The variable tracking whether or not we want to honor includes is
tracked via a global variable. Move it into the location options
instead.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The default value is tracked via a global variable. Move it into the
display options instead.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The type options are tracked via a global variable. Move it into the
display options instead.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The display options are tracked via a set of global variables. Move
them into a self-contained structure so that we can easily parse all
relevant options and hand them over to the various functions that
require them.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The location options are tracked via a set of global variables. Move
them into a self-contained structure so that we can easily parse all
relevant options and hand them over to the various functions that
require them.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Refactor functions to have a single exit path. This will make it easier
in subsequent commits to add common cleanup code.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `check_write()` function verifies that we do not try to write to a
config source that cannot be written to, like for example stdin. But
while the new subcommands do call this function, they do so before
calling `handle_config_location()`. Consequently, we only end up
checking the default config location for writeability, not the location
that was actually specified by the caller of git-config(1).
Fix this by calling `check_write()` after `handle_config_location()`. We
will further clarify the relationship between those two functions in a
subsequent commit where we remove the global state that both implicitly
rely on.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We only use actions in the legacy mode. Convert them to an enum and move
them into `cmd_config_actions()` to clearly demonstrate that they are
not used anywhere else.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the legacy options as well some of the variables it references into
`cmd_config_action()`. This reduces our reliance on global state.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the subcommand options as well as the `subcommand` variable into
`cmd_config()`. This reduces our reliance on global state.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In `cmd_config()` we first try to parse the provided arguments as
subcommands and, if this is successful, call the respective functions
of that subcommand. Otherwise we continue with the "legacy" mode that
uses implicit actions and/or flags.
Disentangle this by moving the legacy mode into its own function. This
allows us to move the options into the respective functions and clearly
separates concerns.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When invoking git-config(1) with a wrong set of arguments we end up
calling `usage_builtin_config()` after printing an error message that
says what was wrong. As that function ends up printing the full list of
options, which is quite long, the actual error message will be buried by
a wall of text. This makes it really hard to figure out what exactly
caused the error.
Furthermore, now that we have recently introduced subcommands, the usage
information may actually be misleading as we unconditionally print
options of the subcommand-less mode.
Fix both of these issues by just not printing the options at all
anymore. Instead, we call `usage()` that makes us report in a single
line what has gone wrong. This should be way more discoverable for our
users and addresses the inconsistency.
Furthermore, this change allow us to inline the options into the
respective functions that use them to parse the command line.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that there is clearer memory ownership around the bitmap_writer
structure, introduce a bitmap_writer_free() function that callers may
use to free any memory associated with their instance of the
bitmap_writer structure.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `max_bitmaps` parameter in `bitmap_writer_select_commits()` was
introduced back in 7cc8f97108 (pack-objects: implement bitmap writing,
2013-12-21), making it original to the bitmap implementation in Git
itself.
When that patch was merged via 0f9e62e084 (Merge branch
'jk/pack-bitmap', 2014-02-27), its sole caller in builtin/pack-objects.c
passed a value of "-1" for `max_bitmaps`, indicating no limit.
Since then, the only other caller (in midx.c, added via c528e17966
(pack-bitmap: write multi-pack bitmaps, 2021-08-31)) also uses a value
of "-1" for `max_bitmaps`.
Since no callers have needed a finite limit for the `max_bitmaps`
parameter in the nearly decade that has passed since 0f9e62e084, let's
remove the parameter and any dead pieces of code connected to it.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The pack-bitmap machinery uses a structure called 'bitmap_writer' to
collect the data necessary to write out .bitmap files. Since its
introduction in 7cc8f97108 (pack-objects: implement bitmap writing,
2013-12-21), there has been a single static bitmap_writer structure,
which is responsible for all bitmap writing-related operations.
In practice, this is OK, since we are only ever writing a single .bitmap
file in a single process (e.g., `git multi-pack-index write --bitmap`,
`git pack-objects --write-bitmap-index`, `git repack -b`, etc.).
However, having a single static variable makes issues like data
ownership unclear, when to free variables, what has/hasn't been
initialized unclear.
Refactor this code to be written in terms of a given bitmap_writer
structure instead of relying on a static global.
Note that this exposes the structure definition of the bitmap_writer at
the pack-bitmap.h level. We could work around this by, e.g., forcing
callers to declare their writers as:
struct bitmap_writer *writer;
bitmap_writer_init(&bitmap_writer);
and then declaring `bitmap_writer_init()` as taking in a double-pointer
like so:
void bitmap_writer_init(struct bitmap_writer **writer);
which would avoid us having to expose the definition of the structure
itself. This patch takes a different approach, since future patches
(like for the ongoing pseudo-merge bitmaps work) will want to modify the
innards of this structure (in the previous example, via pseudo-merge.c).
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* tag 'v2.45.1': (42 commits)
Git 2.45.1
Git 2.44.1
Git 2.43.4
Git 2.42.2
Git 2.41.1
Git 2.40.2
Git 2.39.4
fsck: warn about symlink pointing inside a gitdir
core.hooksPath: add some protection while cloning
init.templateDir: consider this config setting protected
clone: prevent hooks from running during a clone
Add a helper function to compare file contents
init: refactor the template directory discovery into its own function
find_hook(): refactor the `STRIP_EXTENSION` logic
clone: when symbolic links collide with directories, keep the latter
entry: report more colliding paths
t5510: verify that D/F confusion cannot lead to an RCE
submodule: require the submodule path to contain directories only
clone_submodule: avoid using `access()` on directories
submodules: submodule paths must not contain symlinks
...
* ps/undecided-is-not-necessarily-sha1:
repository: stop setting SHA1 as the default object hash
oss-fuzz/commit-graph: set up hash algorithm
builtin/shortlog: don't set up revisions without repo
builtin/diff: explicitly set hash algo when there is no repo
builtin/bundle: abort "verify" early when there is no repository
builtin/blame: don't access potentially unitialized `the_hash_algo`
builtin/rev-parse: allow shortening to more than 40 hex characters
remote-curl: fix parsing of detached SHA256 heads
attr: fix BUG() when parsing attrs outside of repo
attr: don't recompute default attribute source
parse-options-cb: only abbreviate hashes when hash algo is known
path: move `validate_headref()` to its only user
path: harden validation of HEAD with non-standard hashes
The singleton index_state instance "the_index" has been eliminated
by always instantiating "the_repository" and replacing references
to "the_index" with references to its .index member.
* ps/the-index-is-no-more:
repository: drop `initialize_the_repository()`
repository: drop `the_index` variable
builtin/clone: stop using `the_index`
repository: initialize index in `repo_init()`
builtin: stop using `the_index`
t/helper: stop using `the_index`
The credential helper protocol, together with the HTTP layer, have
been enhanced to support authentication schemes different from
username & password pair, like Bearer and NTLM.
* bc/credential-scheme-enhancement:
credential: add method for querying capabilities
credential-cache: implement authtype capability
t: add credential tests for authtype
credential: add support for multistage credential rounds
t5563: refactor for multi-stage authentication
docs: set a limit on credential line length
credential: enable state capability
credential: add an argument to keep state
http: add support for authtype and credential
docs: indicate new credential protocol fields
credential: add a field called "ephemeral"
credential: gate new fields on capability
credential: add a field for pre-encoded credentials
http: use new headers for each object request
remote-curl: reset headers on new request
credential: add an authtype field
Apply the rules that rewrite callers of "refs" interfaces to explicitly
pass `struct ref_store`. The resulting patch has been applied with the
`--whitespace=fix` option.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `for_each_fullref_in()` function is supposedly the ref-store-less
equivalent of `refs_for_each_fullref_in()`, but the latter has gained a
new parameter `exclude_patterns` over time. Bring these two functions
back in sync again by adding the parameter to the former function, as
well.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git-tag supports interpreting trailers from an annotated tag message,
using --list --format="%(trailers)". However, the available methods to
add a trailer to a tag message (namely -F or --editor) are not as
ergonomic.
In a previous patch, we moved git-commit's implementation of its
--trailer option to the trailer.h API. Let's use that new function to
teach git-tag the same --trailer option, emulating as much of
git-commit's behavior as much as possible.
Helped-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: John Passaro <john.a.passaro@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git-commit adds user trailers to the commit message by passing its
`--trailer` arguments to a child process running `git-interpret-trailers
--in-place`. This logic is broadly useful, not just for git-commit but
for other commands constructing message bodies (e.g. git-tag).
Let's move this logic from git-commit to a new function in the trailer
API, so that it can be re-used in other commands.
Helped-by: Patrick Steinhardt <ps@pks.im>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: John Passaro <john.a.passaro@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Replace git-commit's callback for --trailer with the standard
OPT_PASSTHRU_ARGV macro. The callback only adds its values to a strvec
and sanity-checks that `unset` is always false; both of these are
already implemented in the parse-option API.
Signed-off-by: John Passaro <john.a.passaro@gmail.com>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `refs_create_symref()` function is used to update/create a symref.
But it doesn't check the old target of the symref, if existing. It force
updates the symref. In this regard, the name `refs_create_symref()` is a
bit misleading. So let's rename it to `refs_update_symref()`. This is
akin to how 'git-update-ref(1)' also allows us to create apart from
update.
While we're here, rename the arguments in the function to clarify what
they actually signify and reduce confusion.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function `ref_transaction_update()` obtains ref information and
flags to create a `ref_update` and add them to the transaction at hand.
To extend symref support in transactions, we need to also accept the
old and new ref targets and process it. This commit adds the required
parameters to the function and modifies all call sites.
The two parameters added are `new_target` and `old_target`. The
`new_target` is used to denote what the reference should point to when
the transaction is applied. Some functions allow this parameter to be
NULL, meaning that the reference is not changed.
The `old_target` denotes the value the reference must have before the
update. Some functions allow this parameter to be NULL, meaning that the
old value of the reference is not checked.
We also update the internal function `ref_transaction_add_update()`
similarly to take the two new parameters.
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is possible to run git-shortlog(1) outside of a repository by passing
it output from git-log(1) via standard input. Obviously, as there is no
repository in that context, it is thus unsupported to pass any revisions
as arguments.
Regardless of that we still end up calling `setup_revisions()`. While
that works alright, it is somewhat strange. Furthermore, this is about
to cause problems when we unset the default object hash.
Refactor the code to only call `setup_revisions()` when we have a
repository. This is safe to do as we already verify that there are no
arguments when running outside of a repository anyway.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git-diff(1) command can be used outside repositories to diff two
files with each other. But even if there is no repository we will end up
hashing the files that we are diffing so that we can print the "index"
line:
```
diff --git a/a b/b
index 7898192..6178079 100644
--- a/a
+++ b/b
@@ -1 +1 @@
-a
+b
```
We implicitly use SHA1 to calculate the hash here, which is because
`the_repository` gets initialized with SHA1 during the startup routine.
We are about to stop doing this though such that `the_repository` only
ever has a hash function when it was properly initialized via a repo's
configuration.
To give full control to our users, we would ideally add a new switch to
git-diff(1) that allows them to specify the hash function when executed
outside of a repository. But for now, we only convert the code to make
this explicit such that we can stop setting the default hash algorithm
for `the_repository`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Verifying a bundle requires us to have a repository. This is encoded in
`verify_bundle()`, which will return an error if there is no repository.
We call `open_bundle()` before we call `verify_bundle()` though, which
already performs some verifications even though we may ultimately abort
due to a missing repository.
This is problematic because `open_bundle()` already reads the bundle
header and verifies that it contains a properly formatted hash. When
there is no repository we have no clue what hash function to expect
though, so we always end up assuming SHA1 here, which may or may not be
correct. Furthermore, we are about to stop initializing `the_hash_algo`
when there is no repository, which will lead to segfaults.
Check early on whether we have a repository to fix this issue.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We access `the_hash_algo` in git-blame(1) before we have executed
`parse_options_start()`, which may not be properly set up in case we
have no repository. This is fine for most of the part because all the
call paths that lead to it (git-blame(1), git-annotate(1) as well as
git-pick-axe(1)) specify `RUN_SETUP` and thus require a repository.
There is one exception though, namely when passing `-h` to print the
help. Here we will access `the_hash_algo` even if there is no repo.
This works fine right now because `the_hash_algo` gets sets up to point
to the SHA1 algorithm via `initialize_repository()`. But we're about to
stop doing this, and thus the code would lead to a `NULL` pointer
exception.
Prepare the code for this and only access `the_hash_algo` after we are
sure that there is a proper repository.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `--short=` option for git-rev-parse(1) allows the user to specify
to how many characters object IDs should be shortened to. The option is
broken though for SHA256 repositories because we set the maximum allowed
hash size to `the_hash_algo->hexsz` before we have even set up the repo.
Consequently, `the_hash_algo` will always be SHA1 and thus we truncate
every hash after at most 40 characters.
Fix this by accessing `the_hash_algo` only after we have set up the
repo.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* ps/the-index-is-no-more:
repository: drop `initialize_the_repository()`
repository: drop `the_index` variable
builtin/clone: stop using `the_index`
repository: initialize index in `repo_init()`
builtin: stop using `the_index`
t/helper: stop using `the_index`
We see too often that a range-diff added to format-patch output
shows too many "unmatched" patches. This is because the default
value for creation-factor is set to a relatively low value.
It may be justified for other uses (like you have a yet-to-be-sent
new iteration of your series, and compare it against the 'seen'
branch that has an older iteration, probably with the '--left-only'
option, to pick out only your patches while ignoring the others) of
"range-diff" command, but when the command is run as part of the
format-patch, the user _knows_ and expects that the patches in the
old and the new iterations roughly correspond to each other, so we
can and should use a much higher default.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Until now, `git config -h` would have printed help for the old-style
syntax. Now that all modes have proper subcommands though it is
preferable to instead display the subcommand help.
Drop the `NO_INTERNAL_HELP` flag to do so. While at it, drop the help
mismatch in t0450 and add the `--get-colorbool` option to the usage such
that git-config(1)'s synopsis and `git config -h` match.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new "edit" subcommand to git-config(1). Please refer to
preceding commits regarding the motivation behind this change.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new "remove-section" subcommand to git-config(1). Please
refer to preceding commits regarding the motivation behind this change.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new "rename-section" subcommand to git-config(1). Please
refer to preceding commits regarding the motivation behind this change.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new "unset" subcommand to git-config(1). Please refer to
preceding commits regarding the motivation behind this change.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new "set" subcommand to git-config(1). Please refer to
preceding commits regarding the motivation behind this change.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new "get" subcommand to git-config(1). Please refer to
preceding commits regarding the motivation behind this change.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While git-config(1) has several modes, those modes are not exposed with
subcommands but instead by specifying action flags like `--unset` or
`--list`. This user interface is not really in line with how our more
modern commands work, where it is a lot more customary to say e.g. `git
remote list`. Furthermore, to add to the confusion, git-config(1) also
allows the user to request modes implicitly by just specifying the
correct number of arguments. Thus, `git config foo.bar` will retrieve
the value of "foo.bar" while `git config foo.bar baz` will set it to
"baz".
Overall, this makes for a confusing interface that could really use a
makeover. It hurts discoverability of what you can do with git-config(1)
and is comparatively easy to get wrong. Converting the command to have
subcommands instead would go a long way to help address these issues.
One concern in this context is backwards compatibility. Luckily, we can
introduce subcommands without breaking backwards compatibility at all.
This is because all the implicit modes of git-config(1) require that the
first argument is a properly formatted config key. And as config keys
_must_ have a dot in their name, any value without a dot would have been
discarded by git-config(1) previous to this change. Thus, given that
none of the subcommands do have a dot, they are unambiguous.
Introduce the first such new subcommand, which is "git config list". To
retain backwards compatibility we only conditionally use subcommands and
will fall back to the old syntax in case no subcommand was detected.
This should help to transition to the new-style syntax until we
eventually deprecate and remove the old-style syntax.
Note that the way we handle this we're duplicating some functionality
across old and new syntax. While this isn't pretty, it helps us to
ensure that there really is no change in behaviour for the old syntax.
Amend tests such that we run them both with old and new style syntax.
As tests are now run twice, state from the first run may be still be
around in the second run and thus cause tests to fail. Add cleanup logic
as required to fix such tests.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Pull out function to handle the `--null` option, which we are about to
reuse in subsequent commits.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There's quite a bunch of options to git-config(1) that allow the user to
specify which config location to use when reading or writing config
options. The logic to handle this is thus by necessity also quite
involved.
Pull it out into a separate function so that we can reuse it in
subsequent commits which introduce proper subcommands.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git-config(1) command has various different modes which are
accessible via e.g. `--get-urlmatch` or `--unset-all`. These modes are
declared with `OPT_BIT()`, which causes two minor issues:
- The respective modes also have a negated form `--no-get-urlmatch`,
which is unintended.
- We have to manually handle exclusiveness of the modes.
Switch these options to instead use `OPT_CMDMODE()`, which is made
exactly for this usecase. Remove the now-unneeded check that only a
single mode is given, which is now handled by the parse-options
interface.
While at it, format optional placeholders for arguments to conform to
our style guidelines by using `[<placeholder>]`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `--fixed-value` option can be used to alter how the value-pattern
parameter is interpreted for the various actions of git-config(1). But
while it is an option, it is currently listed as part of the actions
group, which is wrong.
Move the option to the "Other" group, which hosts the various options
known to git-config(1).
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move around the option array. This will help us with a follow-up commit
that introduces subcommands to git-config(1).
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The ownership of memory returned when preparing a comment string is
quite intricate: when the returned value is different than the passed
value, then the caller is responsible to free the memory. This is quite
subtle, and it's even easier to miss because the returned value is in
fact a `const char *`.
Adapt the function to always return either `NULL` or a newly allocated
string. The function is called at most once per git-config(1), so it's
not like this micro-optimization really matters. Thus, callers are now
always responsible for freeing the value.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is the second and final preparatory commit for making the
trailer_info struct private to the trailer implementation.
Make trailer_info_get() do the actual work of allocating a new
trailer_info struct, and return a pointer to it. Because
parse_trailers() wraps around trailer_info_get(), it too can return this
pointer to the caller. From the trailer API user's perspective, the call
to trailer_info_new() can be replaced with parse_trailers(); do so in
interpret-trailers.
Because trailer_info_new() is no longer called by interpret-trailers,
remove this function from the trailer API.
With this change, we no longer allocate trailer_info on the stack ---
all uses of it are via a pointer where the actual data is always
allocated at runtime through trailer_info_new(). Make
trailer_info_release() free this dynamically allocated memory.
Finally, due to the way the function signatures of parse_trailers() and
trailer_info_get() have changed, update the callsites in
format_trailers_from_commit() and trailer_iterator_init() accordingly.
Helped-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Linus Arver <linus@ucla.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of directly accessing trailer_info members, access them
indirectly through new helper functions exposed by the trailer API.
This is the first of two preparatory commits which will allow us to
use the so-called "pimpl" (pointer to implementation) idiom for the
trailer API, by making the trailer_info struct private to the trailer
implementation (and thus hidden from the API).
Helped-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Linus Arver <linus@ucla.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
