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>
Convert lookup_tag to 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>
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>
There are a small number of remaining callers of lookup_commit_reference
and lookup_commit_reference_gently that still need to be converted to
struct object_id. Convert these.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git's source code assumes that unsigned long is at least as precise as
time_t. Which is incorrect, and causes a lot of problems, in particular
where unsigned long is only 32-bit (notably on Windows, even in 64-bit
versions).
So let's just use a more appropriate data type instead. In preparation
for this, we introduce the new `timestamp_t` data type.
By necessity, this is a very, very large patch, as it has to replace all
timestamps' data type in one go.
As we will use a data type that is not necessarily identical to `time_t`,
we need to be very careful to use `time_t` whenever we interact with the
system functions, and `timestamp_t` everywhere else.
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
Since this structure handles an array of object IDs, rename it to struct
oid_array. Also rename the accessor functions and the initialization
constant.
This commit was produced mechanically by providing non-Documentation
files to the following Perl one-liners:
perl -pi -E 's/struct sha1_array/struct oid_array/g'
perl -pi -E 's/\bsha1_array_/oid_array_/g'
perl -pi -E 's/SHA1_ARRAY_INIT/OID_ARRAY_INIT/g'
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
Convert the callers to pass struct object_id by changing the function
declaration and definition and applying the following semantic patch:
@@
expression E1, E2;
@@
- sha1_array_append(E1, E2.hash)
+ sha1_array_append(E1, &E2)
@@
expression E1, E2;
@@
- sha1_array_append(E1, E2->hash)
+ sha1_array_append(E1, E2)
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert this function pointer type and the functions that implement it
to take a struct object_id. Introduce a temporary in
show_ambiguous_object to avoid having to convert for_each_abbrev at this
point.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert struct disambiguate_state to use struct object_id by changing
the structure definition and applying the following semantic patch:
@@
struct disambiguate_state E1;
@@
- E1.bin_pfx
+ E1.bin_pfx.hash
@@
struct disambiguate_state *E1;
@@
- E1->bin_pfx
+ E1->bin_pfx.hash
@@
struct disambiguate_state E1;
@@
- E1.candidate
+ E1.candidate.hash
@@
struct disambiguate_state *E1;
@@
- E1->candidate
+ E1->candidate.hash
This conversion is needed so we can convert disambiguate_hint_fn later.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the revision parsing logic to match @{upstream}, @{u} & @{push}
case-insensitively.
Before this change supplying anything except the lower-case forms
emits an "unknown revision or path not in the working tree"
error. This change makes upper-case & mixed-case versions equivalent
to the lower-case versions.
The use-case for this is being able to hold the shift key down while
typing @{u} on certain keyboard layouts, which makes the sequence
easier to type, and reduces cases where git throws an error at the
user where it could do what he means instead.
These suffixes now join various other suffixes & special syntax
documented in gitrevisions(7) that matches case-insensitively. A table
showing the status of the various forms documented there before &
after this patch is shown below. The key for the table is:
- CI = Case Insensitive
- CIP = Case Insensitive Possible (without ambiguities)
- AG = Accepts Garbage (.e.g. @{./.4.minutes./.})
Before this change:
|----------------+-----+------+-----|
| What? | CI? | CIP? | AG? |
|----------------+-----+------+-----|
| @{<date>} | Y | Y | Y |
| @{upstream} | N | Y | N |
| @{push} | N | Y | N |
|----------------+-----+------+-----|
After it:
|----------------+-----+------+-----|
| What? | CI? | CIP? | AG? |
|----------------+-----+------+-----|
| @{<date>} | Y | Y | Y |
| @{upstream} | Y | Y | N |
| @{push} | Y | Y | N |
|----------------+-----+------+-----|
The ^{<type>} suffix is not made case-insensitive, because other
places that take <type> like "cat-file -t <type>" do want them case
sensitively (after all we never declared that type names are case
insensitive). Allowing case-insensitive typename only with this syntax
will make the resulting Git as a whole inconsistent.
This change was independently authored to scratch a longtime itch, but
when I was about to submit it I discovered that a similar patch had
been submitted unsuccessfully before by Conrad Irwin in August 2011 as
"rev-parse: Allow @{U} as a synonym for
@{u}" (<1313287071-7851-1-git-send-email-conrad.irwin@gmail.com>).
The tests for this patch are more exhaustive than in the 2011
submission. The starting point for them was to first change the code
to only support upper-case versions of the existing words, seeing what
broke, and amending the breaking tests to check upper case & mixed
case as appropriate, and where not redundant to other similar
tests. The implementation itself is equivalent.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since we will likely be introducing a new hash function at some point,
and that hash function might be longer than 20 bytes, use the constant
GIT_MAX_RAWSZ, which is designed to be suitable for allocations, instead
of GIT_SHA1_RAWSZ. This will ease the transition down the line by
distinguishing between places where we need to allocate memory suitable
for the largest hash from those where we need to handle the current
hash.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since we will likely be introducing a new hash function at some point,
and that hash function might be longer than 40 hex characters, use the
constant GIT_MAX_HEXSZ, which is designed to be suitable for
allocations, instead of GIT_SHA1_HEXSZ. This will ease the transition
down the line by distinguishing between places where we need to allocate
memory suitable for the largest hash from those where we need to handle
the current hash.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function asks strbuf_branchname() to expand any @-marks
in the branchname, and then we blindly stick refs/heads/ in
front of the result. This is obviously nonsense if the
expansion is "HEAD" or a ref in refs/remotes/.
The most obvious end-user effect is that creating or
renaming a branch with an expansion may have confusing
results (e.g., creating refs/heads/origin/master from
"@{upstream}" when the operation should be disallowed).
We can fix this by telling strbuf_branchname() that we are
only interested in local expansions. Any unexpanded bits are
then fed to check_ref_format(), which either disallows them
(in the case of "@{upstream}") or lets them through
("refs/heads/@" is technically valid, if a bit silly).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The interpret_branch_name() function converts names like
@{-1} and @{upstream} into branch names. The expanded ref
names are not fully qualified, and may be outside of the
refs/heads/ namespace (e.g., "@" expands to "HEAD", and
"@{upstream}" is likely to be in "refs/remotes/").
This is OK for callers like dwim_ref() which are primarily
interested in resolving the resulting name, no matter where
it is. But callers like "git branch" treat the result as a
branch name in refs/heads/. When we expand to a ref outside
that namespace, the results are very confusing (e.g., "git
branch @" tries to create refs/heads/HEAD, which is
nonsense).
Callers can't know from the returned string how the
expansion happened (e.g., did the user really ask for a
branch named "HEAD", or did we do a bogus expansion?). One
fix would be to return some out-parameters describing the
types of expansion that occurred. This has the benefit that
the caller can generate precise error messages ("I
understood @{upstream} to mean origin/master, but that is a
remote tracking branch, so you cannot create it as a local
name").
However, out-parameters make the function interface somewhat
cumbersome. Instead, let's do the opposite: let the caller
tell us which elements to expand. That's easier to pass in,
and none of the callers give more precise error messages
than "@{upstream} isn't a valid branch name" anyway (which
should be sufficient).
The strbuf_branchname() function needs a similar parameter,
as most of the callers access interpret_branch_name()
through it.
We can break the callers down into two groups:
1. Callers that are happy with any kind of ref in the
result. We pass "0" here, so they continue to work
without restrictions. This includes merge_name(),
the reflog handling in add_pending_object_with_path(),
and substitute_branch_name(). This last is what powers
dwim_ref().
2. Callers that have funny corner cases (mostly in
git-branch and git-checkout). These need to make use of
the new parameter, but I've left them as "0" in this
patch, and will address them individually in follow-on
patches.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The return value from strbuf_branchname() is confusing and
useless: it's 0 if the whole name was consumed by an @-mark,
but otherwise is the length of the original name we fed.
No callers actually look at the return value, so let's just
get rid of it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We generally put docstrings with function declarations,
because it's the callers who need to know how the function
works. Let's do so for interpret_branch_name().
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The interpret_branch_name() function takes a ptr/len pair
for the name, but you can pass "0" for "namelen", which will
cause it to check the length with strlen().
However, before we do that auto-namelen magic, we call
interpret_nth_prior_checkout(), which gets fed the bogus
"0". This was broken by 8cd4249c4 (interpret_branch_name:
always respect "namelen" parameter, 2014-01-15). Though to
be fair to that commit, it was broken in the _opposite_
direction before, where we would always treat "name" as a
string even if a length was passed.
You can see the bug with "git log -g @{-1}". That code path
always passes "0", and without this patch it cannot figure
out which branch's reflog to show.
We can fix it by a small reordering of the code.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make each_reflog_ent_fn take two struct object_id pointers instead of
two pointers to unsigned char. Convert the various callbacks to use
struct object_id as well. Also, rename fsck_handle_reflog_sha1 to
fsck_handle_reflog_oid.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Overflow is defined for unsigned integers, but not for signed ones.
Wrap around explicitly for the new ring-buffer in find_unique_abbrev()
as we did in bb84735c for the ones in sha1_to_hex() and get_pathname(),
thus avoiding signed overflows and getting rid of the magic number 3.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update "git diff --no-index" codepath not to try to peek into .git/
directory that happens to be under the current directory, when we
know we are operating outside any repository.
* jk/no-looking-at-dotgit-outside-repo:
diff: handle sha1 abbreviations outside of repository
diff_aligned_abbrev: use "struct oid"
diff_unique_abbrev: rename to diff_aligned_abbrev
find_unique_abbrev: use 4-buffer ring
test-*-cache-tree: setup git dir
read info/{attributes,exclude} only when in repository
Updates the way approximate count of total objects is computed
while attempting to come up with a unique abbreviated object name,
which in turn needs to estimate how many hexdigits are necessary to
ensure uniqueness.
* jk/abbrev-auto:
find_unique_abbrev: move logic out of get_short_sha1()
Allow the default abbreviation length, which has historically been
7, to scale as the repository grows. The logic suggests to use 12
hexdigits for the Linux kernel, and 9 to 10 for Git itself.
* lt/abbrev-auto:
abbrev: auto size the default abbreviation
abbrev: prepare for new world order
abbrev: add FALLBACK_DEFAULT_ABBREV to prepare for auto sizing
Some code paths want to format multiple abbreviated sha1s in
the same output line. Because we use a single static buffer
for our return value, they have to either break their output
into several calls or allocate their own arrays and use
find_unique_abbrev_r().
Intead, let's mimic sha1_to_hex() and use a ring of several
buffers, so that the return value stays valid through
multiple calls. This shortens some of the callers, and makes
it harder to for them to make a silly mistake.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Codepaths involved in interacting alternate object store have
been cleaned up.
* jk/alt-odb-cleanup:
alternates: use fspathcmp to detect duplicates
sha1_file: always allow relative paths to alternates
count-objects: report alternates via verbose mode
fill_sha1_file: write into a strbuf
alternates: store scratch buffer as strbuf
fill_sha1_file: write "boring" characters
alternates: use a separate scratch space
alternates: encapsulate alt->base munging
alternates: provide helper for allocating alternate
alternates: provide helper for adding to alternates list
link_alt_odb_entry: refactor string handling
link_alt_odb_entry: handle normalize_path errors
t5613: clarify "too deep" recursion tests
t5613: do not chdir in main process
t5613: whitespace/style cleanups
t5613: use test_must_fail
t5613: drop test_valid_repo function
t5613: drop reachable_via function
We pre-size the scratch buffer to hold a loose object
filename of the form "xx/yyyy...", which leads to allocation
code that is hard to verify. We have to use some magic
numbers during the initial allocation, and then writers must
blindly assume that the buffer is big enough. Using a strbuf
makes it more clear that we cannot overflow.
Unfortunately, we do still need some magic numbers to grow
our strbuf before calling fill_sha1_path(), but the strbuf
growth is much closer to the point of use. This makes it
easier to see that it's correct, and opens the possibility
of pushing it even further down if fill_sha1_path() learns
to work on strbufs.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The alternate_object_database struct uses a single buffer
both for storing the path to the alternate, and as a scratch
buffer for forming object names. This is efficient (since
otherwise we'd end up storing the path twice), but it makes
life hard for callers who just want to know the path to the
alternate. They have to remember to stop reading after
"alt->name - alt->base" bytes, and to subtract one for the
trailing '/'.
It would be much simpler if they could simply access a
NUL-terminated path string. We could encapsulate this in a
function which puts a NUL in the scratch buffer and returns
the string, but that opens up questions about the lifetime
of the result. The first time another caller uses the
alternate, the scratch buffer may get other data tacked onto
it.
Let's instead just store the root path separately from the
scratch buffer. There aren't enough alternates being stored
for the duplicated data to matter for performance, and this
keeps things simple and safe for the callers.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Allocating a struct alternate_object_database is tricky, as
we must over-allocate the buffer to provide scratch space,
and then put in particular '/' and NUL markers.
Let's encapsulate this in a function so that the complexity
doesn't leak into callers (and so that we can modify it
later).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The get_short_sha1() is only about reading short sha1s; we
do call it in a loop to check "is this long enough" for each
object, but otherwise it should not need to know about
things like our default_abbrev setting.
So instead of asking it to set default_automatic_abbrev as a
side-effect, let's just have find_unique_abbrev() pick the
right place to start its loop. This requires a separate
approximate_object_count() function, but that naturally
belongs with the rest of sha1_file.c.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In fairly early days we somehow decided to abbreviate object names
down to 7-hexdigits, but as projects grow, it is becoming more and
more likely to see such a short object names made in earlier days
and recorded in the log messages no longer unique.
Currently the Linux kernel project needs 11 to 12 hexdigits, while
Git itself needs 10 hexdigits to uniquely identify the objects they
have, while many smaller projects may still be fine with the
original 7-hexdigit default. One-size does not fit all projects.
Introduce a mechanism, where we estimate the number of objects in
the repository upon the first request to abbreviate an object name
with the default setting and come up with a sane default for the
repository. Based on the expectation that we would see collision in
a repository with 2^(2N) objects when using object names shortened
to first N bits, use sufficient number of hexdigits to cover the
number of objects in the repository. Each hexdigit (4-bits) we add
to the shortened name allows us to have four times (2-bits) as many
objects in the repository.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we find ambiguous short sha1s, we may get a
disambiguation rule from our caller's context. But if we
don't, we fall back to treating all sha1s the same, even
though most projects will tend to refer only to commits by
their short sha1s.
This patch introduces a configuration option that lets the
user pick a different fallback (e.g., only commits). It's
possible that we may want to make this the default, but it's
a good idea to start as a config option for two reasons:
1. It lets people experiment with this and see if it's a
good idea (i.e., the "tend to" above is an assumption;
we don't really know if this will break some obscure
cases).
2. Even if we do flip the default, it gives people an
escape hatch if it causes problems (you can sometimes
override it by asking for "1234^{tree}", but not all
combinations are possible).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the user gives us an ambiguous short sha1, we print an
error and refuse to resolve it. In some cases, the next step
is for them to feed us more characters (e.g., if they were
retyping or cut-and-pasting from a full sha1). But in other
cases, that might be all they have. For example, an old
commit message may have used a 7-character hex that was
unique at the time, but is now ambiguous. Git doesn't
provide any information about the ambiguous objects it
found, so it's hard for the user to find out which one they
probably meant.
This patch teaches get_short_sha1() to list the sha1s of the
objects it found, along with a few bits of information that
may help the user decide which one they meant. Here's what
it looks like on git.git:
$ git rev-parse b2e1
error: short SHA1 b2e1 is ambiguous
hint: The candidates are:
hint: b2e1196 tag v2.8.0-rc1
hint: b2e11d1 tree
hint: b2e1632 commit 2007-11-14 - Merge branch 'bs/maint-commit-options'
hint: b2e1759 blob
hint: b2e18954 blob
hint: b2e1895c blob
fatal: ambiguous argument 'b2e1': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'
We show the tagname for tags, and the date and subject for
commits. For trees and blobs, in theory we could dig in the
history to find the paths at which they were present. But
that's very expensive (on the order of 30s for the kernel),
and it's not likely to be all that helpful. Most short
references are to commits, so the useful information is
typically going to be that the object in question _isn't_ a
commit. So it's silly to spend a lot of CPU preemptively
digging up the path; the user can do it themselves if they
really need to.
And of course it's somewhat ironic that we abbreviate the
sha1s in the disambiguation hint. But full sha1s would cause
annoying line wrapping for the commit lines, and presumably
the user is going to just re-issue their command immediately
with the corrected sha1.
We also restrict the list to those that match any
disambiguation hint. E.g.:
$ git rev-parse b2e1:foo
error: short SHA1 b2e1 is ambiguous
hint: The candidates are:
hint: b2e1196 tag v2.8.0-rc1
hint: b2e11d1 tree
hint: b2e1632 commit 2007-11-14 - Merge branch 'bs/maint-commit-options'
fatal: Invalid object name 'b2e1'.
does not bother reporting the blobs, because they cannot
work as a treeish.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If an object appears multiple times in the object database
(e.g., in both loose and packed form, or in two separate
packs), the disambiguation machinery may see it more than
once. The get_short_sha1() function handles this already,
but for_each_abbrev() blindly fires the callback for each
instance it finds.
We can fix this by collecting the output in a sha1 array and
de-duplicating it. As a bonus, the sort done for the
de-duplication means that our output will be stable,
regardless of the order in which the objects are found.
Note that the old code normalized the callback's output to
0/1 to store in the 1-bit ds->ambiguous flag (which both
halted the iteration and was returned from the
for_each_abbrev function). Now that we are using sha1_array,
we can return the real value. In practice, it doesn't matter
as the sole caller only ever returns 0.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a human-readable message, and there's no reason it
should not be translated. While we're at it, let's drop the
period from the end, which is not our usual style.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We store the hex prefix in a 40-byte buffer with the prefix
itself followed by 40-minus-len "x" characters. These x's
serve no purpose, and the lack of NUL termination makes the
prefix string annoying to use. Let's just terminate it.
Note that this is in contrast to the binary prefix, which
_must_ be zero-padded, because we look at the whole thing
during a binary search to find the first potential match in
each pack index. The loose-object hex search cannot use the
same trick because it has to do a linear walk through the
unsorted results of readdir() (and even if it could, you'd
want zeroes instead of x's).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The disambiguation machinery has two callers: get_short_sha1
and for_each_abbrev. Both need to repeat much of the same
setup: declaring buffers, sanity-checking lengths, preparing
the prefixes, etc. Let's pull that into a single init
function so we can avoid repeating ourselves.
Pulling the buffers into the "struct disambiguate_state"
isn't strictly necessary, but it does make things simpler
for the callers, who no longer have to worry about sizing
them correctly (i.e., it's an implicit requirement that
the caller provide 20- and 40-byte buffers).
And while we're touching this code, we can convert any
magic-number sizes to the more modern GIT_SHA1_* constants.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The treeish disambiguation function tries to peel tags, but
it does so by calling:
deref_tag(lookup_object(sha1), ...);
This will only work if we have previously looked at the tag
and created a "struct tag" for it. Since parsing revision
arguments typically happens before anything else, this is
usually not the case, and we would fail to peel the tag (we
are lucky that deref_tag() gracefully handles the NULL and
does not segfault).
Instead, we can use parse_object(). Note that this is the
same fix done by 94d75d1 (get_short_sha1(): correctly
disambiguate type-limited abbreviation, 2013-07-01), but
that commit fixed only the committish disambiguator, and
left the bug in the treeish one.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The get_sha1() function is actually implementation by many
sub-functions, but we do not always pass our flags around to
all of those functions. As a result, we may forget that our
caller asked us to resolve with GET_SHA1_QUIETLY and output
messages. The two triggerable cases are:
1. Resolving treeish:path will resolve the "treeish"
portion using GET_SHA1_TREEISH, dropping all other
flags.
2. The peel_onion() function did not take flags at all
but recurses to get_sha1_1(), which does.
The solution for both is to bitwise-OR their new flags with
the existing ones (after dropping any mutually exclusive
disambiguation flags).
This bug can trigger with "git rev-parse --quiet", which
asks for quiet resolution. But it can also happen in a more
vanilla code path when we do a follow-up ONLY_TO_DIE
invocation of get_sha1(), and that's what the tests check.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the revision code cannot parse an argument like
"HEAD:foo", it will call maybe_die_on_misspelt_object_name(),
which re-runs get_sha1() with an extra ONLY_TO_DIE flag. We
then spend more effort to generate a better error message.
Unfortunately, a side effect is that our second call may
repeat the same error messages from the original get_sha1()
call. You can see this with:
$ git show 0017
error: short SHA1 0017 is ambiguous.
error: short SHA1 0017 is ambiguous.
fatal: ambiguous argument '0017': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'
where the second "error:" line comes from the ONLY_TO_DIE
call.
To fix this, we can make ONLY_TO_DIE imply QUIETLY. This is
a little odd, because the whole point of ONLY_TO_DIE is to
output error messages. But what we want to do is tell the
rest of the get_sha1() code (particularly get_sha1_1()) that
the _regular_ messages should be quiet, but the only-to-die
ones should not.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
