The prior commit converted many sites to check the return
value of write_in_full() for negativity, rather than a
mismatch with the input length. This patch covers similar
cases, but where the return value is stored in an
intermediate variable. These should get the same treatment,
but they need to be reviewed more carefully since it would
be a bug if the return value is stored in an unsigned type
(which indeed, it is in one of the cases).
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The return value of write_in_full() is either "-1", or the
requested number of bytes[1]. If we make a partial write
before seeing an error, we still return -1, not a partial
value. This goes back to f6aa66cb95 (write_in_full: really
write in full or return error on disk full., 2007-01-11).
So checking anything except "was the return value negative"
is pointless. And there are a couple of reasons not to do
so:
1. It can do a funny signed/unsigned comparison. If your
"len" is signed (e.g., a size_t) then the compiler will
promote the "-1" to its unsigned variant.
This works out for "!= len" (unless you really were
trying to write the maximum size_t bytes), but is a
bug if you check "< len" (an example of which was fixed
recently in config.c).
We should avoid promoting the mental model that you
need to check the length at all, so that new sites are
not tempted to copy us.
2. Checking for a negative value is shorter to type,
especially when the length is an expression.
3. Linus says so. In d34cf19b89 (Clean up write_in_full()
users, 2007-01-11), right after the write_in_full()
semantics were changed, he wrote:
I really wish every "write_in_full()" user would just
check against "<0" now, but this fixes the nasty and
stupid ones.
Appeals to authority aside, this makes it clear that
writing it this way does not have an intentional
benefit. It's a historical curiosity that we never
bothered to clean up (and which was undoubtedly
cargo-culted into new sites).
So let's convert these obviously-correct cases (this
includes write_str_in_full(), which is just a wrapper for
write_in_full()).
[1] A careful reader may notice there is one way that
write_in_full() can return a different value. If we ask
write() to write N bytes and get a return value that is
_larger_ than N, we could return a larger total. But
besides the fact that this would imply a totally broken
version of write(), it would already invoke undefined
behavior. Our internal remaining counter is an unsigned
size_t, which means that subtracting too many byte will
wrap it around to a very large number. So we'll instantly
begin reading off the end of the buffer, trying to write
gigabytes (or petabytes) of data.
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We ask to write 41 bytes and make sure that the return value
is at least 41. This is the same "dangerous" pattern that
was fixed in the prior commit (wherein a negative return
value is promoted to unsigned), though it is not dangerous
here because our "41" is a constant, not an unsigned
variable.
But we should convert it anyway to avoid modeling a
dangerous construct.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The return type of write_in_full() is a signed ssize_t,
because we may return "-1" on failure (even if we succeeded
in writing some bytes). But "len" itself is may be an
unsigned type (the function takes a size_t, but of course we
may have something else in the calling function). So while
it seems like:
if (write_in_full(fd, buf, len) < len)
die_errno("write error");
would trigger on error, it won't if "len" is unsigned. The
compiler sees a signed/unsigned comparison and promotes the
signed value, resulting in (size_t)-1, the highest possible
size_t (or again, whatever type the caller has). This cannot
possibly be smaller than "len", and so the conditional can
never trigger.
I scoured the code base for cases of this, but it turns out
that these two in git_config_set_multivar_in_file_gently()
are the only ones. Here our "len" is the difference between
two size_t variables, making the result an unsigned size_t.
We can fix this by just checking for a negative return value
directly, as write_in_full() will never return any value
except -1 or the full count.
There's no addition to the test suite here, since you need
to convince write() to fail in order to see the problem. The
simplest reproduction recipe I came up with is to trigger
ENOSPC:
# make a limited-size filesystem
dd if=/dev/zero of=small.disk bs=1M count=1
mke2fs small.disk
mkdir mnt
sudo mount -o loop small.disk mnt
cd mnt
sudo chown $USER:$USER .
# make a config file with some content
git config --file=config one.key value
git config --file=config two.key value
# now fill up the disk
dd if=/dev/zero of=fill
# and try to delete a key, which requires copying the rest
# of the file to config.lock, and will fail on write()
git config --file=config --unset two.key
That final command should (and does after this patch)
produce an error message due to the failed write, and leave
the file intact. Instead, it silently ignores the failure
and renames config.lock into place, leaving you with a
totally empty config file!
Reported-by: demerphq <demerphq@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Following are several fixes for duplicated words ("of of") and one
case where an extra article ("a") slipped in.
Signed-off-by: Evan Zacks <zackse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While git doesn't track empty directories, git archive can be tricked
into putting some into archives. One way is to construct an empty tree
object, as t5004 does. While that is supported by the object database,
it can't be represented in the index and thus it's unlikely to occur in
the wild.
Another way is using the literal name of a directory in an exclude
pathspec -- its contents are are excluded, but the directory stub is
included. That's inconsistent: exclude pathspecs containing wildcards
don't leave empty directories in the archive.
Yet another way is have a few levels of nested subdirectories (e.g.
d1/d2/d3/file1) and ignoring the entries at the leaves (e.g. file1).
The directories with the ignored content are ignored as well (e.g. d3),
but their empty parents are included (e.g. d2).
As empty directories are not supported by git, they should also not be
written into archives. If an empty directory is really needed then it
can be tracked and archived by placing an empty .gitignore file in it.
There already is a mechanism in place for suppressing empty directories.
When read_tree_recursive() encounters a directory excluded by a pathspec
then it enters it anyway because it might contain included entries. It
calls the callback function before it is able to decide if the directory
is actually needed. For that reason git archive adds directories to a
queue and writes entries for them only when it encounters the first
child item -- but currently only if pathspecs with wildcards are used.
Queue *all* directories, no matter if there even are pathspecs present.
This prevents git archive from writing entries for empty directories in
all cases.
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Callers are only allowed to pass certain flags into
ref_transaction_update, other flags are internal to it. To prevent
mistakes from the callers, strip the internal only flags out before
continuing.
This was noticed because of a compiler warning gcc 7.1.1 issued about
passing a NULL parameter as second parameter to memcpy (through
hashcpy):
In file included from refs.c:5:0:
refs.c: In function ‘ref_transaction_verify’:
cache.h:948:2: error: argument 2 null where non-null expected [-Werror=nonnull]
memcpy(sha_dst, sha_src, GIT_SHA1_RAWSZ);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from git-compat-util.h:165:0,
from cache.h:4,
from refs.c:5:
/usr/include/string.h:43:14: note: in a call to function ‘memcpy’ declared here
extern void *memcpy (void *__restrict __dest, const void *__restrict __src,
^~~~~~
The call to hascpy in ref_transaction_add_update is protected by the
passed in flags, but as we only add flags there, gcc notices
REF_HAVE_NEW or REF_HAVE_OLD flags could be passed in from the outside,
which would potentially result in passing in NULL as second parameter to
memcpy.
Fix both the compiler warning, and make the interface safer for its
users by stripping the internal flags out.
Suggested-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
For count, sort and format, only the argument names were listed under
OPTIONS, not the option names.
Add the option names to make it clear the options exist
Signed-off-by: Kevin Daudt <me@ikke.info>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The synopsis and description inconsistently add a '=' between the
argument name and it's value. Make this consistent.
Signed-off-by: Kevin Daudt <me@ikke.info>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We run `git rev-parse` though the shell, and quote its
argument only with single-quotes. This prevents most
metacharacters from being a problem, but misses the obvious
case when $name itself has single-quotes in it. We can fix
this by applying the usual shell-quoting formula.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Refnames can contain shell metacharacters which need to be
passed verbatim to sub-processes. Using safe_pipe_capture
skips the shell entirely.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git-cvsserver script is old and largely unmaintained
these days. But git-shell allows untrusted users to run it
out of the box, significantly increasing its attack surface.
Let's drop it from git-shell's list of internal handlers so
that it cannot be run by default. This is not backwards
compatible. But given the age and development activity on
CVS-related parts of Git, this is likely to impact very few
users, while helping many more (i.e., anybody who runs
git-shell and had no intention of supporting CVS).
There's no configuration mechanism in git-shell for us to
add a boolean and flip it to "off". But there is a mechanism
for adding custom commands, and adding CVS support here is
fairly trivial. Let's document it to give guidance to
anybody who really is still running cvsserver.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This makes the script pass arguments that are derived from end-user
input in safer way when invoking subcommands.
Reported-by: joernchen <joernchen@phenoelit.de>
Signed-off-by: joernchen <joernchen@phenoelit.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As a preparation for replacing `command` with a call to this
function from outside GITCVS::updater package, move it to the main
package.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The handshake_capabilities() function first advertises the set of
capabilities it supports, so that the other side can pick and choose
which ones to use and ask us to enable in its response. Then we
read the response that tells us what choice the other side made. If
we saw something that we never advertised, that indicates one of two
things. The other side, i.e. the "upgraded" filter, is not paying
attention of the capabilities advertisement, and asking something
its correct operation relies on, but we are not capable of giving
that unknown feature and operate without it, so after that point the
exchange of data is a garbage-in-garbage-out. Or the other side
wanted to ask for one of the capabilities we advertised, but the
code has typo and their wish to enable a capability that its correct
operation relies on is not understood on this end. The result is
the same garbage-in-garbage-out.
Instead of sweeping such a potential bug under the rug, die loudly
when we see a request for an unsupported capability in order to
force sloppily-written filter scripts to get corrected.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If we push a branch and a tag pointing to the HEAD of this branch,
then Travis CI would run the build twice. This wastes resources and
slows the testing.
Add a function to detect this situation and skip the build the branch
if appropriate. Invoke this function on every build.
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most of the Travis CI commands are in the '.travis.yml'. The yml format
does not support functions and therefore code duplication is necessary
to run commands across all builds.
To fix this, add a library for common CI functions. Move all Travis CI
code into dedicated scripts and make them call the library first.
Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Doc fix.
* mg/format-ref-doc-fix:
Documentation/git-for-each-ref: clarify peeling of tags for --format
Documentation: use proper wording for ref format strings
"git archive" did not work well with pathspecs and the
export-ignore attribute.
We may want to resurrect the "we don't archive an empty directory"
bonus patch, but I do not mind merging the above early to 'next'
and leave it as a separate follow-up enhancement.
cf. <20170820090629.tumvqwzkromcykjf@sigill.intra.peff.net>
* rs/archive-excluded-directory:
archive: don't queue excluded directories
archive: factor out helper functions for handling attributes
t5001: add tests for export-ignore attributes and exclude pathspecs
Killing "git merge --edit" before the editor returns control left
the repository in a state with MERGE_MSG but without MERGE_HEAD,
which incorrectly tells the subsequent "git commit" that there was
a squash merge in progress. This has been fixed.
* mg/killed-merge:
merge: save merge state earlier
merge: split write_merge_state in two
merge: clarify call chain
Documentation/git-merge: explain --continue
"git apply" that is used as a better "patch -p1" failed to apply a
taken from a file with CRLF line endings to a file with CRLF line
endings. The root cause was because it misused convert_to_git()
that tried to do "safe-crlf" processing by looking at the index
entry at the same path, which is a nonsense---in that mode, "apply"
is not working on the data in (or derived from) the index at all.
This has been fixed.
* tb/apply-with-crlf:
apply: file commited with CRLF should roundtrip diff and apply
convert: add SAFE_CRLF_KEEP_CRLF
When handshake with a subprocess filter notices that the process
asked for an unknown capability, Git did not report what program
the offending subprocess was running. This has been corrected.
We may want a follow-up fix to tighten the error checking, though.
* cc/subprocess-handshake-missing-capabilities:
sub-process: print the cmd when a capability is unsupported
"git grep -L" and "git grep --quiet -L" reported different exit
codes; this has been corrected.
* as/grep-quiet-no-match-exit-code-fix:
git-grep: correct exit code with --quiet and -L
bash 4.4 or newer gave a warning on NUL byte in command
substitution done in "git stash"; this has been squelched.
* kd/stash-with-bash-4.4:
stash: prevent warning about null bytes in input
"git svn" used with "--localtime" option did not compute the tz
offset for the timestamp in question and instead always used the
current time, which has been corrected.
* ur/svn-local-zone:
git svn fetch: Create correct commit timestamp when using --localtime
