Make the usage string consistent with Git.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Follow the conventional Python style by using 4-space indents
instead of hard tabs.
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The 'sys' module is not imported but all of the bits
we want from it are. Adjust the script to not fail
when run on old Python versions and fix the inconsistent
use of tabs.
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the usage string consistent with Git.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the usage string consistent with Git.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the usage string consistent with Git.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the usage string consistent with Git.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the usage string consistent with Git.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the usage string consistent with Git.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the usage string consistent with Git.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the usage string consistent with Git.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the usage string consistent with Git.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mergetool, bisect, and other commands that use
git-sh-setup print a usage string that is inconsistent
with the rest of Git when they are invoked as "git $cmd -h".
The compiled builtins use the lowercase "usage:" string
but these commands say "Usage:". Adjust the shell library
to make these consistent.
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When remote-curl receives a list of refs from a server, it
keeps the whole buffer intact. When we get a "list" command,
we feed the result to get_remote_heads, and when we get a
"fetch" or "push" command, we feed it to fetch-pack or
send-pack, respectively.
If the HTTP response from the server is truncated for any
reason, we will get an incomplete ref advertisement. If we
then feed this incomplete list to fetch-pack, one of a few
things may happen:
1. If the truncation is in a packet header, fetch-pack
will notice the bogus line and complain.
2. If the truncation is inside a packet, fetch-pack will
keep waiting for us to send the rest of the packet,
which we never will.
3. If the truncation is at a packet boundary, fetch-pack
will keep waiting for us to send the next packet, which
we never will.
As a result, fetch-pack hangs, waiting for input. However,
remote-curl believes it has sent all of the advertisement,
and therefore waits for fetch-pack to speak. The two
processes end up in a deadlock.
We do notice the broken ref list if we feed it to
get_remote_heads. So if git asks the helper to do a "list"
followed by a "fetch", we are safe; we'll abort during the
list operation, which parses the refs.
This patch teaches remote-curl to always parse and save the
incoming ref list when we read the ref advertisement from a
server. That means that we will always verify and abort
before even running fetch-pack (or send-pack) when reading a
corrupted list, even if we do not run the "list" command
explicitly.
Since we save the result, in the common case of running
"list" then "fetch", we do not do any extra parsing at all.
In the case of just a "fetch", we do an extra round of
parsing, but only once.
Note also that the "fetch" case will now also initialize
server_capabilities from the remote (in remote-curl; we
already would do so inside fetch-pack). Doing "list+fetch"
already does this. It doesn't actually matter now, but the
new behavior is arguably more correct, should remote-curl
ever start caring about the server's capability list.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The ref-parsing functions are static. Let's move them up in
the file to be available to more functions, which will help
us with later refactoring.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Until recently, get_remote_heads only knew how to read refs
from a file descriptor. To hack around this, we spawned a
thread (or forked a process) to write the buffer back to us.
Now that we can just pass it our buffer directly, we don't
have to use this hack anymore.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that we can read packet data from memory as easily as a
descriptor, get_remote_heads can take either one as a
source. This will allow further refactoring in remote-curl.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The packet_read function reads from a descriptor. The
packet_get_line function is similar, but reads from an
in-memory buffer, and uses a completely separate
implementation. This patch teaches the generic packet_read
function to accept either source, and we can do away with
packet_get_line's implementation.
There are two other differences to account for between the
old and new functions. The first is that we used to read
into a strbuf, but now read into a fixed size buffer. The
only two callers are fine with that, and in fact it
simplifies their code, since they can use the same
static-buffer interface as the rest of the packet_read_line
callers (and we provide a similar convenience wrapper for
reading from a buffer rather than a descriptor).
This is technically an externally-visible behavior change in
that we used to accept arbitrary sized packets up to 65532
bytes, and now cap out at LARGE_PACKET_MAX, 65520. In
practice this doesn't matter, as we use it only for parsing
smart-http headers (of which there is exactly one defined,
and it is small and fixed-size). And any extension headers
would be breaking the protocol to go over LARGE_PACKET_MAX
anyway.
The other difference is that packet_get_line would return
on error rather than dying. However, both callers of
packet_get_line are actually improved by dying.
The first caller does its own error checking, but we can
drop that; as a result, we'll actually get more specific
reporting about protocol breakage when packet_read dies
internally. The only downside is that packet_read will not
print the smart-http URL that failed, but that's not a big
deal; anybody not debugging can already see the remote's URL
already, and anybody debugging would want to run with
GIT_CURL_VERBOSE anyway to see way more information.
The second caller, which is just trying to skip past any
extra smart-http headers (of which there are none defined,
but which we allow to keep room for future expansion), did
not error check at all. As a result, it would treat an error
just like a flush packet. The resulting mess would generally
cause an error later in get_remote_heads, but now we get
error reporting much closer to the source of the problem.
Brown-paper-bag-fixes-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Descriptions borrowed from templates/hooks--pre-rebase.sample.
Signed-off-by: W. Trevor King <wking@tremily.us>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When considering a rename for two files that have a suffix and a prefix
that can overlap, a confusing line is shown. As an example, renaming
"a/b/b/c" to "a/b/c" shows "a/b/{ => }/b/c".
Currently, what we do is calculate the common prefix ("a/b/"), and the
common suffix ("/b/c"), but the same "/b/" is actually counted both in
prefix and suffix. Then when calculating the size of the non-common part,
we end-up with a negative value which is reset to 0, thus the "{ => }".
Do not allow the common suffix to overlap the common prefix and stop
when reaching a "/" that would be in both.
Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Even though "git update-index" was updated to use parse-options
infrastracture some time ago to make it possible to show list of
options with usage_with_options(), "git update-index -h" only shows
the usage. Detect this case and call usage_with_options() to show
the list of options as well.
Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
branch_get() can return NULL (so far on detached HEAD only) but some
code paths in builtin/branch.c cannot deal with that and cause
segfaults.
While at there, make sure to bail out when the user gives 2 or more
branches with --set-upstream-to or --unset-upstream, where only the
first branch is processed and the rest silently dropped.
Reported-by: Per Cederqvist <cederp@opera.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
'commit -s' populates the edit buffer with a blank line before the
Signed-off-by line, to allow the user to immediately start typing
the log message. But commit 33f2f9ab removed this space, forcing
the user to first push the Signed-off-by line down to open a place
to type the log message.
Fix this regression and let's ensure that the Signed-off-by line is
preceded by two blank lines, instead of just one, to hint that
something should be filled in, and that a blank line should separate
it from the body and the Signed-off-by line.
Add a test for this behavior.
Reported-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Brandon Casey <drafnel@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These tests call test_set_editor to set an alternate editor script, but
they appear to presume that the assignment is of a temporary nature and
will not have any effect outside of each individual test. That is not
the case. All of the test functions within a test script share a single
environment, so any variables modified in one, are visible in the ones
that follow.
So, let's protect the test functions that follow these, which set an
alternate editor, by performing the test_set_editor and 'git commit'
in a subshell.
Signed-off-by: Brandon Casey <drafnel@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It said "by default it is off" while it also said "the default is
always", which confused everybody who read it only once. It wanted
to say (1) if you do not say --color, it is not enabled, and (2) if
you say --color but do not say when to enable it, it will always be
enabled".
Rephrase to clarify by using "default" only once.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Read and write each 1024 byte buffer, rather than trying to buffer
the entire content of the file. We are only copying the contents to
a file descriptor and do not use it ourselves.
Previous code would crash on all files > 2 Gib, when the offset
variable became negative (perhaps below the level of perl),
resulting in a crash. On a 32 bit system, or a system with low
memory it might crash before reaching 2 GiB due to memory
exhaustion.
This code may leave a partial file behind in case of failure, where
the old code would leave a completely empty file. Neither version
verifies the correctness of the content. Calling code must take
care of verification and cleanup.
Signed-off-by: Joshua Clayton <stillcompiling@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
9d22778 (read-cache.c: write prefix-compressed names in the index -
2012-04-04) defined these. Interestingly, they were not used by
read-cache.c, or anywhere in that patch. They were used in
builtin/update-index.c later for checking supported index
versions. Use them here too.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 1b77d83cab 'setup_git_directory_gently_1(): resolve symlinks
in ceiling paths' changed the setup code to resolve symlinks in the
entries in GIT_CEILING_DIRECTORIES. Because those entries are
compared textually to the symlink-resolved current directory, an
entry in GIT_CEILING_DIRECTORIES that contained a symlink would have
no effect. It was known that this could cause performance problems
if the symlink resolution *itself* touched slow filesystems, but it
was thought that such use cases would be unlikely. The intention of
the earlier change was to deal with a case when the user has this:
GIT_CEILING_DIRECTORIES=/home/gitster
but in reality, /home/gitster is a symbolic link to somewhere else,
e.g. /net/machine/home4/gitster. A textual comparison between the
specified value /home/gitster and the location getcwd(3) returns
would not help us, but readlink("/home/gitster") would still be
fast.
After this change was released, Anders Kaseorg <andersk@mit.edu>
reported:
> [...] my computer has been acting so slow when I’m not connected to
> the network. I put various network filesystem paths in
> $GIT_CEILING_DIRECTORIES, such as
> /afs/athena.mit.edu/user/a/n/andersk (to avoid hitting its parents
> /afs/athena.mit.edu, /afs/athena.mit.edu/user/a, and
> /afs/athena.mit.edu/user/a/n which all live in different AFS
> volumes). Now when I’m not connected to the network, every
> invocation of Git, including the __git_ps1 in my shell prompt, waits
> for AFS to timeout.
To allow users to work around this problem, give them a mechanism to
turn off symlink resolution in GIT_CEILING_DIRECTORIES entries. All
the entries that follow an empty entry will not be checked for symbolic
links and used literally in comparison. E.g. with these:
GIT_CEILING_DIRECTORIES=:/foo/bar:/xyzzy or
GIT_CEILING_DIRECTORIES=/foo/bar::/xyzzy
we will not readlink("/xyzzy") because it comes after an empty entry.
With the former (but not with the latter), "/foo/bar" comes after an
empty entry, and we will not readlink it, either.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
073678b8e6 reworked the
mergetools/ directory so that every file corresponds to a
difftool-supported tool. When this happened the "defaults"
file went away as it was no longer needed by mergetool--lib.
t7800 tests that configured commands can override builtins,
but this test was not adjusted when the "defaults" file was
removed because the test continued to pass.
Adjust the test to use the everlasting "vimdiff" tool name
instead of "defaults" so that it correctly tests against a tool
that is known by mergetool--lib.
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If you are using autoconf and change the configure.ac, the
Makefile will notice that config.status is older than
configure.ac, and will attempt to rebuild and re-run the
configure script to pick up your changes. The first step in
doing so is to run "make configure". Unfortunately, this
tries to include config.mak.autogen, which depends on
config.status, which depends on configure.ac; so we must
rebuild config.status. Which leads to us running "make
configure", and so on.
It's easy to demonstrate with:
make configure
./configure
touch configure.ac
make
We can break this cycle by not re-invoking make to build
"configure", and instead just putting its rules inline into
our config.status rebuild procedure. We can avoid a copy by
factoring the rules into a make variable.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To talk with some sites that serve multiple names on a single IP
address, the client needs to ask for the specific host that it wants
to talk to.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Eliminate a lot of redundant work by using test_config().
Catch more return codes by more use of temporary files
and test_cmp.
The original tests relied upon restore_test_defaults()
from the previous test to provide the next test with a sane
environment. Make the tests do their own setup so that they
are not dependent on the success of the previous test.
The end result is shorter tests and better test isolation.
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most of the callers of packet_read_line just read into a
static 1000-byte buffer (callers which handle arbitrary
binary data already use LARGE_PACKET_MAX). This works fine
in practice, because:
1. The only variable-sized data in these lines is a ref
name, and refs tend to be a lot shorter than 1000
characters.
2. When sending ref lines, git-core always limits itself
to 1000 byte packets.
However, the only limit given in the protocol specification
in Documentation/technical/protocol-common.txt is
LARGE_PACKET_MAX; the 1000 byte limit is mentioned only in
pack-protocol.txt, and then only describing what we write,
not as a specific limit for readers.
This patch lets us bump the 1000-byte limit to
LARGE_PACKET_MAX. Even though git-core will never write a
packet where this makes a difference, there are two good
reasons to do this:
1. Other git implementations may have followed
protocol-common.txt and used a larger maximum size. We
don't bump into it in practice because it would involve
very long ref names.
2. We may want to increase the 1000-byte limit one day.
Since packets are transferred before any capabilities,
it's difficult to do this in a backwards-compatible
way. But if we bump the size of buffer the readers can
handle, eventually older versions of git will be
obsolete enough that we can justify bumping the
writers, as well. We don't have plans to do this
anytime soon, but there is no reason not to start the
clock ticking now.
Just bumping all of the reading bufs to LARGE_PACKET_MAX
would waste memory. Instead, since most readers just read
into a temporary buffer anyway, let's provide a single
static buffer that all callers can use. We can further wrap
this detail away by having the packet_read_line wrapper just
use the buffer transparently and return a pointer to the
static storage. That covers most of the cases, and the
remaining ones already read into their own LARGE_PACKET_MAX
buffers.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Having the packet sizes defined near the packet read/write
functions makes more sense.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The packets sent during ref negotiation are all terminated
by newline; even though the code to chomp these newlines is
short, we end up doing it in a lot of places.
This patch teaches packet_read_line to auto-chomp the
trailing newline; this lets us get rid of a lot of inline
chomping code.
As a result, some call-sites which are not reading
line-oriented data (e.g., when reading chunks of packfiles
alongside sideband) transition away from packet_read_line to
the generic packet_read interface. This patch converts all
of the existing callsites.
Since the function signature of packet_read_line does not
change (but its behavior does), there is a possibility of
new callsites being introduced in later commits, silently
introducing an incompatibility. However, since a later
patch in this series will change the signature, such a
commit would have to be merged directly into this commit,
not to the tip of the series; we can therefore ignore the
issue.
This is an internal cleanup and should produce no change of
behavior in the normal case. However, there is one corner
case to note. Callers of packet_read_line have never been
able to tell the difference between a flush packet ("0000")
and an empty packet ("0004"), as both cause packet_read_line
to return a length of 0. Readers treat them identically,
even though Documentation/technical/protocol-common.txt says
we must not; it also says that implementations should not
send an empty pkt-line.
By stripping out the newline before the result gets to the
caller, we will now treat the newline-only packet ("0005\n")
the same as an empty packet, which in turn gets treated like
a flush packet. In practice this doesn't matter, as neither
empty nor newline-only packets are part of git's protocols
(at least not for the line-oriented bits, and readers who
are not expecting line-oriented packets will be calling
packet_read directly, anyway). But even if we do decide to
care about the distinction later, it is orthogonal to this
patch. The right place to tighten would be to stop treating
empty packets as flush packets, and this change does not
make doing so any harder.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Originally we had a single function for reading packetized
data: packet_read_line. Commit 46284dd grew a more "gentle"
form, packet_read, that returns an error instead of dying
upon reading a truncated input stream. However, it is not
clear from the names which should be called, or what the
difference is.
Let's instead make packet_read be a generic public interface
that can take option flags, and update the single callsite
that uses it. This is less code, more clear, and paves the
way for introducing more options into the generic interface
later. The function signature is changed, so there should be
no hidden conflicts with topics in flight.
While we're at it, we'll document how error conditions are
handled based on the options, and rename the confusing
"return_line_fail" option to "gentle_on_eof". While we are
cleaning up the names, we can drop the "return_line_fail"
checks in packet_read_internal entirely. They look like
this:
ret = safe_read(..., return_line_fail);
if (return_line_fail && ret < 0)
...
The check for return_line_fail is a no-op; safe_read will
only ever return an error value if return_line_fail was true
in the first place.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is just write_or_die by another name. The one
distinction is that write_or_die will treat EPIPE specially
by suppressing error messages. That's fine, as we die by
SIGPIPE anyway (and in the off chance that it is disabled,
write_or_die will simulate it).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The comment describing the packet writing interface was
originally written above packet_write, but migrated to be
above safe_write in f3a3214, probably because it is meant to
generally describe the packet writing interface and not a
single function. Let's move it into the header file, where
users of the interface are more likely to see it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The write_or_die function will always die on an error,
including EPIPE. However, it currently treats EPIPE
specially by suppressing any error message, and by exiting
with exit code 0.
Suppressing the error message makes some sense; a pipe death
may just be a sign that the other side is not interested in
what we have to say. However, exiting with a successful
error code is not a good idea, as write_or_die is frequently
used in cases where we want to be careful about having
written all of the output, and we may need to signal to our
caller that we have done so (e.g., you would not want a push
whose other end has hung up to report success).
This distinction doesn't typically matter in git, because we
do not ignore SIGPIPE in the first place. Which means that
we will not get EPIPE, but instead will just die when we get
a SIGPIPE. But it's possible for a default handler to be set
by a parent process, or for us to add a callsite inside one
of our few SIGPIPE-ignoring blocks of code.
This patch converts write_or_die to actually raise SIGPIPE
when we see EPIPE, rather than exiting with zero. This
brings the behavior in line with the "normal" case that we
die from SIGPIPE (and any callers who want to check why we
died will see the same thing). We also give the same
treatment to other related functions, including
write_or_whine_pipe and maybe_flush_or_die.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The current parsing scheme for upload-archive is to pack
arguments into a fixed-size buffer, separated by NULs, and
put a pointer to each argument in the buffer into a
fixed-size argv array.
This works fine, and the limits are high enough that nobody
reasonable is going to hit them, but it makes the code hard
to follow. Instead, let's just stuff the arguments into an
argv_array, which is much simpler. That lifts the "all
arguments must fit inside 4K together" limit.
We could also trivially lift the MAX_ARGS limitation (in
fact, we have to keep extra code to enforce it). But that
would mean a client could force us to allocate an arbitrary
amount of memory simply by sending us "argument" lines. By
limiting the MAX_ARGS, we limit an attacker to about 4
megabytes (64 times a maximum 64K packet buffer). That may
sound like a lot compared to the 4K limit, but it's not a
big deal compared to what git-archive will actually allocate
while working (e.g., to load blobs into memory). The
important thing is that it is bounded.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
According to the comment, enter_repo will modify its input.
However, this has not been the case since 1c64b48
(enter_repo: do not modify input, 2011-10-04). Drop the
now-useless copy.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This code predates prefixcmp, so it used memcmp along with
static sizes. Replacing these memcmps with prefixcmp makes
the code much more readable, and the lack of static sizes
will make refactoring it in future patches simpler.
Note that we used to be unnecessarily liberal in parsing the
"unpack" status line, and would accept "unpack ok\njunk". No
version of git has ever produced that, and it violates the
BNF in Documentation/technical/pack-protocol.txt. Let's take
this opportunity to tighten the check by converting the
prefix comparison into a strcmp.
While we're in the area, let's also fix a vague error
message that does not follow our usual conventions (it
writes directly to stderr and does not use the "error:"
prefix).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we read acks from the remote, we expect either:
ACK <sha1>
or
ACK <sha1> <multi-ack-flag>
We parse the "ACK <sha1>" bit from the line, and then start
looking for the flag strings at "line+45"; if we don't have
them, we assume it's of the first type. But if we do have
the first type, then line+45 is not necessarily inside our
string at all!
It turns out that this works most of the time due to the way
we parse the packets. They should come in with a newline,
and packet_read puts an extra NUL into the buffer, so we end
up with:
ACK <sha1>\n\0
with the newline at offset 44 and the NUL at offset 45. We
then strip the newline, putting a NUL at offset 44. So
when we look at "line+45", we are looking past the end of
our string; but it's OK, because we hit the terminator from
the original string.
This breaks down, however, if the other side does not
terminate their packets with a newline. In that case, our
packet is one character shorter, and we start looking
through uninitialized memory for the flag. No known
implementation sends such a packet, so it has never come up
in practice.
This patch tightens the check by looking for a short,
flagless ACK before trying to parse the flag.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If you set the GIT_DEBUG_SEND_PACK environment variable,
upload-pack will dump lines it receives in the receive_needs
phase to a descriptor. This debugging harness is a strict
subset of what GIT_TRACE_PACKET can do. Let's just drop it
in favor of that.
A few tests used GIT_DEBUG_SEND_PACK to confirm which
objects get sent; we have to adapt them to the new output
format.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the client tells us it has a shallow object via
"shallow <sha1>", we make sure we have the object, mark it
with a flag, then add it to a dynamic array of shallow
objects. This means that a client can get us to allocate
arbitrary amounts of memory just by flooding us with shallow
lines (whether they have the objects or not). You can
demonstrate it easily with:
yes '0035shallow e83c5163316f89bfbde7d9ab23ca2e25604af290' |
git-upload-pack git.git
We already protect against duplicates in want lines by
checking if our flag is already set; let's do the same thing
here. Note that a client can still get us to allocate some
amount of memory by marking every object in the repo as
"shallow" (or "want"). But this at least bounds it with the
number of objects in the repository, which is not under the
control of an upload-pack client.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we receive a line like "shallow <sha1>" from the
client, we feed the <sha1> part to get_sha1. This is a
mistake, as the argument on a shallow line is defined by
Documentation/technical/pack-protocol.txt to contain an
"obj-id". This is never defined in the BNF, but it is clear
from the text and from the other uses that it is meant to be
a hex sha1, not an arbitrary identifier (and that is what
fetch-pack has always sent).
We should be using get_sha1_hex instead, which doesn't allow
the client to request arbitrary junk like "HEAD@{yesterday}".
Because this is just marking shallow objects, the client
couldn't actually do anything interesting (like fetching
objects from unreachable reflog entries), but we should keep
our parsing tight to be on the safe side.
Because get_sha1 is for the most part a superset of
get_sha1_hex, in theory the only behavior change should be
disallowing non-hex object references. However, there is
one interesting exception: get_sha1 will only parse
a 40-character hex sha1 if the string has exactly 40
characters, whereas get_sha1_hex will just eat the first 40
characters, leaving the rest. That means that current
versions of git-upload-pack will not accept a "shallow"
packet that has a trailing newline, even though the protocol
documentation is clear that newlines are allowed (even
encouraged) in non-binary parts of the protocol.
This never mattered in practice, though, because fetch-pack,
contrary to the protocol documentation, does not include a
newline in its shallow lines. JGit follows its lead (though
it correctly is strict on the parsing end about wanting a
hex object id).
We do not adjust fetch-pack to send newlines here, as it
would break communication with older versions of git (and
there is no actual benefit to doing so, except for
consistency with other parts of the protocol).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
