Refactoring the internal global data structure to make it possible
to open multiple repositories, work with and then close them.
Rerolled by Duy on top of a separate preliminary clean-up topic.
The resulting structure of the topics looked very sensible.
* sb/object-store: (27 commits)
sha1_file: allow sha1_loose_object_info to handle arbitrary repositories
sha1_file: allow map_sha1_file to handle arbitrary repositories
sha1_file: allow map_sha1_file_1 to handle arbitrary repositories
sha1_file: allow open_sha1_file to handle arbitrary repositories
sha1_file: allow stat_sha1_file to handle arbitrary repositories
sha1_file: allow sha1_file_name to handle arbitrary repositories
sha1_file: add repository argument to sha1_loose_object_info
sha1_file: add repository argument to map_sha1_file
sha1_file: add repository argument to map_sha1_file_1
sha1_file: add repository argument to open_sha1_file
sha1_file: add repository argument to stat_sha1_file
sha1_file: add repository argument to sha1_file_name
sha1_file: allow prepare_alt_odb to handle arbitrary repositories
sha1_file: allow link_alt_odb_entries to handle arbitrary repositories
sha1_file: add repository argument to prepare_alt_odb
sha1_file: add repository argument to link_alt_odb_entries
sha1_file: add repository argument to read_info_alternates
sha1_file: add repository argument to link_alt_odb_entry
sha1_file: add raw_object_store argument to alt_odb_usable
pack: move approximate object count to object store
...
The reason callers have to call this is to make sure either packed_git
or packed_git_mru pointers are initialized since we don't do that by
default. Sometimes it's hard to see this connection between where the
function is called and where packed_git pointer is used (sometimes in
separate functions).
Keep this dependency internal because now all access to packed_git and
packed_git_mru must go through get_xxx() wrappers.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a repository argument to allow prepare_packed_git callers to be
more specific about which repository to handle. See commit "sha1_file:
add repository argument to link_alt_odb_entry" for an explanation of
the #define trick.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
See previous patch for explanation.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a process with multiple repositories open, packfile accessors
should be associated to a single repository and not shared globally.
Move packed_git and packed_git_mru into the_repository and adjust
callers to reflect this.
[nd: while at there, wrap access to these two fields in get_packed_git()
and get_packed_git_mru(). This allows us to lazily initialize these
fields without caller doing that explicitly]
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>
Replace the custom binary search in unique_in_pack() with a call to
bsearch_pack(). This reduces code duplication and makes use of the
fan-out table of packs.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a process with multiple repositories open, alternates should be
associated to a single repository and not shared globally. Move
alt_odb_list and alt_odb_tail into the_repository and adjust callers
to reflect this.
Now that the alternative object data base is per repository, we're
leaking its memory upon freeing a repository. The next patch plugs
this hole.
No functional change intended.
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>
Migrate the struct alternate_object_database and all its related
functions to the object store as these functions are easier found in
that header. The migration is just a verbatim copy, no need to
include the object store header at any C file, because cache.h includes
repository.h which in turn includes the object-store.h
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When computing abbreviation lengths for an object ID against a single
packfile, the method find_abbrev_len_for_pack() currently implements
binary search. This is one of several implementations. One issue with
this implementation is that it ignores the fanout table in the pack-
index.
Translate this binary search to use the existing bsearch_pack() method
that correctly uses a fanout table.
Due to the use of the fanout table, the abbreviation computation is
slightly faster than before. For a fully-repacked copy of the Linux
repo, the following 'git log' commands improved:
* git log --oneline --parents --raw
Before: 59.2s
After: 56.9s
Rel %: -3.8%
* git log --oneline --parents
Before: 6.48s
After: 5.91s
Rel %: -8.9%
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This structure is only written to in one place, where we already have a
struct object_id. Convert the struct to use a struct object_id instead.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert get_tree_entry and find_tree_entry to take pointers to struct
object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert sha1_object_info and sha1_object_info_extended to take pointers
to struct object_id and rename them to use "oid" instead of "sha1" in
their names. Update the declaration and definition and apply the
following semantic patch, plus the standard object_id transforms:
@@
expression E1, E2;
@@
- sha1_object_info(E1.hash, E2)
+ oid_object_info(&E1, E2)
@@
expression E1, E2;
@@
- sha1_object_info(E1->hash, E2)
+ oid_object_info(E1, E2)
@@
expression E1, E2, E3;
@@
- sha1_object_info_extended(E1.hash, E2, E3)
+ oid_object_info_extended(&E1, E2, E3)
@@
expression E1, E2, E3;
@@
- sha1_object_info_extended(E1->hash, E2, E3)
+ oid_object_info_extended(E1, E2, E3)
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>
While finding unique object name abbreviation, the code may
accidentally have read beyond the end of the array of object names
in a pack.
* ds/find-unique-abbrev-optim:
sha1_name: fix uninitialized memory errors
During abbreviation checks, we navigate to the position within a
pack-index that an OID would be inserted and check surrounding OIDs
for the maximum matching prefix. This position may be beyond the
last position, because the given OID is lexicographically larger
than every OID in the pack. Then nth_packed_object_oid() does not
initialize "oid".
Use the return value of nth_packed_object_oid() to prevent these
errors.
Also the comment about checking near-by objects miscounts the
neighbours. If we have a hit at "first", we check "first-1" and
"first+1" to make sure we have sufficiently long abbreviation not to
match either. If we do not have a hit, "first" is the smallest
among the objects that are larger than what we want to name, so we
check that and "first-1" to make sure we have sufficiently long
abbreviation not to match either. In either case, we only check up
to two near-by objects.
Reported-by: Christian Couder <christian.couder@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
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>
"git branch" and "git checkout -b" are now forbidden from creating
a branch whose name is "HEAD".
* jc/branch-name-sanity:
builtin/branch: remove redundant check for HEAD
branch: correctly reject refs/heads/{-dash,HEAD}
branch: split validate_new_branchname() into two
branch: streamline "attr_only" handling in validate_new_branchname()
strbuf_check_branch_ref() is the central place where many codepaths
see if a proposed name is suitable for the name of a branch. It was
designed to allow us to get stricter than the check_refname_format()
check used for refnames in general, and we already use it to reject
a branch whose name begins with a '-'. The function gets a strbuf
and a string "name", and returns non-zero if the name is not
appropriate as the name for a branch. When the name is good, it
places the full refname for the branch with the proposed name in the
strbuf before it returns.
However, it turns out that one caller looks at what is in the strbuf
even when the function returns an error. Make the function populate
the strbuf even when it returns an error. That way, when "-dash" is
given as name, "refs/heads/-dash" is placed in the strbuf when
returning an error to copy_or_rename_branch(), which notices that
the user is trying to recover with "git branch -m -- -dash dash" to
rename "-dash" to "dash".
While at it, use the same mechanism to also reject "HEAD" as a
branch name.
Helped-by: Jeff King <peff@peff.net>
Helped-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git check-ref-format --branch @{-1}" bit a "BUG()" when run
outside a repository for obvious reasons; clarify the documentation
and make sure we do not even try to expand the at-mark magic in
such a case, but still call the validation logic for branch names.
* jc/check-ref-format-oor:
check-ref-format doc: --branch validates and expands <branch>
check-ref-format --branch: strip refs/heads/ using skip_prefix
check-ref-format --branch: do not expand @{...} outside repository
Conversion from uchar[20] to struct object_id continues.
* bc/object-id: (25 commits)
refs/files-backend: convert static functions to object_id
refs: convert read_raw_ref backends to struct object_id
refs: convert peel_object to struct object_id
refs: convert resolve_ref_unsafe to struct object_id
worktree: convert struct worktree to object_id
refs: convert resolve_gitlink_ref to struct object_id
Convert remaining callers of resolve_gitlink_ref to object_id
sha1_file: convert index_path and index_fd to struct object_id
refs: convert reflog_expire parameter to struct object_id
refs: convert read_ref_at to struct object_id
refs: convert peel_ref to struct object_id
builtin/pack-objects: convert to struct object_id
pack-bitmap: convert traverse_bitmap_commit_list to object_id
refs: convert dwim_log to struct object_id
builtin/reflog: convert remaining unsigned char uses to object_id
refs: convert dwim_ref and expand_ref to struct object_id
refs: convert read_ref and read_ref_full to object_id
refs: convert resolve_refdup and refs_resolve_refdup to struct object_id
Convert check_connected to use struct object_id
refs: update ref transactions to use struct object_id
...
Optimize the code to find shortest unique prefix of object names.
* ds/find-unique-abbrev-optim:
sha1_name: minimize OID comparisons during disambiguation
sha1_name: parse less while finding common prefix
sha1_name: unroll len loop in find_unique_abbrev_r()
p4211-line-log.sh: add log --online --raw --parents perf test
Running "git check-ref-format --branch @{-1}" from outside any
repository produces
$ git check-ref-format --branch @{-1}
BUG: environment.c:182: git environment hasn't been setup
This is because the expansion of @{-1} must come from the HEAD reflog,
which involves opening the repository. @{u} and @{push} (which are
more unusual because they typically would not expand to a local
branch) trigger the same assertion.
This has been broken since day one. Before v2.13.0-rc0~48^2
(setup_git_env: avoid blind fall-back to ".git", 2016-10-02), the
breakage was more subtle: Git would read reflogs from ".git" within
the current directory even if it was not a valid repository. Usually
that is harmless because Git is not being run from the root directory
of an invalid repository, but in edge cases such accesses can be
confusing or harmful. Since v2.13.0, the problem is easier to
diagnose because Git aborts with a BUG message.
Erroring out is the right behavior: when asked to interpret a branch
name like "@{-1}", there is no reasonable answer in this context.
But we should print a message saying so instead of an assertion failure.
We do not forbid "check-ref-format --branch" from outside a repository
altogether because it is ok for a script to pre-process branch
arguments without @{...} in such a context. For example, with
pre-2.13 Git, a script that does
branch='master'; # default value
parse_options
branch=$(git check-ref-format --branch "$branch")
to normalize an optional branch name provided by the user would work
both inside a repository (where the user could provide '@{-1}') and
outside (where '@{-1}' should not be accepted).
So disable the "expand @{...}" half of the feature when run outside a
repository, but keep the check of the syntax of a proposed branch
name. This way, when run from outside a repository, "git
check-ref-format --branch @{-1}" will gracefully fail:
$ git check-ref-format --branch @{-1}
fatal: '@{-1}' is not a valid branch name
and "git check-ref-format --branch master" will succeed as before:
$ git check-ref-format --branch master
master
restoring the usual pre-2.13 behavior.
[jn: split out from a larger patch; moved conditional to
strbuf_check_branch_ref instead of its caller; fleshed out commit
message; some style tweaks in tests]
Reported-by: Marko Kungla <marko.kungla@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the callers and internals, including struct read_ref_at_cb, of
read_ref_at to use struct object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
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>
Minimize OID comparisons during disambiguation of packfile OIDs.
Teach git to use binary search with the full OID to find the object's
position (or insertion position, if not present) in the pack-index.
The object before and immediately after (or the one at the insertion
position) give the maximum common prefix. No subsequent linear search
is required.
Take care of which two to inspect, in case the object id exists in the
packfile.
If the input to find_unique_abbrev_r() is a partial prefix, then the
OID used for the binary search is padded with zeroes so the object will
not exist in the repo (with high probability) and the same logic
applies.
This commit completes a series of three changes to OID abbreviation
code, and the overall change can be seen using standard commands for
large repos. Below we report performance statistics for perf test 4211.6
from p4211-line-log.sh using three copies of the Linux repo:
| Packs | Loose | HEAD~3 | HEAD | Rel% |
|-------|--------|----------|----------|-------|
| 1 | 0 | 41.27 s | 38.93 s | -4.8% |
| 24 | 0 | 98.04 s | 91.35 s | -5.7% |
| 23 | 323952 | 117.78 s | 112.18 s | -4.8% |
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Create get_hex_char_from_oid() to parse oids one hex character at a
time. This prevents unnecessary copying of hex characters in
extend_abbrev_len() when finding the length of a common prefix.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Unroll the while loop inside find_unique_abbrev_r to avoid iterating
through all loose objects and packfiles multiple times when the short
name is longer than the predicted length.
Instead, inspect each object that collides with the estimated
abbreviation to find the longest common prefix.
The focus of this change is to refactor the existing method in a way
that clearly does not change the current behavior. In some cases, the
new method is slower than the previous method. Later changes will
correct all performance loss.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A common mistake when writing binary search is to allow possible
integer overflow by using the simple average:
mid = (min + max) / 2;
Instead, use the overflow-safe version:
mid = min + (max - min) / 2;
This translation is safe since the operation occurs inside a loop
conditioned on "min < max". The included changes were found using
the following git grep:
git grep '/ *2;' '*.c'
Making this cleanup will prevent future review friction when a new
binary search is contructed based on existing code.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
alloc_packed_git() in packfile.c is duplicated from sha1_file.c. In a
subsequent commit, alloc_packed_git() will be removed from sha1_file.c.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are several uses of the constant 40 in find_unique_abbrev_r.
Convert them to GIT_SHA1_HEXSZ.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
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>
Convert code that divides and rounds up to use DIV_ROUND_UP to make the
intent clearer and reduce the number of magic constants.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Optimize "what are the object names already taken in an alternate
object database?" query that is used to derive the length of prefix
an object name is uniquely abbreviated to.
* rs/sha1-name-readdir-optim:
sha1_file: guard against invalid loose subdirectory numbers
sha1_file: let for_each_file_in_obj_subdir() handle subdir names
p4205: add perf test script for pretty log formats
sha1_name: cache readdir(3) results in find_short_object_filename()
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
The function for_each_file_in_obj_subdir() takes a object subdirectory
number and expects the name of the same subdirectory to be included in
the path strbuf. Avoid this redundancy by letting the function append
the hexadecimal subdirectory name itself. This makes it a bit easier
and safer to use the function -- it becomes impossible to specify
different subdirectories in subdir_nr and path.
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Read each loose object subdirectory at most once when looking for unique
abbreviated hashes. This speeds up commands like "git log --pretty=%h"
considerably, which previously caused one readdir(3) call for each
candidate, even for subdirectories that were visited before.
The new cache is kept until the program ends and never invalidated. The
same is already true for pack indexes. The inherent racy nature of
finding unique short hashes makes it still fit for this purpose -- a
conflicting new object may be added at any time. Tasks with higher
consistency requirements should not use it, though.
The cached object names are stored in an oid_array, which is quite
compact. The bitmap for remembering which subdir was already read is
stored as a char array, with one char per directory -- that's not quite
as compact, but really simple and incurs only an overhead equivalent to
11 hashes after all.
Suggested-by: Jeff King <peff@peff.net>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
Our code often opens a path to an optional file, to work on its
contents when we can successfully open it. We can ignore a failure
to open if such an optional file does not exist, but we do want to
report a failure in opening for other reasons (e.g. we got an I/O
error, or the file is there, but we lack the permission to open).
The exact errors we need to ignore are ENOENT (obviously) and
ENOTDIR (less obvious). Instead of repeating comparison of errno
with these two constants, introduce a helper function to do so.
* jc/noent-notdir:
treewide: use is_missing_file_error() where ENOENT and ENOTDIR are checked
compat-util: is_missing_file_error()
The result from "git diff" that compares two blobs, e.g. "git diff
$commit1:$path $commit2:$path", used to be shown with the full
object name as given on the command line, but it is more natural to
use the $path in the output and use it to look up .gitattributes.
* jk/diff-blob:
diff: use blob path for blob/file diffs
diff: use pending "path" if it is available
diff: use the word "path" instead of "name" for blobs
diff: pass whole pending entry in blobinfo
handle_revision_arg: record paths for pending objects
handle_revision_arg: record modes for "a..b" endpoints
t4063: add tests of direct blob diffs
get_sha1_with_context: dynamically allocate oc->path
get_sha1_with_context: always initialize oc->symlink_path
sha1_name: consistently refer to object_context as "oc"
handle_revision_arg: add handle_dotdot() helper
handle_revision_arg: hoist ".." check out of range parsing
handle_revision_arg: stop using "dotdot" as a generic pointer
handle_revision_arg: simplify commit reference lookups
handle_revision_arg: reset "dotdot" consistently
Using the is_missing_file_error() helper introduced in the previous
step, update all hits from
$ git grep -e ENOENT --and -e ENOTDIR
There are codepaths that only check ENOENT, and it is possible that
some of them should be checking both. Updating them is kept out of
this step deliberately, as we do not want to change behaviour in this
step.
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
...
When a sha1 lookup returns the tree path via "struct
object_context", it just copies it into a fixed-size buffer.
This means the result can be truncated, and it means our
"struct object_context" consumes a lot of stack space.
Instead, let's allocate a string on the heap. Because most
callers don't care about this information, we'll avoid doing
it by default (so they don't all have to start calling
free() on the result). There are basically two options for
the caller to signal to us that it's interested:
1. By setting a pointer to storage in the object_context.
2. By passing a flag in another parameter.
Doing (1) would match the way that sha1_object_info_extended()
works. But it would mean that every caller would have to
initialize the object_context, which they don't currently
have to do.
This patch does (2), and adds a new bit to the function's
flags field. All of the callers that look at the "path"
field are updated to pass the new flag.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The get_sha1_with_context() function zeroes out the
oc->symlink_path strbuf, but doesn't use strbuf_init() to
set up the usual invariants (like pointing to the slopbuf).
We don't actually write to the oc->symlink_path strbuf
unless we call get_tree_entry_follow_symlinks(), and that
function does initialize it. However, readers may still look
at the zero'd strbuf.
In practice this isn't a triggerable bug. The only caller
that looks at it only does so when the mode we found is 0.
This doesn't happen for non-tree-entries (where we return
S_IFINVALID). A broken tree entry could have a mode of 0,
but canon_mode() quietly rewrites that into S_IFGITLINK.
So the "0" mode should only come up when we did indeed find
a symlink.
This is mostly just an accident of how the code happens to
work, though. Let's future-proof ourselves to make sure the
strbuf is properly initialized for all calls (it's only a
few struct member assignments, not a heap allocation).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
An early version of the patch to add object_context used the
name object_resolve_context. This was later shortened to
just object_context, but the "orc" variable name stuck in a
few places. Let's use "oc", which is used elsewhere in the
code.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
