We recently added tips for server admins to configure various transports
to support v2's GIT_PROTOCOL variable. While the protocol-v2 document is
pretty technical and not of interest to most admins, it may be a
starting point for them to figure out how to turn on v2. Let's put some
pointers from there to the other documentation.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The v2 protocol requires that the GIT_PROTOCOL environment variable gets
passed around, but we don't have any documentation describing how this
is supposed to work. In particular, we need to note what server admins
might need to configure to make things work.
The definition of the GIT_PROTOCOL variable is probably the best place
for this, since:
- we deal with multiple transports (ssh, http, etc).
Transport-specific documentation (like the git-http-backend bits
added in the previous commit) are helpful for those transports, but
this gives a broader overview. Plus we do not have a specific
transport endpoint program for ssh, so this is a reasonable place to
mention it.
- the server side of the protocol involves multiple programs. For now,
upload-pack is the only endpoint which uses GIT_PROTOCOL, but that
will likely expand in the future. We're better off with a central
discussion of what the server admin might need to do. However, for
discoverability, this patch adds a pointer from upload-pack's
documentation.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Historically there was a little bit of configuration needed at the
webserver level in order to get the client's v2 protocol probes to Git.
But when we introduced the v2 protocol, we never documented these.
As of the previous commit, this should mostly work out of the box
without any explicit configuration. But it's worth documenting this to
make it clear how we expect it to work, especially in the face of
webservers which don't provide all headers over the CGI interface. Or
anybody who runs across this documentation but has an older version of
Git (or _used_ to have an older version, and wonders why they still have
a SetEnvIf line in their Apache config and whether it's still
necessary).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a client requests the v2 protocol over HTTP, they set the
Git-Protocol header. Webservers will generally make that available to
our CGI as HTTP_GIT_PROTOCOL in the environment. However, that's not
sufficient for upload-pack, etc, to respect it; they look in
GIT_PROTOCOL (without the HTTP_ prefix).
Either the webserver or the CGI is responsible for relaying that HTTP
header into the GIT_PROTOCOL variable. Traditionally, our tests have
configured the webserver to do so, but that's a burden on the server
admin. We can make this work out of the box by having the http-backend
CGI copy the contents of HTTP_GIT_PROTOCOL to GIT_PROTOCOL.
There are no new tests here. By removing the SetEnvIf line from our
test Apache config, we're now relying on this behavior of http-backend
to trigger the v2 protocol there (and there are numerous tests that fail
if this doesn't work).
There is one subtlety here: we copy HTTP_GIT_PROTOCOL only if there is
no existing GIT_PROTOCOL variable. That leaves the webserver admin free
to override the client's decision if they choose. This is unlikely to be
useful in practice, but is more flexible. And indeed, it allows the
v2-to-v0 fallback test added in the previous commit to continue working.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since we use the v2 protocol by default, the connection of a v2 client
to a v2 server is well covered by the test suite. And with the
GIT_TEST_PROTOCOL_VERSION knob, we can easily test a v0 client
connecting to a v2-aware server (which will then just speak v0). But we
have no regular tests that a v2 client, when encountering a non-v2-aware
server, will correctly fall back to using v0.
In theory this is a job for the cross-version tests in t/interop, but:
- they cover only git:// and file:// clones
- they are not part of the usual test suite, so nobody ever runs them
anyway
Since using v2 over http requires configuring the web server to pass
along the Git-Protocol header, we can easily create a situation where
the server does not respect the v2 probe, and the conversation falls
back to v0.
This works just fine. This new test is not about fixing any particular
bug, but just making sure that the system works (and continues to work)
as expected.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Codepath to access recently added oidtree data structure had
to make unaligned accesses to oids, which has been corrected.
* rs/oidtree-alignment-fix:
oidtree: avoid unaligned access to crit-bit tree
Also fixed some typos reported by "git-po-helper".
Signed-off-by: Peter Krefting <peter@softwolves.pp.se>
Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
The flexible array member "k" of struct cb_node is used to store the key
of the crit-bit tree node. It offers no alignment guarantees -- in fact
the current struct layout puts it one byte after a 4-byte aligned
address, i.e. guaranteed to be misaligned.
oidtree uses a struct object_id as cb_node key. Since cf0983213c (hash:
add an algo member to struct object_id, 2021-04-26) it requires 4-byte
alignment. The mismatch is reported by UndefinedBehaviorSanitizer at
runtime like this:
hash.h:277:2: runtime error: member access within misaligned address 0x00015000802d for type 'struct object_id', which requires 4 byte alignment
0x00015000802d: note: pointer points here
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^
SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior hash.h:277:2 in
We can fix that by:
1. eliminating the alignment requirement of struct object_id,
2. providing the alignment in struct cb_node, or
3. avoiding the issue by only using memcpy to access "k".
Currently we only store one of two values in "algo" in struct object_id.
We could use a uint8_t for that instead and widen it only once we add
support for our twohundredth algorithm or so. That would not only avoid
alignment issues, but also reduce the memory requirements for each
instance of struct object_id by ca. 9%.
Supporting keys with alignment requirements might be useful to spread
the use of crit-bit trees. It can be achieved by using a wider type for
"k" (e.g. uintmax_t), using different types for the members "byte" and
"otherbits" (e.g. uint16_t or uint32_t for each), or by avoiding the use
of flexible arrays like khash.h does.
This patch implements the third option, though, because it has the least
potential for causing side-effects and we're close to the next release.
If one of the other options is implemented later as well to get their
additional benefits we can get rid of the extra copies introduced here.
Reported-by: Andrzej Hunt <andrzej@ahunt.org>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Translate 48 new messages (5230t0f0u) for git 2.33.0, and also fixed
typos found by "git-po-helper".
Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Fangyi Zhou <me@fangyi.io>
Format README.md using GFM (GitHub Flavored Markdown) syntax.
- In order to use more than 3 level headings, use ATX style headings
instead of setext style headings.
- In order to add highlights for code blocks, use fenced code blocks
instead of indented code blocks.
Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Update translation for following component:
* builtin/submodule--helper.c
Translate following new component:
* builtin/revert.c
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
* 'master' of github.com:git/git: (51 commits)
Git 2.33-rc2
object-file: use unsigned arithmetic with bit mask
Revert 'diff-merges: let "-m" imply "-p"'
object-store: avoid extra ';' from KHASH_INIT
oidtree: avoid nested struct oidtree_node
Git 2.33-rc1
test: fix for COLUMNS and bash 5
The eighth batch
diff: --pickaxe-all typofix
mingw: align symlinks-related rmdir() behavior with Linux
t7508: avoid non POSIX BRE
use fspathhash() everywhere
t0001: fix broken not-quite getcwd(3) test in bed67874e2
Documentation: render special characters correctly
reset: clear_unpack_trees_porcelain to plug leak
builtin/rebase: fix options.strategy memory lifecycle
builtin/merge: free found_ref when done
builtin/mv: free or UNLEAK multiple pointers at end of cmd_mv
convert: release strbuf to avoid leak
read-cache: call diff_setup_done to avoid leak
...
Jiang Xin reported possible typos in po/id.po, all of them are mismatch
variable names. Fix them.
Reported-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Earlier "git log -m" was changed to always produce patch output,
which would break existing scripts, which has been reverted.
* jn/log-m-does-not-imply-p:
Revert 'diff-merges: let "-m" imply "-p"'
Build fix.
* cb/many-alternate-optim-fixup:
object-file: use unsigned arithmetic with bit mask
object-store: avoid extra ';' from KHASH_INIT
oidtree: avoid nested struct oidtree_node
33f379eee6 (make object_directory.loose_objects_subdir_seen a bitmap,
2021-07-07) replaced a wasteful 256-byte array with a 32-byte array
and bit operations. The mask calculation shifts a literal 1 of type
int left by anything between 0 and 31. UndefinedBehaviorSanitizer
doesn't like that and reports:
object-file.c:2477:18: runtime error: left shift of 1 by 31 places cannot be represented in type 'int'
Make sure to use an unsigned 1 instead to avoid the issue.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
