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 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>

There is no longer any need to allocate and leak a `struct lock_file`.
The previous patch addressed an instance where we needed a minor tweak
alongside the trivial changes.

Deal with the remaining instances where we allocate and leak a struct
within a single function. Change them to have the `struct lock_file` on
the stack instead.

These instances were identified by running `git grep "^\s*struct
lock_file\s*\*"`.
Signed-off-by: NMartin Ågren <martin.agren@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add some UNLEAKs where we are about to return from `cmd_*`. UNLEAK the
variables in the same order as we've declared them. While addressing
`msg` in builtin/tag.c, convert the existing `strbuf_release()` calls as
well.
Signed-off-by: NMartin Ågren <martin.agren@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This allows us to get rid of several write-only variables.
Signed-off-by: NRene Scharfe <l.s.r@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Setting `leak_pending = 1` tells `prepare_revision_walk()` not to
release the `pending` array, and makes that the caller's responsibility.
See 4a43d374 (revision: add leak_pending flag, 2011-10-01) and
353f5657 (bisect: use leak_pending flag, 2011-10-01).

Commit 1da1e07c (clean up name allocation in prepare_revision_walk,
2014-10-15) fixed a memory leak in `prepare_revision_walk()` by
switching from `free()` to `object_array_clear()`. However, where we use
the `leak_pending`-mechanism, we're still only calling `free()`.

Use `object_array_clear()` instead. Copy some helpful comments from
353f5657 to the other callers that we update to clarify the memory
responsibilities, and to highlight that the commits are not affected
when we clear the array -- it is indeed correct to both tidy up the
commit flags and clear the object array.

Document `leak_pending` in revision.h to help future users get this
right.
Signed-off-by: NMartin Ågren <martin.agren@gmail.com>
Reviewed-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Gcc 7 adds -Wimplicit-fallthrough, which can warn when a
switch case falls through to the next case. The general idea
is that the compiler can't tell if this was intentional or
not, so you should annotate any intentional fall-throughs as
such, leaving it to complain about any unannotated ones.

There's a GNU __attribute__ which can be used for
annotation, but of course we'd have to #ifdef it away on
non-gcc compilers. Gcc will also recognize
specially-formatted comments, which matches our current
practice. Let's extend that practice to all of the
unannotated sites (which I did look over and verify that
they were behaving as intended).

Ideally in each case we'd actually give some reasons in the
comment about why we're falling through, or what we're
falling through to. And gcc does support that with
-Wimplicit-fallthrough=2, which relaxes the comment pattern
matching to anything that contains "fallthrough" (or a
variety of spelling variants). However, this isn't the
default for -Wimplicit-fallthrough, nor for -Wextra. In the
name of simplicity, it's probably better for us to support
the default level, which requires "fallthrough" to be the
only thing in the comment (modulo some window dressing like
"else" and some punctuation; see the gcc manual for the
complete set of patterns).

This patch suppresses all warnings due to
-Wimplicit-fallthrough. We might eventually want to add that
to the DEVELOPER Makefile knob, but we should probably wait
until gcc 7 is more widely adopted (since earlier versions
will complain about the unknown warning type).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Now that the submodule-config subsystem can lazily read the gitmodules
file we no longer need to explicitly pre-read the gitmodules by calling
'gitmodules_config()' so let's remove it.
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The 'submodule.update' config was historically used and respected by the
'submodule update' command because update handled a variety of different
ways it updated a submodule.  As we begin teaching other commands about
submodules it makes more sense for the different settings of
'submodule.update' to be handled by the individual commands themselves
(checkout, rebase, merge, etc) so it shouldn't be respected by the
native checkout command.

Also remove the overlaying of the repository's config (via using
'submodule_config()') from the commands which use the unpack-trees
logic (checkout, read-tree, reset).
Signed-off-by: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Some `clean` / `smudge` filters may require a significant amount of
time to process a single blob (e.g. the Git LFS smudge filter might
perform network requests). During this process the Git checkout
operation is blocked and Git needs to wait until the filter is done to
continue with the checkout.

Teach the filter process protocol, introduced in edcc8581 ("convert: add
filter.<driver>.process option", 2016-10-16), to accept the status
"delayed" as response to a filter request. Upon this response Git
continues with the checkout operation. After the checkout operation Git
calls "finish_delayed_checkout" which queries the filter for remaining
blobs. If the filter is still working on the completion, then the filter
is expected to block. If the filter has completed all remaining blobs
then an empty response is expected.

Git has a multiple code paths that checkout a blob. Support delayed
checkouts only in `clone` (in unpack-trees.c) and `checkout` operations
for now. The optimization is most effective in these code paths as all
files of the tree are processed.
Signed-off-by: NLars Schneider <larsxschneider@gmail.com>
Signed-off-by: NJunio 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: NBrandon Williams <bmwill@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Any command that understands '--recurse-submodules' can have its
default changed to true, by setting the new 'submodule.recurse'
option.

This patch includes read-tree/checkout/reset for working tree
manipulating commands. Later patches will cover other commands.
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The callback function is essentially duplicated 3 times. Remove all
of them and offer a new callback function, that lives in submodule.c

By putting the callback function there, we no longer need the function
'set_config_update_recurse_submodules', nor duplicate the global variable
in each builtin as well as submodule.c

In the three builtins we have different 2 ways how to load the .gitmodules
and config file, which are slightly different. git-checkout has to load
the submodule config all the time due to 23b4c7bc (checkout: Use
submodule.*.ignore settings from .git/config and .gitmodules, 2010-08-28)

git-reset and git-read-tree do not respect these diff settings, so loading
the submodule configuration is optional. Also put that into submodule.c
for code deduplication.
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The command line option for '--recurse-submodules' is implemented
using an OPTION_CALLBACK, which takes both the callback (that sets
the file static global variable) as well as passes the same file
static global variable to the option parsing machinery to assign it.
This is fixed in this commit by passing NULL as the variable. The
callback sets it instead
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

There has been a bug report by a corporate user that stated that
"spelling mistake of stash followed by a yes prints character 'y'
infinite times."

This analysis was false. When the spelling of a command contains
errors, the git program tries to help the user by providing candidates
which are close to the unexisting command. E.g Git prints the
following:

        git: 'stahs' is not a git command. See 'git --help'.
        Did you mean this?

        stash

and then exits.

The problem with this hint is that it is not formally indicated as an
hint and the user is in fact encouraged to reply to the question,
whereas the Git command is already finished.

The user was unlucky enough that it was the command he was looking
for, and replied "yes" on the command line, effectively launching the
`yes` program.

The initial error is that the Git programs, when launched in
command-line mode (without interaction) must not ask questions,
because these questions would normally require a user input as a reply
that they won't handle indeed. That's a source of confusion on UX
level.

To improve the general usability of the Git suite, the following rule
was applied:

if the sentence
 * appears in a non-interactive session
 * is printed last before exit
 * is a question addressing the user ("you")

the sentence is turned into affirmative and proposes the option.

The basic rewording of the question sentences has been extended to
other spots found in the source.

Requested at https://github.com/git/git-scm.com/issues/999 by rpai1
Signed-off-by: NJean-Noel Avila <jn.avila@free.fr>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When "git checkout -m" does an in-core three-way merge to carry
local modifications forward to check out a different branch, the
code forgot to free the updated contents it has in-core.
Noticed-by: NRené Scharfe <l.s.r@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert parse_tree_indirect to take a pointer to struct object_id.
Update all the callers.  This transformation was achieved using the
following semantic patch and manual updates to the declaration and
definition.  Update builtin/checkout.c manually as well, since it uses a
ternary expression not handled by the semantic patch.

@@
expression E1;
@@
- parse_tree_indirect(E1.hash)
+ parse_tree_indirect(&E1)

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

Rename this function and convert it to take a pointer to struct
object_id.

This is a prerequisite for converting get_reference, which is needed to
convert parse_object.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio 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: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This change addresses part of the NEEDSWORK comment above the code,
therefore the comment needs to be adjusted, too.

Discovered via Coverity.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If resolve_refdup() fails it returns NULL and possibly leaves its hash
output parameter untouched.  Make sure to use it only if the function
succeeded, in order to avoid accessing uninitialized memory.

Found with t/t2011-checkout-invalid-head.sh --valgrind.
Signed-off-by: NRene Scharfe <l.s.r@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Many functions which handle refs use a PATH_MAX-sized buffer
to do so. This is mostly reasonable as we have to write
loose refs into the filesystem, and at least on Linux the 4K
PATH_MAX is big enough that nobody would care. But:

  1. The static PATH_MAX is not always the filesystem limit.

  2. On other platforms, PATH_MAX may be much smaller.

  3. As we move to alternate ref storage, we won't be bound
     by filesystem limits.

Let's convert these to heap buffers so we don't have to
worry about truncation or size limits.

We may want to eventually constrain ref lengths for sanity
and to prevent malicious names, but we should do so
consistently across all platforms, and in a central place
(like the ref code).
Signed-off-by: NJeff King <peff@peff.net>

This exposes a flag to recurse into submodules
in builtin/checkout making use of the code implemented
in prior patches.

A new failure mode is introduced in the submodule
update library, as the directory/submodule conflict
is not solved in prior patches.
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When we parse "git checkout $NAME", we try to interpret
$NAME as a local branch-name. If it is, then we point HEAD
to that branch. Otherwise, we detach the HEAD at whatever
commit $NAME points to.

We do the interpretation by calling strbuf_branchname(), and
then blindly sticking "refs/heads/" on the front. This leads
to nonsense results when expansions like "@{upstream}" or
"@" point to something besides a local branch. We end up
with a local branch name like "refs/heads/origin/master" or
"refs/heads/HEAD".

Normally this has no user-visible effect because those
branches don't exist, and so we fallback to feeding the
result to get_sha1(), which resolves them correctly.

But as the new test in t3204 shows, there are corner cases
where the effect is observable, and we check out the wrong
local branch rather than detaching to the correct one.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio 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: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When core.logallrefupdates is true, we only create a new reflog for refs
that are under certain well-known hierarchies. The reason is that we
know that some hierarchies (like refs/tags) are not meant to change, and
that unknown hierarchies might not want reflogs at all (e.g., a
hypothetical refs/foo might be meant to change often and drop old
history immediately).

However, sometimes it is useful to override this decision and simply log
for all refs, because the safety and audit trail is more important than
the performance implications of keeping the log around.

This patch introduces a new "always" mode for the core.logallrefupdates
option which will log updates to everything under refs/, regardless
where in the hierarchy it is (we still will not log things like
ORIG_HEAD and FETCH_HEAD, which are known to be transient).
Based-on-patch-by: NJeff King <peff@peff.net>
Signed-off-by: NCornelius Weig <cornelius.weig@tngtech.com>
Reviewed-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NRene Scharfe <l.s.r@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Callers of the hold_locked_index() function pass 0 when they want to
prepare to write a new version of the index file without wishing to
die or emit an error message when the request fails (e.g. somebody
else already held the lock), and pass 1 when they want the call to
die upon failure.

This option is called LOCK_DIE_ON_ERROR by the underlying lockfile
API, and the hold_locked_index() function translates the paramter to
LOCK_DIE_ON_ERROR when calling the hold_lock_file_for_update().

Replace these hardcoded '1' with LOCK_DIE_ON_ERROR and stop
translating.  Callers other than the ones that are replaced with
this change pass '0' to the function; no behaviour change is
intended with this patch.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
---

Among the callers of hold_locked_index() that passes 0:

 - diff.c::refresh_index_quietly() at the end of "git diff" is an
   opportunistic update; it leaks the lockfile structure but it is
   just before the program exits and nobody should care.

 - builtin/describe.c::cmd_describe(),
   builtin/commit.c::cmd_status(),
   sequencer.c::read_and_refresh_cache() are all opportunistic
   updates and they are OK.

 - builtin/update-index.c::cmd_update_index() takes a lock upfront
   but we may end up not needing to update the index (i.e. the
   entries may be fully up-to-date), in which case we do not need to
   issue an error upon failure to acquire the lock.  We do diagnose
   and die if we indeed need to update, so it is OK.

 - wt-status.c::require_clean_work_tree() IS BUGGY.  It asks
   silence, does not check the returned value.  Compare with
   callsites like cmd_describe() and cmd_status() to notice that it
   is wrong to call update_index_if_able() unconditionally.

This function used to have the caller pass in the current
value of HEAD, in order to make sure we didn't clobber HEAD.
In 55c4a673, that logic moved to validate_new_branchname(),
which just resolves HEAD itself. The parameter to
create_branch is now unused.

Since we have to update and re-wrap the docstring describing
the parameters anyway, let's take this opportunity to break
it out into a list, which makes it easier to find the
parameters.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add a static initializer for struct checkout and use it throughout the
code base.  It's shorter, avoids a memset(3) call and makes sure the
base_dir member is initialized to a valid (empty) string.
Signed-off-by: NRene Scharfe <l.s.r@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The two functions in parse_branchname_arg(), verify_non_filename and
check_filename, need correct prefix in order to reconstruct the paths
and check for their existence. With NULL prefix, they just check paths
at top dir instead.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>