close_object_store(), you can observe segfaults all over the test
suite. So it might be fixable, but it's not trivial.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Teaches 'shortlog' to explicitly use SHA-1 when operating outside of
a repository.
* wm/shortlog-hash:
builtin/shortlog: explicitly set hash algo when there is no repo
Commands that can also work outside Git have learned to take the
repository instance "repo" when we know we are in a repository, and
NULL when we are not, in a parameter. The uses of the_repository
variable in a few of them have been removed using the new calling
convention.
* jc/a-commands-without-the-repo:
archive: remove the_repository global variable
annotate: remove usage of the_repository global
git: pass in repo to builtin based on setup_git_directory_gently
Enable Windows-based CI in GitLab.
* ps/ci-gitlab-windows:
gitlab-ci: exercise Git on Windows
gitlab-ci: introduce stages and dependencies
ci: handle Windows-based CI jobs in GitLab CI
ci: create script to set up Git for Windows SDK
t7300: work around platform-specific behaviour with long paths on MinGW
A "git fetch" from the superproject going down to a submodule used
a wrong remote when the default remote names are set differently
between them.
* db/submodule-fetch-with-remote-name-fix:
submodule: correct remote name with fetch
Replace unsafe uses of atoi() with strtol_i() to improve error handling
when parsing UIDVALIDITY, UIDNEXT, and APPENDUID in IMAP commands.
Invalid values, such as those with letters, now trigger error messages and
prevent malformed status responses.
I did not add any test for this commit as we do not have any test
for git-imap-send(1) at this point.
Signed-off-by: Usman Akinyemi <usmanakinyemi202@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Replace atoi() with strtol_i() for parsing conflict-marker-size to
improve error handling. Invalid values, such as those containing letters
now trigger a clear error message.
Update the test to verify invalid input handling.
Signed-off-by: Usman Akinyemi <usmanakinyemi202@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Replace atoi() with strtoul_ui() for --timeout and --init-timeout
(non-negative integers) and with strtol_i() for --max-connections
(signed integers). This improves error handling and input validation
by detecting invalid values and providing clear error messages.
Update tests to ensure these arguments are properly validated.
Signed-off-by: Usman Akinyemi <usmanakinyemi202@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Fix typos and grammar in documentation, comments, etc.
Via codespell.
Reported-by: Kristoffer Haugsbakk <kristofferhaugsbakk@fastmail.com>
Signed-off-by: Andrew Kreimer <algonell@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
`git mv a/a.txt a b/` is a nonsense instruction. Instead of failing
gracefully the command trips over itself,[1] leaving behind unfinished
work:
1. first it moves `a/a.txt` to `b/a.txt`; then
2. tries to move `a/`, including `a/a.txt`; then
3. figures out that it’s in a bad state (assertion); and finally
4. aborts.
Now you’re left with a partially-updated index.
The command should instead fail gracefully and make no changes to the
index until it knows that it can complete a sensible action.
For now just add a failing test since this has been known about for
a while.[2]
† 1: Caused by a `pos >= 0` assertion
[2]: https://lore.kernel.org/git/d1f739fe-b28e-451f-9e01-3d2e24a0fe0d@app.fastmail.com/
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
