Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When checkout dwim is added in [1], it is restricted to only dwim when
certain conditions are met and fall back to default checkout behavior
otherwise. It turns out falling back could be confusing. One of the
conditions to turn

    git checkout frotz

to

    git checkout -b frotz origin/frotz

is that frotz must not exist as a file. But when the user comes to
expect "git checkout frotz" to create the branch "frotz" and there
happens to be a file named "frotz", git's silently reverting "frotz"
file content is not helping. This is reported in Git mailing list [2]
and even used as an example of "Git is bad" elsewhere [3].

We normally try to do the right thing, but when there are multiple
"right things" to do, it's best to leave it to the user to decide.
Check this case, ask the user to to disambiguate:

- "git checkout -- foo" will check out path "foo"
- "git checkout foo --" will dwim and create branch "foo" [4]

For users who do not want dwim, use --no-guess. It's useless in this
particular case because "git checkout --no-guess foo --" will just
fail. But it could be used by scripts.

[1] 70c9ac2f (DWIM "git checkout frotz" to "git checkout -b frotz
    origin/frotz" - 2009-10-18)
[2] https://public-inbox.org/git/CACsJy8B2TVr1g+k+eSQ=pBEO3WN4_LtgLo9gpur8X7Z9GOFL_A@mail.gmail.com/
[3] https://news.ycombinator.com/item?id=18230655
[4] a047fafc (checkout: allow dwim for branch creation for "git
    checkout $branch --" - 2013-10-18)
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We added faster equality-comparison functions for hashes in
14438c44 (introduce hasheq() and oideq(), 2018-08-28). A
few topics were in-flight at the time, and can now be
converted. This covers all spots found by "make coccicheck"
in master (the coccicheck results were tweaked by hand for
style).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Using the more restrictive oideq() should, in the long run,
give the compiler more opportunities to optimize these
callsites. For now, this conversion should be a complete
noop with respect to the generated code.

The result is also perhaps a little more readable, as it
avoids the "zero is equal" idiom. Since it's so prevalent in
C, I think seasoned programmers tend not to even notice it
anymore, but it can sometimes make for awkward double
negations (e.g., we can drop a few !!oidcmp() instances
here).

This patch was generated almost entirely by the included
coccinelle patch. This mechanical conversion should be
completely safe, because we check explicitly for cases where
oidcmp() is compared to 0, which is what oideq() is doing
under the hood. Note that we don't have to catch "!oidcmp()"
separately; coccinelle's standard isomorphisms make sure the
two are treated equivalently.

I say "almost" because I did hand-edit the coccinelle output
to fix up a few style violations (it mostly keeps the
original formatting, but sometimes unwraps long lines).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Skip merging the commit, updating the index and working directory if and
only if we are creating a new branch via "git checkout -b <new_branch>."
Any other checkout options will still go through the former code path.

If sparse_checkout is on, require the user to manually opt in to this
optimzed behavior by setting the config setting checkout.optimizeNewBranch
to true as we will no longer update the skip-worktree bit in the index, nor
add/remove files in the working directory to reflect the current sparse
checkout settings.

For comparison, running "git checkout -b <new_branch>" on a large repo takes:

14.6 seconds - without this patch
0.3 seconds - with this patch
Signed-off-by: NBen Peart <Ben.Peart@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Make the match_patchspec API and friends take an index_state instead
of assuming the_index in dir.c. All external call sites are converted
blindly to keep the patch simple and retain current behavior.
Individual call sites may receive further updates to use the right
index instead of the_index.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Many messages will be marked for translation in the following
commits. This commit updates some of them to be more consistent and
reduce diff noise in those commits. Changes are

- keep the first letter of die(), error() and warning() in lowercase
- no full stop in die(), error() or warning() if it's single sentence
  messages
- indentation
- some messages are turned to BUG(), or prefixed with "BUG:" and will
  not be marked for i18n
- some messages are improved to give more information
- some messages are broken down by sentence to be i18n friendly
  (on the same token, combine multiple warning() into one big string)
- the trailing \n is converted to printf_ln if possible, or deleted
  if not redundant
- errno_errno() is used instead of explicit strerror()
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It has been observed that the time spent loading an index with a large
number of entries is partly dominated by malloc() calls. This change
is in preparation for using memory pools to reduce the number of
malloc() calls made to allocate cahce entries when loading an index.

Add an API to allocate and discard cache entries, abstracting the
details of managing the memory backing the cache entries. This commit
does actually change how memory is managed - this will be done in a
later commit in the series.

This change makes the distinction between cache entries that are
associated with an index and cache entries that are not associated with
an index. A main use of cache entries is with an index, and we can
optimize the memory management around this. We still have other cases
where a cache entry is not persisted with an index, and so we need to
handle the "transient" use case as well.

To keep the congnitive overhead of managing the cache entries, there
will only be a single discard function. This means there must be enough
information kept with the cache entry so that we know how to discard
them.

A summary of the main functions in the API is:

make_cache_entry: create cache entry for use in an index. Uses specified
                  parameters to populate cache_entry fields.

make_empty_cache_entry: Create an empty cache entry for use in an index.
                        Returns cache entry with empty fields.

make_transient_cache_entry: create cache entry that is not used in an
                            index. Uses specified parameters to populate
                            cache_entry fields.

make_empty_transient_cache_entry: create cache entry that is not used in
                                  an index. Returns cache entry with
                                  empty fields.

discard_cache_entry: A single function that knows how to discard a cache
                     entry regardless of how it was allocated.
Signed-off-by: NJameson Miller <jamill@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Teach make_cache_entry function to take object_id instead of a SHA-1.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add a repository argument to allow callers of
lookup_commit_reference_gently 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: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Introduce a checkout.defaultRemote setting which can be used to
designate a remote to prefer (via checkout.defaultRemote=origin) when
running e.g. "git checkout master" to mean origin/master, even though
there's other remotes that have the "master" branch.

I want this because it's very handy to use this workflow to checkout a
repository and create a topic branch, then get back to a "master" as
retrieved from upstream:

    (
        cd /tmp &&
        rm -rf tbdiff &&
        git clone git@github.com:trast/tbdiff.git &&
        cd tbdiff &&
        git branch -m topic &&
        git checkout master
    )

That will output:

    Branch 'master' set up to track remote branch 'master' from 'origin'.
    Switched to a new branch 'master'

But as soon as a new remote is added (e.g. just to inspect something
from someone else) the DWIMery goes away:

    (
        cd /tmp &&
        rm -rf tbdiff &&
        git clone git@github.com:trast/tbdiff.git &&
        cd tbdiff &&
        git branch -m topic &&
        git remote add avar git@github.com:avar/tbdiff.git &&
        git fetch avar &&
        git checkout master
    )

Will output (without the advice output added earlier in this series):

    error: pathspec 'master' did not match any file(s) known to git.

The new checkout.defaultRemote config allows me to say that whenever
that ambiguity comes up I'd like to prefer "origin", and it'll still
work as though the only remote I had was "origin".

Also adjust the advice.checkoutAmbiguousRemoteBranchName message to
mention this new config setting to the user, the full output on my
git.git is now (the last paragraph is new):

    $ ./git --exec-path=$PWD checkout master
    error: pathspec 'master' did not match any file(s) known to git.
    hint: 'master' matched more than one remote tracking branch.
    hint: We found 26 remotes with a reference that matched. So we fell back
    hint: on trying to resolve the argument as a path, but failed there too!
    hint:
    hint: If you meant to check out a remote tracking branch on, e.g. 'origin',
    hint: you can do so by fully qualifying the name with the --track option:
    hint:
    hint:     git checkout --track origin/<name>
    hint:
    hint: If you'd like to always have checkouts of an ambiguous <name> prefer
    hint: one remote, e.g. the 'origin' remote, consider setting
    hint: checkout.defaultRemote=origin in your config.

I considered splitting this into checkout.defaultRemote and
worktree.defaultRemote, but it's probably less confusing to break our
own rules that anything shared between config should live in core.*
than have two config settings, and I couldn't come up with a short
name under core.* that made sense (core.defaultRemoteForCheckout?).

See also 70c9ac2f ("DWIM "git checkout frotz" to "git checkout -b
frotz origin/frotz"", 2009-10-18) which introduced this DWIM feature
to begin with, and 4e853331 ("worktree: make add <path> <branch>
dwim", 2017-11-26) which added it to git-worktree.
Signed-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

As the "checkout" documentation describes:

    If <branch> is not found but there does exist a tracking branch in
    exactly one remote (call it <remote>) with a matching name, treat
    as equivalent to [...] <remote>/<branch.

This is a really useful feature. The problem is that when you add
another remote (e.g. a fork), git won't find a unique branch name
anymore, and will instead print this unhelpful message:

    $ git checkout master
    error: pathspec 'master' did not match any file(s) known to git

Now it will, on my git.git checkout, print:

    $ ./git --exec-path=$PWD checkout master
    error: pathspec 'master' did not match any file(s) known to git.
    hint: 'master' matched more than one remote tracking branch.
    hint: We found 26 remotes with a reference that matched. So we fell back
    hint: on trying to resolve the argument as a path, but failed there too!
    hint:
    hint: If you meant to check out a remote tracking branch on, e.g. 'origin',
    hint: you can do so by fully qualifying the name with the --track option:
    hint:
    hint:     git checkout --track origin/<name>

Note that the "error: pathspec[...]" message is still printed. This is
because whatever else checkout may have tried earlier, its final
fallback is to try to resolve the argument as a path. E.g. in this
case:

    $ ./git --exec-path=$PWD checkout master pu
    error: pathspec 'master' did not match any file(s) known to git.
    error: pathspec 'pu' did not match any file(s) known to git.

There we don't print the "hint:" implicitly due to earlier logic
around the DWIM fallback. That fallback is only used if it looks like
we have one argument that might be a branch.

I can't think of an intrinsic reason for why we couldn't in some
future change skip printing the "error: pathspec[...]" error. However,
to do so we'd need to pass something down to checkout_paths() to make
it suppress printing an error on its own, and for us to be confident
that we're not silencing cases where those errors are meaningful.

I don't think that's worth it since determining whether that's the
case could easily change due to future changes in the checkout logic.
Signed-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

There is no point in doing this right now, but in later change the
"ret" variable will be inspected. This change makes that meaningful
change smaller.
Signed-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Pass the previously added "num_matches" struct value up to the callers
of unique_tracking_name(). This will allow callers to optionally print
better error messages in a later change.
Signed-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Most --no- options do have some use, even if rarely to negate some
option that's specified in an alias.

These options --no-ours and --no-theirs however have no clear
semantics. If I specify "--ours --no-theirs", the second will reset
writeout stage and is equivalent of "--no-ours --no-theirs" which is
not that easy to see. Drop them. You can either switch from --ours to
--theirs and back but you can never negate them.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The strings allocated in `setup_unpack_trees_porcelain()` are never
freed. Provide a function `clear_unpack_trees_porcelain()` to do so and
call it where we use `setup_unpack_trees_porcelain()`. The only
non-trivial user is `unpack_trees_start()`, where we should place the
new call in `unpack_trees_finish()`.

We keep the string pointers in an array, mixing pointers to static
memory and memory that we allocate on the heap. We also keep several
copies of the individual pointers. So we need to make sure that we do
not free what we must not free and that we do not double-free. Let a
separate argv_array take ownership of all the strings we create so that
we can easily free them.

Zero the whole array of string pointers to make sure that we do not
leave any dangling pointers.

Note that we only take responsibility for the memory allocated in
`setup_unpack_trees_porcelain()` and not any other members of the
`struct unpack_trees_options`.
Helped-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NMartin Ågren <martin.agren@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This should make these functions easier to find and cache.h less
overwhelming to read.

In particular, this moves:
- read_object_file
- oid_object_info
- write_object_file

As a result, most of the codebase needs to #include object-store.h.
In this patch the #include is only added to files that would fail to
compile otherwise.  It would be better to #include wherever
identifiers from the header are used.  That can happen later
when we have better tooling for it.
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In anticipation of making trees load lazily, create a Coccinelle
script (contrib/coccinelle/commit.cocci) to ensure that all
references to the 'maybe_tree' member of struct commit are either
mutations or accesses through get_commit_tree() or
get_commit_tree_oid().

Apply the Coccinelle script to create the rest of the patch.
Signed-off-by: NDerrick Stolee <dstolee@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Using the commit-graph file to walk commit history removes the large
cost of parsing commits during the walk. This exposes a performance
issue: lookup_tree() takes a large portion of the computation time,
even when Git never uses those trees.

In anticipation of lazy-loading these trees, rename the 'tree' member
of struct commit to 'maybe_tree'. This serves two purposes: it hints
at the future role of possibly being NULL even if the commit has a
valid tree, and it allows for unambiguous transformation from simple
member access (i.e. commit->maybe_tree) to method access.
Signed-off-by: NDerrick Stolee <dstolee@microsoft.com>
Signed-off-by: NJunio 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: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert the declaration and definition of strbuf_add_unique_abbrev to
make it take a pointer to struct object_id.  Predeclare the struct in
strbuf.h, as cache.h includes strbuf.h before it declares the struct,
and otherwise the struct declaration would have the wrong scope.

Apply the following semantic patch, along with the standard object_id
transforms, to adjust the callers:

@@
expression E1, E2, E3;
@@
- strbuf_add_unique_abbrev(E1, E2.hash, E3);
+ strbuf_add_unique_abbrev(E1, &E2, E3);

@@
expression E1, E2, E3;
@@
- strbuf_add_unique_abbrev(E1, E2->hash, E3);
+ strbuf_add_unique_abbrev(E1, E2, E3);
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert the callback functions for read_tree_recursive to take a pointer
to struct object_id.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio 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: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The new completable options are:

--ignore-other-worktrees
--progress
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

--force option is most likely hidden from command line completion for
safety reasons. This is done by adding an extra flag
PARSE_OPT_NOCOMPLETE. Update OPT__FORCE() to accept additional
flags. Actual flag change comes later depending on individual
commands.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert the definition and declaration of write_sha1_file to
struct object_id and adjust usage of this function.

This commit also converts static function write_sha1_file_prepare, as it
is closely related.

Rename these functions to write_object_file and
write_object_file_prepare respectively.

Replace sha1_to_hex, hashcpy and hashclr with their oid equivalents
wherever possible.
Signed-off-by: NPatryk Obara <patryk.obara@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Teach long (normal) status format to respect the --no-ahead-behind
parameter and skip the possibly expensive ahead/behind computation
between the branch and the upstream.
Signed-off-by: NJeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The leak_pending flag is so awkward to use that multiple comments had to
be added around each occurrence.  We only use it for remembering the
commits whose marks we have to clear after checking if the old HEAD is
detached.  This is easy, though: We need to do that for the old commit,
the new one -- and for all refs.

Don't bother tracking exactly which commits need their flags cleared,
just nuke all we have in-core.  This change is safe because refs can
point at anything, so other program parts can't depend on any kept flags
anyway.  And since all refs are loaded we have to basically deal with
all commits anyway, so performance should not be negatively impacted.
Signed-off-by: NRene Scharfe <l.s.r@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

39bd6f72 (Allow checkout -B <current-branch> to update the current
branch, 2011-11-26) added 'clobber_head' (now, 'clobber_head_ok')
"before" 'track' as 'track' was closely related 'clobber_head' for
the purpose the commit wanted to achieve. Looking from the perspective
of how the arguments are used it turns out that 'clobber_head' is
more related to 'force' than it is to 'track'.

So, re-order the arguments to keep the related arguments close
to each other.
Signed-off-by: NKaartic Sivaraam <kaartic.sivaraam@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We do not want an ellipsis displayed following an (abbreviated) SHA-1
value.

The days when this was necessary to indicate the truncation to
lower-level Git commands and/or the user are bygone.

However, to ease the transition, the ellipsis will still be printed if
the user sets the environment variable GIT_PRINT_SHA1_ELLIPSIS to "yes".

Correct documentation with respect to what describe_detached_head prints
when GIT_PRINT_SHA1_ELLIPSIS is not set as indicated above.

Add tests for the old and new behaviour.
Signed-off-by: NAnn T Ropea <bedhanger@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Factor the functions out, so they can be re-used from other places.  In
particular these functions will be re-used in builtin/worktree.c to make
git worktree add dwim more.

While there add some docs to the function.
Signed-off-by: NThomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Switch the uses of empty_tree_oid and empty_blob_oid to use the
current_hash abstraction that represents the current hash algorithm in
use.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Even after working with this code for years, I still see this constant
name as "ref node ref". Rename it to make it's meaning clearer.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

All but two of the call sites already have parameters using the hash
parameter of struct object_id, so convert them to take a pointer to the
struct directly.  Also convert refs_read_refs_full, the underlying
implementation.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

All of the callers already pass the hash member of struct object_id, so
update them to pass a pointer to the struct directly,

This transformation was done with an update to declaration and
definition and the following semantic patch:

@@
expression E1, E2, E3, E4;
@@
- resolve_refdup(E1, E2, E3.hash, E4)
+ resolve_refdup(E1, E2, &E3, E4)

@@
expression E1, E2, E3, E4;
@@
- resolve_refdup(E1, E2, E3->hash, E4)
+ resolve_refdup(E1, E2, E3, E4)
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert update_ref, refs_update_ref, and write_pseudoref to use struct
object_id.  Update the existing callers as well.  Remove update_ref_oid,
as it is no longer needed.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Checking if a proposed name is appropriate for a branch is strictly
a subset of checking if we want to allow creating or updating a
branch with such a name.  The mysterious sounding 'attr_only'
parameter to validate_new_branchname() is used to switch the
function between these two roles.

Instead, split the function into two, and adjust the callers.  A new
helper validate_branchname() only checks the name and reports if the
branch already exists.

This loses one NEEDSWORK from the branch API.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>