Our handling of alternate object directories is needlessly different
from the main object directory. As a result, many places in the code
basically look like this:
do_something(r->objects->objdir);
for (odb = r->objects->alt_odb_list; odb; odb = odb->next)
do_something(odb->path);
That gets annoying when do_something() is non-trivial, and we've
resorted to gross hacks like creating fake alternates (see
find_short_object_filename()).
Instead, let's give each raw_object_store a unified list of
object_directory structs. The first will be the main store, and
everything after is an alternate. Very few callers even care about the
distinction, and can just loop over the whole list (and those who care
can just treat the first element differently).
A few observations:
- we don't need r->objects->objectdir anymore, and can just
mechanically convert that to r->objects->odb->path
- object_directory's path field needs to become a real pointer rather
than a FLEX_ARRAY, in order to fill it with expand_base_dir()
- we'll call prepare_alt_odb() earlier in many functions (i.e.,
outside of the loop). This may result in us calling it even when our
function would be satisfied looking only at the main odb.
But this doesn't matter in practice. It's not a very expensive
operation in the first place, and in the majority of cases it will
be a noop. We call it already (and cache its results) in
prepare_packed_git(), and we'll generally check packs before loose
objects. So essentially every program is going to call it
immediately once per program.
Arguably we should just prepare_alt_odb() immediately upon setting
up the repository's object directory, which would save us sprinkling
calls throughout the code base (and forgetting to do so has been a
source of subtle bugs in the past). But I've stopped short of that
here, since there are already a lot of other moving parts in this
patch.
- Most call sites just get shorter. The check_and_freshen() functions
are an exception, because they have entry points to handle local and
nonlocal directories separately.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If a "char" in C is signed or unsigned is not specified, because it is
out of tradition "implementation dependent".
Therefore constructs like "if (name[i] < 0)" are not portable,
use "if (name[i] & 0x80)" instead.
Detected by "gcc (Raspbian 6.3.0-18+rpi1+deb9u1) 6.3.0 20170516" when
setting
DEVELOPER = 1
DEVOPTS = extra-all
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When multiple worktrees are used, we need rules to determine if
something belongs to one worktree or all of them. Instead of keeping
adding rules when new stuff comes (*), have a generic rule:
- Inside $GIT_DIR, which is per-worktree by default, add
$GIT_DIR/common which is always shared. New features that want to
share stuff should put stuff under this directory.
- Inside refs/, which is shared by default except refs/bisect, add
refs/worktree/ which is per-worktree. We may eventually move
refs/bisect to this new location and remove the exception in refs
code.
(*) And it may also include stuff from external commands which will
have no way to modify common/per-worktree rules.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The conversion to pass "the_repository" and then "a_repository"
throughout the object access API continues.
* sb/object-store-grafts:
commit: allow lookup_commit_graft to handle arbitrary repositories
commit: allow prepare_commit_graft to handle arbitrary repositories
shallow: migrate shallow information into the object parser
path.c: migrate global git_path_* to take a repository argument
cache: convert get_graft_file to handle arbitrary repositories
commit: convert read_graft_file to handle arbitrary repositories
commit: convert register_commit_graft to handle arbitrary repositories
commit: convert commit_graft_pos() to handle arbitrary repositories
shallow: add repository argument to is_repository_shallow
shallow: add repository argument to check_shallow_file_for_update
shallow: add repository argument to register_shallow
shallow: add repository argument to set_alternate_shallow_file
commit: add repository argument to lookup_commit_graft
commit: add repository argument to prepare_commit_graft
commit: add repository argument to read_graft_file
commit: add repository argument to register_commit_graft
commit: add repository argument to commit_graft_pos
object: move grafts to object parser
object-store: move object access functions to object-store.h
* maint-2.14:
Git 2.14.4
Git 2.13.7
verify_path: disallow symlinks in .gitmodules
update-index: stat updated files earlier
verify_dotfile: mention case-insensitivity in comment
verify_path: drop clever fallthrough
skip_prefix: add case-insensitive variant
is_{hfs,ntfs}_dotgitmodules: add tests
is_ntfs_dotgit: match other .git files
is_hfs_dotgit: match other .git files
is_ntfs_dotgit: use a size_t for traversing string
submodule-config: verify submodule names as paths
* maint-2.13:
Git 2.13.7
verify_path: disallow symlinks in .gitmodules
update-index: stat updated files earlier
verify_dotfile: mention case-insensitivity in comment
verify_path: drop clever fallthrough
skip_prefix: add case-insensitive variant
is_{hfs,ntfs}_dotgitmodules: add tests
is_ntfs_dotgit: match other .git files
is_hfs_dotgit: match other .git files
is_ntfs_dotgit: use a size_t for traversing string
submodule-config: verify submodule names as paths
When we started to catch NTFS short names that clash with .git, we only
looked for GIT~1. This is sufficient because we only ever clone into an
empty directory, so .git is guaranteed to be the first subdirectory or
file in that directory.
However, even with a fresh clone, .gitmodules is *not* necessarily the
first file to be written that would want the NTFS short name GITMOD~1: a
malicious repository can add .gitmodul0000 and friends, which sorts
before `.gitmodules` and is therefore checked out *first*. For that
reason, we have to test not only for ~1 short names, but for others,
too.
It's hard to just adapt the existing checks in is_ntfs_dotgit(): since
Windows 2000 (i.e., in all Windows versions still supported by Git),
NTFS short names are only generated in the <prefix>~<number> form up to
number 4. After that, a *different* prefix is used, calculated from the
long file name using an undocumented, but stable algorithm.
For example, the short name of .gitmodules would be GITMOD~1, but if it
is taken, and all of ~2, ~3 and ~4 are taken, too, the short name
GI7EBA~1 will be used. From there, collisions are handled by
incrementing the number, shortening the prefix as needed (until ~9999999
is reached, in which case NTFS will not allow the file to be created).
We'd also want to handle .gitignore and .gitattributes, which suffer
from a similar problem, using the fall-back short names GI250A~1 and
GI7D29~1, respectively.
To accommodate for that, we could reimplement the hashing algorithm, but
it is just safer and simpler to provide the known prefixes. This
algorithm has been reverse-engineered and described at
https://usn.pw/blog/gen/2015/06/09/filenames/, which is defunct but
still available via https://web.archive.org/.
These can be recomputed by running the following Perl script:
-- snip --
use warnings;
use strict;
sub compute_short_name_hash ($) {
my $checksum = 0;
foreach (split('', $_[0])) {
$checksum = ($checksum * 0x25 + ord($_)) & 0xffff;
}
$checksum = ($checksum * 314159269) & 0xffffffff;
$checksum = 1 + (~$checksum & 0x7fffffff) if ($checksum & 0x80000000);
$checksum -= (($checksum * 1152921497) >> 60) * 1000000007;
return scalar reverse sprintf("%x", $checksum & 0xffff);
}
print compute_short_name_hash($ARGV[0]);
-- snap --
E.g., running that with the argument ".gitignore" will
result in "250a" (which then becomes "gi250a" in the code).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff King <peff@peff.net>
We walk through the "name" string using an int, which can
wrap to a negative value and cause us to read random memory
before our array (e.g., by creating a tree with a name >2GB,
since "int" is still 32 bits even on most 64-bit platforms).
Worse, this is easy to trigger during the fsck_tree() check,
which is supposed to be protecting us from malicious
garbage.
Note one bit of trickiness in the existing code: we
sometimes assign -1 to "len" at the end of the loop, and
then rely on the "len++" in the for-loop's increment to take
it back to 0. This is still legal with a size_t, since
assigning -1 will turn into SIZE_MAX, which then wraps
around to 0 on increment.
Signed-off-by: Jeff King <peff@peff.net>
Migrate all git_path_* functions that are defined in path.c to take a
repository argument. Unlike other patches in this series, do not use the
#define trick, as we rewrite the whole function, which is rather small.
This doesn't migrate all the functions, as other builtins have their own
local path functions defined using GIT_PATH_FUNC. So keep that macro
around to serve the other locations.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The raw object store field will contain any objects needed for access
to objects in a given repository.
This patch introduces the raw object store and populates it with the
`objectdir`, which used to be part of the repository struct.
As the struct gains members, we'll also populate the function to clear
the memory for these members.
In a later step, we'll introduce a struct object_parser, that will
complement the object parsing in a repository struct: The raw object
parser is the layer that will provide access to raw object content,
while the higher level object parser code will parse raw objects and
keeps track of parenthood and other object relationships using 'struct
object'. For now only add the lower level to the repository struct.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A possible oom error is now caught as a fatal error, instead of
continuing and dereferencing NULL.
* ao/path-use-xmalloc:
path.c: use xmalloc() in add_to_trie()
Add usage of xmalloc() instead of malloc() in add_to_trie() as xmalloc wraps
and checks memory allocation result.
Signed-off-by: Andrey Okoshkin <a.okoshkin@samsung.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code clean-up.
* jk/validate-headref-fix:
validate_headref: use get_oid_hex for detached HEADs
validate_headref: use skip_prefix for symref parsing
validate_headref: NUL-terminate HEAD buffer
Fixes for a handful memory access issues identified by valgrind.
* tg/memfixes:
sub-process: use child_process.args instead of child_process.argv
http-push: fix construction of hex value from path
path.c: fix uninitialized memory access
Code clean-up.
* rs/cleanup-strbuf-users:
graph: use strbuf_addchars() to add spaces
use strbuf_addstr() for adding strings to strbufs
path: use strbuf_add_real_path()
In cleanup_path we're passing in a char array, run a memcmp on it, and
run through it without ever checking if something is in the array in the
first place. This can lead us to access uninitialized memory, for
example in t5541-http-push-smart.sh test 7, when run under valgrind:
==4423== Conditional jump or move depends on uninitialised value(s)
==4423== at 0x242FA9: cleanup_path (path.c:35)
==4423== by 0x242FA9: mkpath (path.c:456)
==4423== by 0x256CC7: refname_match (refs.c:364)
==4423== by 0x26C181: count_refspec_match (remote.c:1015)
==4423== by 0x26C181: match_explicit_lhs (remote.c:1126)
==4423== by 0x26C181: check_push_refs (remote.c:1409)
==4423== by 0x2ABB4D: transport_push (transport.c:870)
==4423== by 0x186703: push_with_options (push.c:332)
==4423== by 0x18746D: do_push (push.c:409)
==4423== by 0x18746D: cmd_push (push.c:566)
==4423== by 0x1183E0: run_builtin (git.c:352)
==4423== by 0x11973E: handle_builtin (git.c:539)
==4423== by 0x11973E: run_argv (git.c:593)
==4423== by 0x11973E: main (git.c:698)
==4423== Uninitialised value was created by a heap allocation
==4423== at 0x4C2CD8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==4423== by 0x4C2F195: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==4423== by 0x2C196B: xrealloc (wrapper.c:137)
==4423== by 0x29A30B: strbuf_grow (strbuf.c:66)
==4423== by 0x29A30B: strbuf_vaddf (strbuf.c:277)
==4423== by 0x242F9F: mkpath (path.c:454)
==4423== by 0x256CC7: refname_match (refs.c:364)
==4423== by 0x26C181: count_refspec_match (remote.c:1015)
==4423== by 0x26C181: match_explicit_lhs (remote.c:1126)
==4423== by 0x26C181: check_push_refs (remote.c:1409)
==4423== by 0x2ABB4D: transport_push (transport.c:870)
==4423== by 0x186703: push_with_options (push.c:332)
==4423== by 0x18746D: do_push (push.c:409)
==4423== by 0x18746D: cmd_push (push.c:566)
==4423== by 0x1183E0: run_builtin (git.c:352)
==4423== by 0x11973E: handle_builtin (git.c:539)
==4423== by 0x11973E: run_argv (git.c:593)
==4423== by 0x11973E: main (git.c:698)
==4423==
Avoid this by using skip_prefix(), which knows not to go beyond the
end of the string.
Reported-by: Thomas Gummerer <t.gummerer@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>
Code clean-up.
* jk/validate-headref-fix:
validate_headref: use get_oid_hex for detached HEADs
validate_headref: use skip_prefix for symref parsing
validate_headref: NUL-terminate HEAD buffer
Avoid a string copy to a static buffer by using strbuf_add_real_path()
instead of combining strbuf_addstr() and real_path().
Patch generated by Coccinelle and contrib/coccinelle/strbuf.cocci.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If a candidate HEAD isn't a symref, we check that it
contains a viable sha1. But in a post-sha1 world, we should
be checking whether it has any plausible object-id.
We can do that by switching to get_oid_hex().
Note that both before and after this patch, we only check
for a plausible object id at the start of the file, and then
call that good enough. We ignore any content _after_ the
hex, so a string like:
0123456789012345678901234567890123456789 foo
is accepted. Though we do put extra bytes like this into
some pseudorefs (e.g., FETCH_HEAD), we don't typically do so
with HEAD. We could tighten this up by using parse_oid_hex(),
like:
if (!parse_oid_hex(buffer, &oid, &end) &&
*end++ == '\n' && *end == '\0')
return 0;
But we're probably better to remain on the loose side. We're
just checking here for a plausible-looking repository
directory, so heuristics are acceptable (if we really want
to be meticulous, we should use the actual ref code to parse
HEAD).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since the previous commit guarantees that our symref buffer
is NUL-terminated, we can just use skip_prefix() and friends
to parse it. This is shorter and saves us having to deal
with magic numbers and keeping the "len" counter up to date.
While we're at it, let's name the rather obscure "buf" to
"refname", since that is the thing we are parsing with it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we are checking to see if we have a git repo, we peek
into the HEAD file and see if it's a plausible symlink,
symref, or detached HEAD.
For the latter two, we read the contents with read_in_full(),
which means they aren't NUL-terminated. The symref check is
careful to respect the length we got, but the sha1 check
will happily parse up to 40 bytes, even if we read fewer.
E.g.,:
echo 1234 >.git/HEAD
git rev-parse
will parse 36 uninitialized bytes from our stack buffer.
This isn't a big deal in practice. Our buffer is 256 bytes,
so we know we'll never read outside of it. The worst case is
that the uninitialized bytes look like valid hex, and we
claim a bogus HEAD file is valid. The chances of this
happening randomly are quite slim, but let's be careful.
One option would be to check that "len == 41" before feeding
the buffer to get_sha1_hex(). But we'd like to eventually
prepare for a world with variable-length hashes. Let's
NUL-terminate as soon as we've read the buffer (we already
even leave a spare byte to do so!). That fixes this problem
without depending on the size of an object id.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We reject hostnames that start with a dash because they may
be confused for command-line options. Let's factor out that
notion into a helper function, as we'll use it in more
places. And while it's simple now, it's not clear if some
systems might need more complex logic to handle all 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>
Introduce 'repo_worktree_path' and 'strbuf_repo_worktree_path' which
take a repository struct and constructs a path relative to the
repository's worktree.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce 'repo_git_path' and 'strbuf_repo_git_path' which take a
repository struct and constructs a path into the repository's git
directory.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git_path is a convenience function that usually produces a string
$GIT_DIR/<path>. Since v2.5.0-rc0~143^2~35 (git_path(): be aware of
file relocation in $GIT_DIR, 2014-11-30), as a side benefit callers
get support for path relocation variables like $GIT_OBJECT_DIRECTORY:
- git_path("index") is $GIT_INDEX_FILE when set
- git_path("info/grafts") is $GIT_GRAFTS_FILE when set
- git_path("objects/<foo>") is $GIT_OBJECT_DIRECTORY/<foo> when set
- git_path("hooks/<foo>") is <foo> under core.hookspath when set
- git_path("refs/<foo>") etc (see path.c::common_list) is relative
to $GIT_COMMON_DIR instead of $GIT_DIR
worktree_git_path, by comparison, is designed to resolve files in a
specific worktree's git dir. Unfortunately, it shares code with
git_path and performs the same relocation. The result is that paths
that are meant to be relative to the specified worktree's git dir end
up replaced by paths from environment variables within the current git
dir.
Luckily, no current callers pass such arguments. The relocation was
noticed when testing the result of merging two patches under review,
one of which introduces a caller:
* The first patch made git prune check the index file in each
worktree's git dir (using worktree_git_path(wt, "index")) for
objects not to prune. This would trigger the unwanted relocation
when GIT_INDEX_FILE is set, causing objects reachable from the
index to be pruned.
* The second patch simplified the relocation logic for index,
info/grafts, objects, and hooks to happen unconditionally instead of
based on whether environment or configuration variables are set.
This caused the relocation to trigger even when GIT_INDEX_FILE is
not set.
[jn: rewrote commit message; skipping all relocation instead of just
GIT_INDEX_FILE]
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In preparation to adding 'git_path' like functions which operate on a
'struct repository' convert 'do_git_path' to take a 'struct repository'.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of passing in 'NULL' and having 'update_common_dir()' query for
the commondir, have the callers of 'update_common_dir()' be responsible
for providing the commondir.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move all path related declarations from cache.h to a new path.h header
file. This makes cache.h smaller and makes it easier to add new path
related functions.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Migrate 'git_dir', 'git_common_dir', 'git_object_dir', 'git_index_file',
'git_graft_file', and 'namespace' to be stored in 'the_repository'.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
$GIT_DIR may in some cases be normalized with all symlinks resolved
while "gitdir" path expansion in the pattern does not receive the
same treatment, leading to incorrect mismatch. This has been fixed.
* nd/conditional-config-include:
config: resolve symlinks in conditional include's patterns
path.c: and an option to call real_path() in expand_user_path()
The "submodule" specific field in the ref_store structure is
replaced with a more generic "gitdir" that can later be used also
when dealing with ref_store that represents the set of refs visible
from the other worktrees.
* nd/files-backend-git-dir: (28 commits)
refs.h: add a note about sorting order of for_each_ref_*
t1406: new tests for submodule ref store
t1405: some basic tests on main ref store
t/helper: add test-ref-store to test ref-store functions
refs: delete pack_refs() in favor of refs_pack_refs()
files-backend: avoid ref api targeting main ref store
refs: new transaction related ref-store api
refs: add new ref-store api
refs: rename get_ref_store() to get_submodule_ref_store() and make it public
files-backend: replace submodule_allowed check in files_downcast()
refs: move submodule code out of files-backend.c
path.c: move some code out of strbuf_git_path_submodule()
refs.c: make get_main_ref_store() public and use it
refs.c: kill register_ref_store(), add register_submodule_ref_store()
refs.c: flatten get_ref_store() a bit
refs: rename lookup_ref_store() to lookup_submodule_ref_store()
refs.c: introduce get_main_ref_store()
files-backend: remove the use of git_path()
files-backend: add and use files_ref_path()
files-backend: add and use files_reflog_path()
...
In the next patch we need the ability to expand '~' to
real_path($HOME). But we can't do that from outside because '~' is part
of a pattern, not a true path. Add an option to expand_user_path() to do
so.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
refs is learning to avoid path rewriting that is done by
strbuf_git_path_submodule(). Factor out this code so it could be reused
by refs_* functions.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We already have xdg_config_home to format paths relative to
XDG_CONFIG_HOME. Let's provide a similar function xdg_cache_home to do
the same for paths relative to XDG_CACHE_HOME.
Signed-off-by: Devin Lehmacher <lehmacdj@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A pathname that begins with "//" or "\\" on Windows is special but
path normalization logic was unaware of it.
* js/normalize-path-copy-ceil:
normalize_path_copy(): fix pushing to //server/share/dir on Windows
A pathname that begins with "//" or "\\" on Windows is special but
path normalization logic was unaware of it.
* js/normalize-path-copy-ceil:
normalize_path_copy(): fix pushing to //server/share/dir on Windows
normalize_path_copy() is not prepared to keep the double-slash of a
//server/share/dir kind of path, but treats it like a regular POSIX
style path and transforms it to /server/share/dir.
The bug manifests when 'git push //server/share/dir master' is run,
because tmp_objdir_add_as_alternate() uses the path in normalized
form when it registers the quarantine object database via
link_alt_odb_entries(). Needless to say that the directory cannot be
accessed using the wrongly normalized path.
Fix it by skipping all of the root part, not just a potential drive
prefix. offset_1st_component takes care of this, see the
implementation in compat/mingw.c::mingw_offset_1st_component().
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code that we have used for the past 10+ years to cycle
4-element ring buffers turns out to be not quite portable in
theoretical world.
* rs/ring-buffer-wraparound:
hex: make wraparound of the index into ring-buffer explicit
Overflow is defined for unsigned integers, but not for signed ones.
We could make the ring-buffer index in sha1_to_hex() and
get_pathname() unsigned to be on the safe side to resolve this, but
let's make it explicit that we are wrapping around at whatever the
number of elements the ring-buffer has. The compiler is smart enough
to turn modulus into bitmask for these codepaths that use
ring-buffers of a size that is a power of 2.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "git diff --submodule={short,log}" mechanism has been enhanced
to allow "--submodule=diff" to show the patch between the submodule
commits bound to the superproject.
* jk/diff-submodule-diff-inline:
diff: teach diff to display submodule difference with an inline diff
submodule: refactor show_submodule_summary with helper function
submodule: convert show_submodule_summary to use struct object_id *
allow do_submodule_path to work even if submodule isn't checked out
diff: prepare for additional submodule formats
graph: add support for --line-prefix on all graph-aware output
diff.c: remove output_prefix_length field
cache: add empty_tree_oid object and helper function
Currently, do_submodule_path will attempt locating the .git directory by
using read_gitfile on <path>/.git. If this fails it just assumes the
<path>/.git is actually a git directory.
This is good because it allows for handling submodules which were cloned
in a regular manner first before being added to the superproject.
Unfortunately this fails if the <path> is not actually checked out any
longer, such as by removing the directory.
Fix this by checking if the directory we found is actually a gitdir. In
the case it is not, attempt to lookup the submodule configuration and
find the name of where it is stored in the .git/modules/ directory of
the superproject.
If we can't locate the submodule configuration, this might occur because
for example a submodule gitlink was added but the corresponding
.gitmodules file was not properly updated. A die() here would not be
pleasant to the users of submodule diff formats, so instead, modify
do_submodule_path() to return an error code:
- git_pathdup_submodule() returns NULL when we fail to find a path.
- strbuf_git_path_submodule() propagates the error code to the caller.
Modify the callers of these functions to check the error code and fail
properly. This ensures we don't attempt to use a bad path that doesn't
match the corresponding submodule.
Because this change fixes add_submodule_odb() to work even if the
submodule is not checked out, update the wording of the submodule log
diff format to correctly display that the submodule is "not initialized"
instead of "not checked out"
Add tests to ensure this change works as expected.
Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git rev-parse --git-path hooks/<hook>" learned to take
core.hooksPath configuration variable (introduced during 2.9 cycle)
into account.
* ab/hooks:
rev-parse: respect core.hooksPath in --git-path
The idea of the --git-path option is not only to avoid having to
prefix paths with the output of --git-dir all the time, but also to
respect overrides for specific common paths inside the .git directory
(e.g. `git rev-parse --git-path objects` will report the value of the
environment variable GIT_OBJECT_DIRECTORY, if set).
When introducing the core.hooksPath setting, we forgot to adjust
git_path() accordingly. This patch fixes that.
While at it, revert the special-casing of core.hooksPath in
run-command.c, as it is now no longer needed.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code cleanup.
* rs/use-strbuf-addbuf:
strbuf: avoid calling strbuf_grow() twice in strbuf_addbuf()
use strbuf_addbuf() for appending a strbuf to another
Code cleanup.
* rs/use-strbuf-addbuf:
strbuf: avoid calling strbuf_grow() twice in strbuf_addbuf()
use strbuf_addbuf() for appending a strbuf to another
Use strbuf_addbuf() where possible; it's shorter and more efficient.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The experimental "multiple worktree" feature gains more safety to
forbid operations on a branch that is checked out or being actively
worked on elsewhere, by noticing that e.g. it is being rebased.
* nd/worktree-various-heads:
branch: do not rename a branch under bisect or rebase
worktree.c: check whether branch is bisected in another worktree
wt-status.c: split bisect detection out of wt_status_get_state()
worktree.c: check whether branch is rebased in another worktree
worktree.c: avoid referencing to worktrees[i] multiple times
wt-status.c: make wt_status_check_rebase() work on any worktree
wt-status.c: split rebase detection out of wt_status_get_state()
path.c: refactor and add worktree_git_path()
worktree.c: mark current worktree
worktree.c: make find_shared_symref() return struct worktree *
worktree.c: store "id" instead of "git_dir"
path.c: add git_common_path() and strbuf_git_common_path()
dir.c: rename str(n)cmp_icase to fspath(n)cmp
Many instances of duplicate words (e.g. "the the path") and
a few typoes are fixed, originally in multiple patches.
wildmatch: fix duplicate words of "the"
t: fix duplicate words of "output"
transport-helper: fix duplicate words of "read"
Git.pm: fix duplicate words of "return"
path: fix duplicate words of "look"
pack-protocol.txt: fix duplicate words of "the"
precompose-utf8: fix typo of "sequences"
split-index: fix typo
worktree.c: fix typo
remote-ext: fix typo
utf8: fix duplicate words of "the"
git-cvsserver: fix duplicate words
Signed-off-by: Li Peng <lip@dtdream.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The repository set-up sequence has been streamlined (the biggest
change is that there is no longer git_config_early()), so that we
do not attempt to look into refs/* when we know we do not have a
Git repository.
* jk/check-repository-format:
verify_repository_format: mark messages for translation
setup: drop repository_format_version global
setup: unify repository version callbacks
init: use setup.c's repo version verification
setup: refactor repo format reading and verification
config: drop git_config_early
check_repository_format_gently: stop using git_config_early
lazily load core.sharedrepository
wrap shared_repository global in get/set accessors
setup: document check_repository_format()
do_git_path(), which is the common code for all git_path* functions, is
modified to take a worktree struct and can produce paths for any
worktree.
worktree_git_path() is the first function that makes use of this. It can
be used to write code that can examine any worktree. For example,
wt_status_get_state() will be converted using this to take
am/rebase/... state of any worktree.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These are mostly convenient functions to reduce code duplication. Most
of the time, we should be able to get by with git_path() which handles
$GIT_COMMON_DIR internally. However there are a few cases where we need
to construct paths manually, for example some paths from a specific
worktree. These functions will enable that.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The repository set-up sequence has been streamlined (the biggest
change is that there is no longer git_config_early()), so that we
do not attempt to look into refs/* when we know we do not have a
Git repository.
* jk/check-repository-format:
verify_repository_format: mark messages for translation
setup: drop repository_format_version global
setup: unify repository version callbacks
init: use setup.c's repo version verification
setup: refactor repo format reading and verification
config: drop git_config_early
check_repository_format_gently: stop using git_config_early
lazily load core.sharedrepository
wrap shared_repository global in get/set accessors
setup: document check_repository_format()
On Windows, the backslash is the native directory separator, but all
supported Windows versions also accept the forward slash in most
circumstances.
Our tests expect forward slashes.
Relative paths are generated by Git using forward slashes.
So let's try to be consistent and use forward slashes in the $HOME part
of the paths reported by `git config --show-origin`, too.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It would be useful to control access to the global
shared_repository, so that we can lazily load its config.
The first step to doing so is to make sure all access
goes through a set of functions.
This step is purely mechanical, and should result in no
change of behavior.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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
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
Junio noticed that there is an implicit assumption in pretty much
all the code calling has_dos_drive_prefix(): it forces all of its
callsites to hardcode the knowledge that the DOS drive prefix is
always two bytes long.
While this assumption is pretty safe, we can still make the code
more readable and less error-prone by introducing a function that
skips the DOS drive prefix safely.
While at it, we change the has_dos_drive_prefix() return value: it
now returns the number of bytes to be skipped if there is a DOS
drive prefix.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code preparation for pluggable ref backends.
* dt/refs-backend-pre-vtable:
refs: break out ref conflict checks
files_log_ref_write: new function
initdb: make safe_create_dir public
refs: split filesystem-based refs code into a new file
refs/refs-internal.h: new header file
refname_is_safe(): improve docstring
pack_if_possible_fn(): use ref_type() instead of is_per_worktree_ref()
copy_msg(): rename to copy_reflog_msg()
verify_refname_available(): new function
verify_refname_available(): rename function
Having a leftover .idx file without corresponding .pack file in
the repository hurts performance; "git gc" learned to prune them.
We may want to do the same for .bitmap (and notice but not prune
.keep) without corresponding .pack, but that can be a separate
topic.
* dk/gc-idx-wo-pack:
gc: remove garbage .idx files from pack dir
t5304: test cleaning pack garbage
prepare_packed_git(): refactor garbage reporting in pack directory
Having a leftover .idx file without corresponding .pack file in
the repository hurts performance; "git gc" learned to prune them.
* dk/gc-idx-wo-pack:
gc: remove garbage .idx files from pack dir
t5304: test cleaning pack garbage
prepare_packed_git(): refactor garbage reporting in pack directory
Soon we will want to create initdb functions for ref backends, and
code from initdb that calls this function needs to move into the files
backend. So this function needs to be public.
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
It was not possible to use a repository-lookalike created by "git
worktree add" as a local source of "git clone".
* nd/clone-linked-checkout:
clone: better error when --reference is a linked checkout
clone: allow --local from a linked checkout
enter_repo: allow .git files in strict mode
enter_repo: avoid duplicating logic, use is_git_directory() instead
t0002: add test for enter_repo(), non-strict mode
path.c: delete an extra space
The submodule code has been taught to work better with separate
work trees created via "git worktree add".
* mk/submodule-gitdir-path:
path: implement common_dir handling in git_pathdup_submodule()
submodule refactor: use strbuf_git_path_submodule() in add_submodule_odb()
Many allocations that is manually counted (correctly) that are
followed by strcpy/sprintf have been replaced with a less error
prone constructs such as xstrfmt.
Macintosh-specific breakage was noticed and corrected in this
reroll.
* jk/war-on-sprintf: (70 commits)
name-rev: use strip_suffix to avoid magic numbers
use strbuf_complete to conditionally append slash
fsck: use for_each_loose_file_in_objdir
Makefile: drop D_INO_IN_DIRENT build knob
fsck: drop inode-sorting code
convert strncpy to memcpy
notes: document length of fanout path with a constant
color: add color_set helper for copying raw colors
prefer memcpy to strcpy
help: clean up kfmclient munging
receive-pack: simplify keep_arg computation
avoid sprintf and strcpy with flex arrays
use alloc_ref rather than hand-allocating "struct ref"
color: add overflow checks for parsing colors
drop strcpy in favor of raw sha1_to_hex
use sha1_to_hex_r() instead of strcpy
daemon: use cld->env_array when re-spawning
stat_tracking_info: convert to argv_array
http-push: use an argv_array for setup_revisions
fetch-pack: use argv_array for index-pack / unpack-objects
...
The normalize_ceiling_entry() function does not muck with the end
of the path it accepts, and the real world callers do rely on that,
but a test insisted that the function drops a trailing slash.
* rd/test-path-utils:
test-path-utils.c: remove incorrect assumption
It was not possible to use a repository-lookalike created by "git
worktree add" as a local source of "git clone".
* nd/clone-linked-checkout:
clone: better error when --reference is a linked checkout
clone: allow --local from a linked checkout
enter_repo: allow .git files in strict mode
enter_repo: avoid duplicating logic, use is_git_directory() instead
t0002: add test for enter_repo(), non-strict mode
path.c: delete an extra space
The submodule code has been taught to work better with separate
work trees created via "git worktree add".
* mk/submodule-gitdir-path:
path: implement common_dir handling in git_pathdup_submodule()
submodule refactor: use strbuf_git_path_submodule() in add_submodule_odb()
In normalize_ceiling_entry(), we test that normalized paths end with
slash, *unless* the path to be normalized was already the root
directory.
However, normalize_path_copy() does not even enforce this condition.
Even worse: on Windows, the root directory gets translated into a
Windows directory by the Bash before being passed to `git.exe` (or
`test-path-utils.exe`), which means that we cannot even know whether
the path that was passed to us was the root directory to begin with.
This issue has already caused endless hours of trying to "fix" the
MSYS2 runtime, only to break other things due to MSYS2 ensuring that
the converted path maintains the same state as the input path with
respect to any final '/'.
So let's just forget about this test. It is non-essential to Git's
operation, anyway.
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Ray Donnelly <mingw.android@gmail.com>
When working with paths in strbufs, we frequently want to
ensure that a directory contains a trailing slash before
appending to it. We can shorten this code (and make the
intent more obvious) by calling strbuf_complete.
Most of these cases are trivially identical conversions, but
there are two things to note:
- in a few cases we did not check that the strbuf is
non-empty (which would lead to an out-of-bounds memory
access). These were generally not triggerable in
practice, either from earlier assertions, or typically
because we would have just fed the strbuf to opendir(),
which would choke on an empty path.
- in a few cases we indexed the buffer with "original_len"
or similar, rather than the current sb->len, and it is
not immediately obvious from the diff that they are the
same. In all of these cases, I manually verified that
the strbuf does not change between the assignment and
the strbuf_complete call.
This does not convert cases which look like:
if (sb->len && !is_dir_sep(sb->buf[sb->len - 1]))
strbuf_addch(sb, '/');
as those are obviously semantically different. Some of these
cases arguably should be doing that, but that is out of
scope for this change, which aims purely for cleanup with no
behavior change (and at least it will make such sites easier
to find and examine in the future, as we can grep for
strbuf_complete).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function strcpy's directly into a PATH_MAX-sized
buffer. There's only one caller, which feeds the git_dir into
it, so it's not easy to trigger in practice (even if you fed
a large $GIT_DIR through the environment or .git file, it
would have to actually exist and be accessible on the
filesystem to get to this point). We can fix it by moving to
a strbuf.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We use two PATH_MAX-sized buffers to represent the repo
path, and must make sure not to overflow them. We do take
care to check the lengths, but the logic is rather hard to
follow, as we use several magic numbers (e.g., "PATH_MAX -
10"). And in fact you _can_ overflow the buffer if you have
a ".git" file with an extremely long path in it.
By switching to strbufs, these problems all go away. We do,
however, retain the check that the initial input we get is
no larger than PATH_MAX. This function is an entry point for
untrusted repo names from the network, and it's a good idea
to keep a sanity check (both to avoid allocating arbitrary
amounts of memory, and also as a layer of defense against
any downstream users of the names).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Strict mode is about not guessing where .git is. If the user points to a
.git file, we know exactly where the target .git dir will be. This makes
it possible to serve .git files as repository on the server side.
This may be needed even in local clone case because transport.c code
uses upload-pack for fetching remote refs. But right now the
clone/transport code goes with non-strict.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It matters for linked checkouts where 'refs' directory won't be
available in $GIT_DIR. is_git_directory() knows about $GIT_COMMON_DIR
and can handle this case.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If you have a function that uses git_path a lot, but would
prefer to avoid the static buffers, it's useful to keep a
single scratch buffer locally and reuse it for each call.
You used to be able to do this with git_snpath:
char buf[PATH_MAX];
foo(git_snpath(buf, sizeof(buf), "foo"));
bar(git_snpath(buf, sizeof(buf), "bar"));
but since 1a83c24, git_snpath has been replaced with
strbuf_git_path. This is good, because it removes the
arbitrary PATH_MAX limit. But using strbuf_git_path is more
awkward for two reasons:
1. It adds to the buffer, rather than replacing it. This
is consistent with other strbuf functions, but makes
reuse of a single buffer more tedious.
2. It doesn't return the buffer, so you can't format
as part of a function's arguments.
The new git_path_buf solves both of these, so you can use it
like:
struct strbuf buf = STRBUF_INIT;
foo(git_path_buf(&buf, "foo"));
bar(git_path_buf(&buf, "bar"));
strbuf_release(&buf);
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When submodule is a linked worktree, "git diff --submodule" and other
calls which directly access the submodule's object database do not correctly
calculate its path. Fix it by changing the git_pathdup_submodule() behavior,
to use either common or per-worktree directory.
Do it similarly as for parent repository, but ignore the GIT_COMMON_DIR
environment variable, because it would mean common directory for the parent
repository and does not make sense for submodule.
Also add test for functionality which uses this call.
Signed-off-by: Max Kirillov <max@max630.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We need the place we stick refs for bisects in progress to not be
shared between worktrees. So we make the refs/bisect/ hierarchy
per-worktree.
The is_per_worktree_ref function and associated docs learn that
refs/bisect/ is per-worktree, as does the git_path code in path.c
The ref-packing functions learn that per-worktree refs should not be
packed (since packed-refs is common rather than per-worktree).
Since refs/bisect is per-worktree, logs/refs/bisect should be too.
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of a linear search over common_list to check whether
a path is common, use a trie. The trie search operates on
path prefixes, and handles excludes.
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of common_list having formatting like ! and /, use a struct to
hold common_list data in a structured form.
We don't use 'exclude' yet; instead, we keep the old codepath that
handles info/sparse-checkout and logs/HEAD. Later, we will use exclude.
[jc: with "make common_list[] static" clean-up from Ramsay squashed in]
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The hook to report "garbage" files in $GIT_OBJECT_DIRECTORY/pack/
could be generic but is too specific to count-object's needs.
Move the part to produce human-readable messages to count-objects,
and refine the interface to callback with the "bits" with values
defined in the cache.h header file, so that other callers (e.g.
prune) can later use the same mechanism to enumerate different
kinds of garbage files and do something intelligent about them,
other than reporting in textual messages.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
One of the most common uses of git_path() is to pass a
constant, like git_path("MERGE_MSG"). This has two
drawbacks:
1. The return value is a static buffer, and the lifetime
is dependent on other calls to git_path, etc.
2. There's no compile-time checking of the pathname. This
is OK for a one-off (after all, we have to spell it
correctly at least once), but many of these constant
strings appear throughout the code.
This patch introduces a series of functions to "memoize"
these strings, which are essentially globals for the
lifetime of the program. We compute the value once, take
ownership of the buffer, and return the cached value for
subsequent calls. cache.h provides a helper macro for
defining these functions as one-liners, and defines a few
common ones for global use.
Using a macro is a little bit gross, but it does nicely
document the purpose of the functions. If we need to touch
them all later (e.g., because we learned how to change the
git_dir variable at runtime, and need to invalidate all of
the stored values), it will be much easier to have the
complete list.
Note that the shared-global functions have separate, manual
declarations. We could do something clever with the macros
(e.g., expand it to a declaration in some places, and a
declaration _and_ a definition in path.c). But there aren't
that many, and it's probably better to stay away from
too-magical macros.
Likewise, if we abandon the C preprocessor in favor of
generating these with a script, we could get much fancier.
E.g., normalizing "FOO/BAR-BAZ" into "git_path_foo_bar_baz".
But the small amount of saved typing is probably not worth
the resulting confusion to readers who want to grep for the
function's definition.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are no callers of the slightly-dangerous static-buffer
git_path_submodule left. Let's drop it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git_path function has "git_pathdup" and
"strbuf_git_path" variants, but git_submodule_path only
comes in the dangerous, static-buffer variant. That makes
refactoring callers to use the safer functions hard (since
they don't exist).
Since we're already using a strbuf behind the scenes, it's
easy to expose all three of these interfaces with thin
wrappers.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code clean-up for xdg configuration path support.
* pt/xdg-config-path:
path.c: remove home_config_paths()
git-config: replace use of home_config_paths()
git-commit: replace use of home_config_paths()
credential-store.c: replace home_config_paths() with xdg_config_home()
dir.c: replace home_config_paths() with xdg_config_home()
attr.c: replace home_config_paths() with xdg_config_home()
path.c: implement xdg_config_home()
A replacement for contrib/workdir/git-new-workdir that does not
rely on symbolic links and make sharing of objects and refs safer
by making the borrowee and borrowers aware of each other.
* nd/multiple-work-trees: (41 commits)
prune --worktrees: fix expire vs worktree existence condition
t1501: fix test with split index
t2026: fix broken &&-chain
t2026 needs procondition SANITY
git-checkout.txt: a note about multiple checkout support for submodules
checkout: add --ignore-other-wortrees
checkout: pass whole struct to parse_branchname_arg instead of individual flags
git-common-dir: make "modules/" per-working-directory directory
checkout: do not fail if target is an empty directory
t2025: add a test to make sure grafts is working from a linked checkout
checkout: don't require a work tree when checking out into a new one
git_path(): keep "info/sparse-checkout" per work-tree
count-objects: report unused files in $GIT_DIR/worktrees/...
gc: support prune --worktrees
gc: factor out gc.pruneexpire parsing code
gc: style change -- no SP before closing parenthesis
checkout: clean up half-prepared directories in --to mode
checkout: reject if the branch is already checked out elsewhere
prune: strategies for linked checkouts
checkout: support checking out into a new working directory
...
home_config_paths() combines distinct functionality already implemented
by expand_user_path() and xdg_config_home(), and it also hard-codes the
path ~/.gitconfig, which makes it unsuitable to use for other home
config file paths. Since its use will just add unnecessary complexity to
the code, remove it.
Signed-off-by: Paul Tan <pyokagan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The XDG base dir spec[1] specifies that configuration files be stored in
a subdirectory in $XDG_CONFIG_HOME. To construct such a configuration
file path, home_config_paths() can be used. However, home_config_paths()
combines distinct functionality:
1. Retrieve the home git config file path ~/.gitconfig
2. Construct the XDG config path of the file specified by `file`.
This function was introduced in commit 21cf3227 ("read (but not write)
from $XDG_CONFIG_HOME/git/config file"). While the intention of the
function was to allow the home directory configuration file path and the
xdg directory configuration file path to be retrieved with one function
call, the hard-coding of the path ~/.gitconfig prevents it from being
used for other configuration files. Furthermore, retrieving a file path
relative to the user's home directory can be done with
expand_user_path(). Hence, it can be seen that home_config_paths()
introduces unnecessary complexity, especially if a user just wants to
retrieve the xdg config file path.
As such, implement a simpler function xdg_config_home() for constructing
the XDG base dir spec configuration file path. This function, together
with expand_user_path(), can replace all uses of home_config_paths().
[1] http://standards.freedesktop.org/basedir-spec/basedir-spec-0.7.html
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Paul Tan <pyokagan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
