If our size computation overflows size_t, we may allocate a
much smaller buffer than we expected and overflow it. It's
probably impossible to trigger an overflow in most of these
sites in practice, but it is easy enough convert their
additions and multiplications into overflow-checking
variants. This may be fixing real bugs, and it makes
auditing the code easier.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Using FLEX_ARRAY macros reduces the amount of manual
computation size we have to do. It also ensures we don't
overflow size_t, and it makes sure we write the same number
of bytes that we allocated.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We frequently allocate strings as xmalloc(len + 1), where
the extra 1 is for the NUL terminator. This can be done more
simply with xmallocz, which also checks for integer
overflow.
There's no case where switching xmalloc(n+1) to xmallocz(n)
is wrong; the result is the same length, and malloc made no
guarantees about what was in the buffer anyway. But in some
cases, we can stop manually placing NUL at the end of the
allocated buffer. But that's only safe if it's clear that
the contents will always fill the buffer.
In each case where this patch does so, I manually examined
the control flow, and I tried to err on the side of caution.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Each of these cases can be converted to use ALLOC_ARRAY or
REALLOC_ARRAY, which has two advantages:
1. It automatically checks the array-size multiplication
for overflow.
2. It always uses sizeof(*array) for the element-size,
so that it can never go out of sync with the declared
type of the array.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are many manual argv allocations that predate the
argv_array API. Switching to that API brings a few
advantages:
1. We no longer have to manually compute the correct final
array size (so it's one less thing we can screw up).
2. In many cases we had to make a separate pass to count,
then allocate, then fill in the array. Now we can do it
in one pass, making the code shorter and easier to
follow.
3. argv_array handles memory ownership for us, making it
more obvious when things should be free()d and and when
not.
Most of these cases are pretty straightforward. In some, we
switch from "run_command_v" to "run_command" which lets us
directly use the argv_array embedded in "struct
child_process".
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The usual pattern for an argv array is to initialize it,
push in some strings, and then clear it when done. Very
occasionally, though, we must do other exotic things with
the memory, like freeing the list but keeping the strings.
Let's provide a detach function so that callers can make use
of our API to build up the array, and then take ownership of
it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Allocating a struct with a flex array is pretty simple in
practice: you over-allocate the struct, then copy some data
into the over-allocation. But it can be a slight pain to
make sure you're allocating and copying the right amounts.
This patch adds a few helpers to turn simple cases of
flex-array struct allocation into a one-liner that properly
checks for overflow. See the embedded documentation for
details.
Ideally we could provide a more flexible version that could
handle multiple strings, like:
FLEX_ALLOC_FMT(ref, name, "%s%s", prefix, name);
But we have to implement this as a macro (because of the
offset calculation of the flex member), which means we would
need all compilers to support variadic macros.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
REALLOC_ARRAY inherently involves a multiplication which can
overflow size_t, resulting in a much smaller buffer than we
think we've allocated. We can easily harden it by using
st_mult() to check for overflow. Likewise, we can add
ALLOC_ARRAY to do the same thing for xmalloc calls.
xcalloc() should already be fine, because it takes the two
factors separately, assuming the system calloc actually
checks for overflow. However, before we even hit the system
calloc(), we do our memory_limit_check, which involves a
multiplication. Let's check for overflow ourselves so that
this limit cannot be bypassed.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A combine_diff_path struct has two "flex" members allocated
alongside the struct: a string to hold the pathname, and an
array of parent pointers. We use an "int" to compute this,
meaning we may easily overflow it if the pathname is
extremely long.
We can fix this by using size_t, and checking for overflow
with the st_add helper.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Performing computations on size_t variables that we feed to
xmalloc and friends can be dangerous, as an integer overflow
can cause us to allocate a much smaller chunk than we
realized.
We already have unsigned_add_overflows(), but let's add
unsigned_mult_overflows() to that. Furthermore, rather than
have each site manually check and die on overflow, we can
provide some helpers that will:
- promote the arguments to size_t, so that we know we are
doing our computation in the same size of integer that
will ultimately be fed to xmalloc
- check and die on overflow
- return the result so that computations can be done in
the parameter list of xmalloc.
These functions are a lot uglier to use than normal
arithmetic operators (you have to do "st_add(foo, bar)"
instead of "foo + bar"). To at least limit the damage, we
also provide multi-valued versions. So rather than:
st_add(st_add(a, b), st_add(c, d));
you can write:
st_add4(a, b, c, d);
This isn't nearly as elegant as a varargs function, but it's
a lot harder to get it wrong. You don't have to remember to
add a sentinel value at the end, and the compiler will
complain if you get the number of arguments wrong. This
patch adds only the numbered variants required to convert
the current code base; we can easily add more later if
needed.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
You can tweak the reflog expiration for a particular subset
of refs by configuring gc.foo.reflogexpire. We keep a linked
list of reflog_expire_cfg structs, each of which holds the
pattern and a "len" field for the length of the pattern. The
pattern itself is _not_ NUL-terminated.
However, we feed the pattern directly to wildmatch(), which
expects a NUL-terminated string, meaning it may keep reading
random junk after our struct.
We can fix this by allocating an extra byte for the NUL
(which is already zero because we use xcalloc). Let's also
drop the misleading "len" field, which is no longer
necessary. The existing use of "len" can be converted to use
strncmp().
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation for "git fetch --depth" has been updated for clarity.
* ss/clone-depth-single-doc:
docs: clarify that --depth for git-fetch works with newly initialized repos
docs: say "commits" in the --depth option wording for git-clone
docs: clarify that passing --depth to git-clone implies --single-branch
Drop a few old "todo" items by deciding that the change one of them
suggests is not such a good idea, and doing the change the other
one suggested to do.
* ss/user-manual:
user-manual: add addition gitweb information
user-manual: add section documenting shallow clones
glossary: define the term shallow clone
user-manual: remove temporary branch entry from todo list
The underlying machinery used by "ls-files -o" and other commands
have been taught not to create empty submodule ref cache for a
directory that is not a submodule. This removes a ton of wasted
CPU cycles.
* jk/ref-cache-non-repository-optim:
resolve_gitlink_ref: ignore non-repository paths
clean: make is_git_repository a public function
dirname() emulation has been added, as Msys2 lacks it.
* js/dirname-basename:
mingw: avoid linking to the C library's isalpha()
t0060: loosen overly strict expectations
t0060: verify that basename() and dirname() work as expected
compat/basename.c: provide a dirname() compatibility function
compat/basename: make basename() conform to POSIX
Refactor skipping DOS drive prefixes
A few options of "git diff" did not work well when the command was
run from a subdirectory.
* nd/diff-with-path-params:
diff: make -O and --output work in subdirectory
diff-no-index: do not take a redundant prefix argument
The "split" subcommand of "git subtree" (in contrib/) incorrectly
skipped merges when it shouldn't, which was corrected.
* dw/subtree-split-do-not-drop-merge:
contrib/subtree: fix "subtree split" skipped-merge bug
"git tag" started listing a tag "foo" as "tags/foo" when a branch
named "foo" exists in the same repository; remove this unnecessary
disambiguation, which is a regression introduced in v2.7.0.
* jk/list-tag-2.7-regression:
tag: do not show ambiguous tag names as "tags/foo"
t6300: use test_atom for some un-modern tests
The description for SANITY prerequisite the test suite uses has
been clarified both in the comment and in the implementation.
* jk/sanity:
test-lib: clarify and tighten SANITY
A recent optimization to filter-branch in v2.7.0 introduced a
regression when --prune-empty filter is used, which has been
corrected.
* jk/filter-branch-no-index:
filter-branch: resolve $commit^{tree} in no-index case
Many codepaths that run "gc --auto" before exiting kept packfiles
mapped and left the file descriptors to them open, which was not
friendly to systems that cannot remove files that are open. They
now close the packs before doing so.
* js/close-packs-before-gc:
receive-pack: release pack files before garbage-collecting
merge: release pack files before garbage-collecting
am: release pack files before garbage-collecting
fetch: release pack files before garbage-collecting
"git rebase", unlike all other callers of "gc --auto", did not
ignore the exit code from "gc --auto".
* jk/ok-to-fail-gc-auto-in-rebase:
rebase: ignore failures from "gc --auto"
Asking gitweb for a nonexistent commit left a warning in the server
log.
Somebody may want to follow this up with a new test, perhaps?
IIRC, we do test that no Perl warnings are given to the server log,
so this should have been caught if our test coverage were good.
* ho/gitweb-squelch-undef-warning:
gitweb: squelch "uninitialized value" warning
Some codepaths used fopen(3) when opening a fixed path in $GIT_DIR
(e.g. COMMIT_EDITMSG) that is meant to be left after the command is
done. This however did not work well if the repository is set to
be shared with core.sharedRepository and the umask of the previous
user is tighter. They have been made to work better by calling
unlink(2) and retrying after fopen(3) fails with EPERM.
* js/fopen-harder:
Handle more file writes correctly in shared repos
commit: allow editing the commit message even in shared repos
The ignore mechanism saw a few regressions around untracked file
listing and sparse checkout selection areas in 2.7.0; the change
that is responsible for the regression has been reverted.
* nd/exclusion-regression-fix:
Revert "dir.c: don't exclude whole dir prematurely if neg pattern may match"
"git reflog" incorrectly assumed that all objects that used to be
at the tip of a ref must be commits, which caused it to segfault.
* dk/reflog-walk-with-non-commit:
reflog-walk: don't segfault on non-commit sha1's in the reflog
The documentation has been updated to hint the connection between
the '--signoff' option and DCO.
* dw/signoff-doc:
Expand documentation describing --signoff
A few unportable C construct have been spotted by clang compiler
and have been fixed.
* jk/clang-pedantic:
bswap: add NO_UNALIGNED_LOADS define
avoid shifting signed integers 31 bits
"git send-email" was confused by escaped quotes stored in the alias
files saved by "mutt", which has been corrected.
* ew/send-email-mutt-alias-fix:
git-send-email: do not double-escape quotes from mutt
The "exclude_list" structure has the usual "alloc, nr" pair of
fields to be used by ALLOC_GROW(), but clear_exclude_list() forgot
to reset 'alloc' to 0 when it cleared 'nr' to discard the managed
array.
* nd/dir-exclude-cleanup:
dir.c: clean the entire struct in clear_exclude_list()
An earlier change in 2.5.x-era broke users' hooks and aliases by
exporting GIT_WORK_TREE to point at the root of the working tree,
interfering when they tried to use a different working tree without
setting GIT_WORK_TREE environment themselves.
* nd/stop-setenv-work-tree:
Revert "setup: set env $GIT_WORK_TREE when work tree is set, like $GIT_DIR"
For users with "store-passwords = no" set in the "[auth]" section of
their ~/.subversion/config, SVN 1.9.0+ would fail with the
following message when attempting to call svn_auth_set_parameter:
Value is not a string (or undef) at Git/SVN/Ra.pm
Ironically, this breakage was caused by r1553823 in subversion:
"Make svn_auth_set_parameter() usable from Perl bindings."
Since 2007 (602015e0e6), git-svn has used a workaround to make
svn_auth_set_parameter usable internally. However this workaround
breaks under SVN 1.9+, which deals properly with the type mapping
and fails to recognize our workaround.
For pre-1.9.0 SVN, we continue to use the existing workaround for
the lack of proper type mapping in the bindings.
Tested under subversion 1.6.17 and 1.9.3.
I've also verified r1553823 was not backported to SVN 1.8.x:
BRANCH=http://svn.apache.org/repos/asf/subversion/branches/1.8.x
svn log -v $BRANCH/subversion/bindings/swig/core.i
ref: https://bugs.debian.org/797705
Cc: 797705@bugs.debian.org
Reported-by: Thierry Vignaud <thierry.vignaud@gmail.com>
Signed-off-by: Eric Wong <normalperson@yhbt.net>
Tested-by: Thierry Vignaud <thierry.vignaud@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since b7cc53e9 (tag.c: use 'ref-filter' APIs, 2015-07-11),
git-tag has started showing tags with ambiguous names (i.e.,
when both "heads/foo" and "tags/foo" exists) as "tags/foo"
instead of just "foo". This is both:
- pointless; the output of "git tag" includes only
refs/tags, so we know that "foo" means the one in
"refs/tags".
and
- ambiguous; in the original output, we know that the line
"foo" means that "refs/tags/foo" exists. In the new
output, it is unclear whether we mean "refs/tags/foo" or
"refs/tags/tags/foo".
The reason this happens is that commit b7cc53e9 switched
git-tag to use ref-filter's "%(refname:short)" output
formatting, which was adapted from for-each-ref. This more
general code does not know that we care only about tags, and
uses shorten_unambiguous_ref to get the short-name. We need
to tell it that we care only about "refs/tags/", and it
should shorten with respect to that value.
In theory, the ref-filter code could figure this out by us
passing FILTER_REFS_TAGS. But there are two complications
there:
1. The handling of refname:short is deep in formatting
code that does not even have our ref_filter struct, let
alone the arguments to the filter_ref struct.
2. In git v2.7.0, we expose the formatting language to the
user. If we follow this path, it will mean that
"%(refname:short)" behaves differently for "tag" versus
"for-each-ref" (including "for-each-ref refs/tags/"),
which can lead to confusion.
Instead, let's add a new modifier to the formatting
language, "strip", to remove a specific set of prefix
components. This fixes "git tag", and lets users invoke the
same behavior from their own custom formats (for "tag" or
"for-each-ref") while leaving ":short" with its same
consistent meaning in all places.
We introduce a test in t7004 for "git tag", which fails
without this patch. We also add a similar test in t3203 for
"git branch", which does not actually fail. But since it is
likely that "branch" will eventually use the same formatting
code, the test helps defend against future regressions.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add --all and --include-untracked to the git stash save completions.
Add --quiet to the git stash drop completions.
Update git stash branch so that the first argument expands out to the
possible branch names, and the other arguments expand to the stash
names.
Signed-off-by: Paul Wagland <paul@kungfoocoder.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This adds the --no-* variants where those are documented in
git-rebase(1).
Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The implementation of mingw_skip_dos_drive_prefix() calls isalpha() via
has_dos_drive_prefix(). Since the definition occurs long before isalpha()
is defined in git-compat-util.h, my build environment reports:
CC alloc.o
In file included from git-compat-util.h:186,
from cache.h:4,
from alloc.c:12:
compat/mingw.h: In function 'mingw_skip_dos_drive_prefix':
compat/mingw.h:365: warning: implicit declaration of function 'isalpha'
Dscho does not see a similar warning in his build and suspects that
ctype.h is included somehow behind the scenes. This implies that his build
links to the C library's isalpha() and does not use git's isalpha().
To fix both the warning in my build and the inconsistency in Dscho's
build, move the function definition to mingw.c. Then it picks up git's
isalpha() because git-compat-util.h is included at the top of the file.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Because this script has to test so many formatters, we have
the nice "test_atom" helper, but we don't use it
consistently. Let's do so. This is shorter, gets rid of some
tests that have their "expected" setup outside of a
test_expect_success block, and lets us organize the changes
better (e.g., putting "refname:short" near "refname").
We also expand the "%(push)" tests a little to match the
"%(upstream)" ones.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we want to look up a submodule ref, we use
get_ref_cache(path) to find or auto-create its ref cache.
But if we feed a path that isn't actually a git repository,
we blindly create the ref cache, and then may die deeper in
the code when we try to access it. This is a problem because
many callers speculatively feed us a path that looks vaguely
like a repository, and expect us to tell them when it is
not.
This patch teaches resolve_gitlink_ref to reject
non-repository paths without creating a ref_cache. This
avoids the die(), and also performs better if you have a
large number of these faux-submodule directories (because
the ref_cache lookup is linear, under the assumption that
there won't be a large number of submodules).
To accomplish this, we also break get_ref_cache into two
pieces: the lookup and auto-creation (the latter is lumped
into create_ref_cache). This lets us first cheaply ask our
cache "is it a submodule we know about?" If so, we can avoid
repeating our filesystem lookup. So lookups of real
submodules are not penalized; they examine the submodule's
.git directory only once.
The test in t3000 demonstrates a case where this improves
correctness (we used to just die). The new perf case in
p7300 shows off the speed improvement in an admittedly
pathological repository:
Test HEAD^ HEAD
----------------------------------------------------------------
7300.4: ls-files -o 66.97(66.15+0.87) 0.33(0.08+0.24) -99.5%
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have always had is_git_directory(), for looking at a
specific directory to see if it contains a git repo. In
0179ca7 (clean: improve performance when removing lots of
directories, 2015-06-15), we added is_git_repository() which
checks for a non-bare repository by looking at its ".git"
entry.
However, the fix in 0179ca7 needs to be applied other
places, too. Let's make this new helper globally available.
We need to give it a better name, though, to avoid confusion
with is_git_directory(). This patch does that, documents
both functions with a comment to reduce confusion, and
removes the clean-specific references in the comments.
Based-on-a-patch-by: Andreas Krey <a.krey@gmx.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
