git rev-parse has several options which print various paths. Some of
these paths are printed relative to the current working directory, and
some are absolute.
Normally, this is not a problem, but there are times when one wants
paths entirely in one format or another. This can be done trivially if
the paths are canonical, but canonicalizing paths is not possible on
some shell scripting environments which lack realpath(1) and also in Go,
which lacks functions that properly canonicalize paths on Windows.
To help out the scripter, let's provide an option which turns most of
the paths printed by git rev-parse to be either relative to the current
working directory or absolute and canonical. Document which options are
affected and which are not so that users are not confused.
This approach is cleaner and tidier than providing duplicates of
existing options which are either relative or absolute.
Note that if the user needs both forms, it is possible to pass an
additional option in the middle of the command line which changes the
behavior of subsequent operations.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We taught rev-list a new way to separate options from revisions in
19e8789b23 (revision: allow --end-of-options to end option parsing,
2019-08-06), but rev-parse uses its own parser. It should know about
--end-of-options not only for consistency, but because it may be
presented with similarly ambiguous cases. E.g., if a caller does:
git rev-parse "$rev" -- "$path"
to parse an untrusted input, then it will get confused if $rev contains
an option-like string like "--local-env-vars". Or even "--not-real",
which we'd keep as an option to pass along to rev-list.
Or even more importantly:
git rev-parse --verify "$rev"
can be confused by options, even though its purpose is safely parsing
untrusted input. On the plus side, it will always fail the --verify
part, as it will not have parsed a revision, so the caller will
generally "fail closed" rather than continue to use the untrusted
string. But it will still trigger whatever option was in "$rev"; this
should be mostly harmless, since rev-parse options are all read-only,
but I didn't carefully audit all paths.
This patch lets callers write:
git rev-parse --end-of-options "$rev" -- "$path"
and:
git rev-parse --verify --end-of-options "$rev"
which will both treat "$rev" always as a revision parameter. The latter
is a bit clunky. It would be nicer if we had defined "--verify" to
require that its next argument be the revision. But we have not
historically done so, and:
git rev-parse --verify -q "$rev"
does currently work. I added a test here to confirm that we didn't break
that.
A few implementation notes:
- We don't document --end-of-options explicitly in commands, but rather
in gitcli(7). So I didn't give it its own section in git-rev-parse(1).
But I did call it out specifically in the --verify section, and
include it in the examples, which should show best practices.
- We don't have to re-indent the main option-parsing block, because we
can combine our "did we see end of options" check with "does it start
with a dash". The exception is the pre-setup options, which need
their own block.
- We do however have to pull the "--" parsing out of the "does it start
with dash" block, because we want to parse it even if we've seen
--end-of-options.
- We'll leave "--end-of-options" in the output. This is probably not
technically necessary, as a careful caller will do:
git rev-parse --end-of-options $revs -- $paths
and anything in $revs will be resolved to an object id. However, it
does help a slightly less careful caller like:
git rev-parse --end-of-options $revs_or_paths
where a path "--foo" will remain in the output as long as it also
exists on disk. In that case, it's helpful to retain --end-of-options
to get passed along to rev-list, s it would otherwise see just
"--foo".
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The option-parsing loop of rev-parse checks whether the first character
of an arg is "-". If so, then it enters a series of conditionals
checking for individual options. But some options are inexplicably
outside of that outer conditional.
This doesn't produce the wrong behavior; the conditional is actually
redundant with the individual option checks, and it's really only its
fallback "continue" that we care about. But we should at least be
consistent.
One obvious alternative is that we could get rid of the conditional
entirely. But we'll be using the extra block it provides in the next
patch.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Because of the order in which we check options in rev-parse, there are a
few options we accept even after a "--". This is wrong, because the
whole point of "--" is to say "everything after here is a path". Let's
move the "did we see a dashdash" check (it's called "as_is" in the code)
to the top of the parsing loop.
Note there is one subtlety here. The options are ordered so that some
are checked before we even see if we're in a repository (they continue
the loop, and if we get past a certain point, then we do the repository
setup). By moving the as_is check higher, it's also in that "before
setup" section, even though it might look at the repository via
verify_filename(). However, this works out: we'd never set as_is until
we parse "--", and we don't parse that until after doing the setup.
An alternative here to avoid the subtlety is to put the as_is check at
the top of the post-setup options. But then every pre-setup option would
have to remember to check "if (!as_is && !strcmp(...))". So while this
is a bit magical, it's harder for future code to get wrong.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a user checks out the upstream branch of HEAD, the upstream branch
not being a local branch, and then runs "git status", like this:
git clone $URL client
cd client
git checkout @{u}
git status
no status is printed, but instead an error message:
fatal: HEAD does not point to a branch
(This error message when running "git branch" persists even after
checking out other things - it only stops after checking out a branch.)
This is because "git status" reads the reflog when determining the "HEAD
detached" message, and thus attempts to DWIM "@{u}", but that doesn't
work because HEAD no longer points to a branch.
Therefore, when calculating the status of a worktree, tolerate dangling
marks. This is done by adding an additional parameter to
dwim_ref() and repo_dwim_ref().
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are many functions in commit.h that are more related to shallow
repositories than they are to any sort of generic commit machinery.
Likely this began when there were only a few shallow-related functions,
and commit.h seemed a reasonable enough place to put them.
But, now there are a good number of shallow-related functions, and
placing them all in 'commit.h' doesn't make sense.
This patch extracts a 'shallow.h', which takes all of the declarations
from 'commit.h' for functions which already exist in 'shallow.c'. We
will bring the remaining shallow-related functions defined in 'commit.c'
in a subsequent patch.
For now, move only the ones that already are implemented in 'shallow.c',
and update the necessary includes.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Together with the previous commits, this commit fully fixes the problem
of using shared buffer for `real_path()` in `get_superproject_working_tree()`.
Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Returning a shared buffer invites very subtle bugs due to reentrancy or
multi-threading, as demonstrated by the previous patch.
There was an unfinished effort to abolish this [1].
Let's finally rid of `real_path()`, using `strbuf_realpath()` instead.
This patch uses a local `strbuf` for most places where `real_path()` was
previously called.
However, two places return the value of `real_path()` to the caller. For
them, a `static` local `strbuf` was added, effectively pushing the
problem one level higher:
read_gitfile_gently()
get_superproject_working_tree()
[1] https://lore.kernel.org/git/1480964316-99305-1-git-send-email-bmwill@google.com/
Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Ever since it was introduced in 7cceca5ccc (Add 'git rev-parse
--show-toplevel' option., 2010-01-12), the --show-toplevel option has
treated a missing working tree as a quiet success: it neither prints a
toplevel path, but nor does it report any kind of error.
While a caller could distinguish this case by looking for an empty
response, the behavior is rather confusing. We're better off complaining
that there is no working tree, as other internal commands would do in
similar cases (e.g., "git status" or any builtin with NEED_WORK_TREE set
would just die()). So let's do the same here.
While we're at it, let's clarify the documentation and add some tests,
both for the new behavior and for the more mundane case (which was not
covered).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add an option to print the object format used for input, output, or
storage. This allows shell scripts to discover the hash algorithm in
use.
Since the transition plan allows for multiple input algorithms, document
that we may provide multiple results for input, and the format that the
results may take. While we don't support this now, documenting it early
means that script authors can future-proof their scripts for when we do.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Switch several hard-coded uses of the constant 40 to references to
the_hash_algo.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
By default, index compat macros are off from now on, because they
could hide the_index dependency.
Only those in builtin can use it.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This kills the_index dependency in get_oid_with_context() but for
get_oid() and friends, they still assume the_repository (which also
means the_index).
Unfortunately the widespread use of get_oid() will make it hard to
make the conversion now. We probably will add repo_get_oid() at some
point and limit the use of get_oid() in builtin/ instead of forcing
all get_oid() call sites to carry struct repository.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git rev-parse --exclude=* --branches --branches" (i.e. first
saying "add only things that do not match '*' out of all branches"
and then adding all branches, without any exclusion this time")
worked as expected, but "--exclude=* --all --all" did not work the
same way, which has been fixed.
* ag/rev-parse-all-exclude-fix:
rev-parse: clear --exclude list after 'git rev-parse --all'
Commit [1] added the --exclude option to revision.c. The --all,
--branches, --tags, --remotes, and --glob options clear the exclude
list. Shortly therafter, commit [2] added the same to 'git rev-parse',
but without clearing the exclude list for the --all option.
[1] e7b432c52 ("revision: introduce --exclude=<glob> to tame wildcards", 2013-08-30)
[2] 9dc01bf06 ("rev-parse: introduce --exclude=<glob> to tame wildcards", 2013-11-01)
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These methods are now declared in commit-reach.h. Remove them from
commit.h and add new include statements in all files that require these
declarations.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a repository argument to allow callers of lookup_commit_reference
to be more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.
As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git rev-parse Y..." etc. misbehaved when given endpoints were
not committishes.
* en/rev-parse-invalid-range:
rev-parse: check lookup'ed commit references for NULL
Commits 2122f8b963 ("rev-parse: Add support for the ^! and ^@ syntax",
2008-07-26) and 3dd4e7320d ("Teach rev-parse the ... syntax.", 2006-07-04)
taught rev-parse new syntax, and used lookup_commit_reference() as part of
their logic. Neither usage checked the returned commit to see if it was
non-NULL before using it. Check for NULL and ensure an appropriate error
is reported to the user.
Reported by Florian Weimer and Todd Zullinger.
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a repository argument to allow callers of is_repository_shallow
to be more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.
As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the base_sha1 member of struct split_index to use struct
object_id and rename it base_oid. Include cache.h to make the structure
visible.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert find_unique_abbrev and find_unique_abbrev_r to each take a
pointer to struct object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename C++ keyword in order to bring the codebase closer to being able
to be compiled with a C++ compiler.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
No caller passes anything but "0" for this parameter, which
requests that the function ignore it completely. In fact, in
all of history there was only one such caller, and it went
away in 7f51f8bc2b (alias: use run_command api to execute
aliases, 2011-01-07).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
All of the callers of these functions just pass the hash member of a
struct object_id, so convert them to use a pointer to struct object_id
directly. Insert a check for NULL in expand_ref on a temporary basis;
this check can be removed when resolve_ref_unsafe is converted as well.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Recent versions of "git rev-parse --parseopt" did not parse the
option specification that does not have the optional flags (*=?!)
correctly, which has been corrected.
* bc/rev-parse-parseopt-fix:
parse-options: only insert newline in help text if needed
parse-options: write blank line to correct output stream
t0040,t1502: Demonstrate parse_options bugs
git-rebase: don't ignore unexpected command line arguments
rev-parse parseopt: interpret any whitespace as start of help text
rev-parse parseopt: do not search help text for flag chars
t1502: demonstrate rev-parse --parseopt option mis-parsing
"git rev-parse" learned "--is-shallow-repository", that is to be
used in a way similar to existing "--is-bare-repository" and
friends.
* ow/rev-parse-is-shallow-repo:
rev-parse: rev-parse: add --is-shallow-repository
Running `git fetch --unshallow` on a repo that is not in fact shallow
produces a fatal error message. Add a helper to rev-parse that scripters
can use to determine whether a repo is shallow or not.
Signed-off-by: Øystein Walle <oystwa@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, rev-parse only interprets a space ' ' character as the
delimiter between the option spec and the help text. So if a tab
character is placed between the option spec and the help text, it will
be interpreted as part of the long option name or as part of the arg
hint. If it is interpreted as part of the long option name, then
rev-parse will produce what will be interpreted as multiple arguments
on the command line.
For example, the following option spec (note: there is a <tab> between
"frotz" and "enable"):
frotz enable frotzing
will produce the following set expression when --frotz is used:
set -- --frotz --
instead of this:
set -- --frotz enable --
Mark t1502.2 as fixed.
Signed-off-by: Brandon Casey <drafnel@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When searching for flag characters in the option spec, we should ensure
the search stays within the bounds of the option spec and does not enter
the help text portion of the spec. So when we find the boundary white
space marking the start of the help text, let's mark it with a nul
character. Then when we search for flag characters starting from the
beginning of the string we'll stop at the nul and won't enter the help
text.
Now, the following option spec:
exclame this does something!
will produce this 'set' expression when --exclame is specified:
set -- --exclame --
instead of this one:
set -- --exclame this does something --
Mark t1502.4 and t1502.5 as fixed.
Signed-off-by: Brandon Casey <drafnel@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Using for_each_ref_in() with a full refname has always been
a questionable practice, but it became an error with
b9c8e7f2fb (prefix_ref_iterator: don't trim too much,
2017-05-22), making "git rev-parse --bisect" pretty reliably
show a BUG.
Commit 03df567fbf (for_each_bisect_ref(): don't trim
refnames, 2017-06-18) fixed this case for revision.c, but
rev-parse handles this option on its own. We can use the
same solution here (and piggy-back on its test).
Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the flags for get_oid_with_context and friends to use "OID"
instead of "SHA1" in their names.
This transform was made by running the following one-liner on the
affected files:
perl -pi -e 's/GET_SHA1/GET_OID/g'
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix configuration codepath to pay proper attention to commondir
that is used in multi-worktree situation, and isolate config API
into its own header file.
* bw/config-h:
config: don't implicitly use gitdir or commondir
config: respect commondir
setup: teach discover_git_directory to respect the commondir
config: don't include config.h by default
config: remove git_config_iter
config: create config.h
Stop including config.h by default in cache.h. Instead only include
config.h in those files which require use of the config system.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Conversion from uchar[20] to struct object_id continues.
* bc/object-id: (53 commits)
object: convert parse_object* to take struct object_id
tree: convert parse_tree_indirect to struct object_id
sequencer: convert do_recursive_merge to struct object_id
diff-lib: convert do_diff_cache to struct object_id
builtin/ls-tree: convert to struct object_id
merge: convert checkout_fast_forward to struct object_id
sequencer: convert fast_forward_to to struct object_id
builtin/ls-files: convert overlay_tree_on_cache to object_id
builtin/read-tree: convert to struct object_id
sha1_name: convert internals of peel_onion to object_id
upload-pack: convert remaining parse_object callers to object_id
revision: convert remaining parse_object callers to object_id
revision: rename add_pending_sha1 to add_pending_oid
http-push: convert process_ls_object and descendants to object_id
refs/files-backend: convert many internals to struct object_id
refs: convert struct ref_update to use struct object_id
ref-filter: convert some static functions to struct object_id
Convert struct ref_array_item to struct object_id
Convert the verify_pack callback to struct object_id
Convert lookup_tag to struct object_id
...
* bc/object-id: (53 commits)
object: convert parse_object* to take struct object_id
tree: convert parse_tree_indirect to struct object_id
sequencer: convert do_recursive_merge to struct object_id
diff-lib: convert do_diff_cache to struct object_id
builtin/ls-tree: convert to struct object_id
merge: convert checkout_fast_forward to struct object_id
sequencer: convert fast_forward_to to struct object_id
builtin/ls-files: convert overlay_tree_on_cache to object_id
builtin/read-tree: convert to struct object_id
sha1_name: convert internals of peel_onion to object_id
upload-pack: convert remaining parse_object callers to object_id
revision: convert remaining parse_object callers to object_id
revision: rename add_pending_sha1 to add_pending_oid
http-push: convert process_ls_object and descendants to object_id
refs/files-backend: convert many internals to struct object_id
refs: convert struct ref_update to use struct object_id
ref-filter: convert some static functions to struct object_id
Convert struct ref_array_item to struct object_id
Convert the verify_pack callback to struct object_id
Convert lookup_tag to struct object_id
...
Convert lookup_commit, lookup_commit_or_die,
lookup_commit_reference, and lookup_commit_reference_gently to take
struct object_id arguments.
Introduce a temporary in parse_object buffer in order to convert this
function. This is required since in order to convert parse_object and
parse_object_buffer, lookup_commit_reference_gently and
lookup_commit_or_die would need to be converted. Not introducing a
temporary would therefore require that lookup_commit_or_die take a
struct object_id *, but lookup_commit would take unsigned char *,
leaving a confusing and hard-to-use interface.
parse_object_buffer will lose this temporary in a later patch.
This commit was created with manual changes to commit.c, commit.h, and
object.c, plus the following semantic patch:
@@
expression E1, E2;
@@
- lookup_commit_reference_gently(E1.hash, E2)
+ lookup_commit_reference_gently(&E1, E2)
@@
expression E1, E2;
@@
- lookup_commit_reference_gently(E1->hash, E2)
+ lookup_commit_reference_gently(E1, E2)
@@
expression E1;
@@
- lookup_commit_reference(E1.hash)
+ lookup_commit_reference(&E1)
@@
expression E1;
@@
- lookup_commit_reference(E1->hash)
+ lookup_commit_reference(E1)
@@
expression E1;
@@
- lookup_commit(E1.hash)
+ lookup_commit(&E1)
@@
expression E1;
@@
- lookup_commit(E1->hash)
+ lookup_commit(E1)
@@
expression E1, E2;
@@
- lookup_commit_or_die(E1.hash, E2)
+ lookup_commit_or_die(&E1, E2)
@@
expression E1, E2;
@@
- lookup_commit_or_die(E1->hash, E2)
+ lookup_commit_or_die(E1, E2)
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some of the functions converted are callers of lookup_commit_reference.
However, the changes involved in converting the entire thing are not too
large, so we might as well convert it all.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, Git's source code treats all timestamps as if they were
unsigned longs. Therefore, it is okay to write "%lu" when printing them.
There is a substantial problem with that, though: at least on Windows,
time_t is *larger* than unsigned long, and hence we will want to switch
away from the ill-specified `unsigned long` data type.
So let's introduce the pseudo format "PRItime" (currently simply being
defined to "lu") to make it easier to change the data type used for
timestamps.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Conversion from unsigned char [40] to struct object_id continues.
* bc/object-id:
Documentation: update and rename api-sha1-array.txt
Rename sha1_array to oid_array
Convert sha1_array_for_each_unique and for_each_abbrev to object_id
Convert sha1_array_lookup to take struct object_id
Convert remaining callers of sha1_array_lookup to object_id
Make sha1_array_append take a struct object_id *
sha1-array: convert internal storage for struct sha1_array to object_id
builtin/pull: convert to struct object_id
submodule: convert check_for_new_submodule_commits to object_id
sha1_name: convert disambiguate_hint_fn to take object_id
sha1_name: convert struct disambiguate_state to object_id
test-sha1-array: convert most code to struct object_id
parse-options-cb: convert sha1_array_append caller to struct object_id
fsck: convert init_skiplist to struct object_id
builtin/receive-pack: convert portions to struct object_id
builtin/pull: convert portions to struct object_id
builtin/diff: convert to struct object_id
Convert GIT_SHA1_RAWSZ used for allocation to GIT_MAX_RAWSZ
Convert GIT_SHA1_HEXSZ used for allocation to GIT_MAX_HEXSZ
Define new hash-size constants for allocating memory
Make sha1_array_for_each_unique take a callback using struct object_id.
Since one of these callbacks is an argument to for_each_abbrev, convert
those as well. Rename various functions, replacing "sha1" with "oid".
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We'd prefer to avoid unchecked snprintf calls because
truncation can lead to unexpected results.
These are all cases where truncation shouldn't ever happen,
because the input to snprintf is fixed in size. That makes
them candidates for xsnprintf(), but it's simpler still to
just use the heap, and then nobody has to wonder if "100" is
big enough.
We'll use xstrfmt() where possible, and a strbuf when we need
the resulting size or to reuse the same buffer in a loop.
Signed-off-by: Jeff King <peff@peff.net>
Code clean-up with minor bugfixes.
* jk/prefix-filename:
bundle: use prefix_filename with bundle path
prefix_filename: simplify windows #ifdef
prefix_filename: return newly allocated string
prefix_filename: drop length parameter
prefix_filename: move docstring to header file
hash-object: fix buffer reuse with --path in a subdirectory
