Convert struct diff_filespec's sha1 member to use a struct object_id
called "oid" instead.  The following Coccinelle semantic patch was used
to implement this, followed by the transformations in object_id.cocci:

@@
struct diff_filespec o;
@@
- o.sha1
+ o.oid.hash

@@
struct diff_filespec *p;
@@
- p->sha1
+ p->oid.hash
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The point of having a whitelist of command-line config
options to pass to submodules was two-fold:

  1. It prevented obvious nonsense like using core.worktree
     for multiple repos.

  2. It could prevent surprise when the user did not mean
     for the options to leak to the submodules (e.g.,
     http.sslverify=false).

For case 1, the answer is mostly "if it hurts, don't do
that". For case 2, we can note that any such example has a
matching inverted surprise (e.g., a user who meant
http.sslverify=true to apply everywhere, but it didn't).

So this whitelist is probably not giving us any benefit, and
is already creating a hassle as people propose things to put
on it. Let's just drop it entirely.

Note that we still need to keep a special code path for
"prepare the submodule environment", because we still have
to take care to pass through $GIT_CONFIG_PARAMETERS (and
block the rest of the repo-specific environment variables).

We can do this easily from within the submodule shell
script, which lets us drop the submodule--helper option
entirely (and it's OK to do so because as a "--" program, it
is entirely a private implementation detail).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Before 14111fc4 (git: submodule honor -c credential.* from
command line, 2016-02-29), it was sufficient for code which
spawned a process in a submodule to just set the child
process's "env" field to "local_repo_env" to clear the
environment of any repo-specific variables.

That commit introduced a more complicated procedure, in
which we clear most variables but allow through sanitized
config. For C code, we used that procedure only for cloning,
but not for any of the programs spawned by submodule.c. As a
result, things like "git fetch --recurse-submodules" behave
differently than "git clone --recursive"; the former will
not pass through the sanitized config.

We can fix this by using prepare_submodule_repo_env()
everywhere in submodule.c.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

These functions should be used by any code which spawns a
submodule process, which may happen in submodule.c (e.g.,
for spawning fetch). Let's move them there and make them
public so that submodule--helper can continue to use them.

Since they're now public, let's also provide a basic overview
of their intended use.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

By having the `submodule init` functionality in C, we can reference it
easier from other parts in the code in later patches. The code is split
up to have one function to initialize one submodule and a calling function
that takes care of the rest, such as argument handling and translating the
arguments to the paths of the submodules.

This is the first submodule subcommand that is fully converted to C
except for the usage string, so this is actually removing a call to
the `submodule--helper list` function, which is supposed to be used in
this transition. Instead we'll make a direct call to `module_list_compute`.

An explanation why we need to edit the prefixes in cmd_update in
git-submodule.sh in this patch:

By having no processing in the shell part, we need to convey the notion
of wt_prefix and prefix to the C parts, which former patches punted on
and did the processing of displaying path in the shell.

`wt_prefix` used to hold the path from the repository root to the current
directory, e.g. wt_prefix would be t/ if the user invoked the
`git submodule` command in ~/repo/t and ~repo is the GIT_DIR.

`prefix` used to hold the relative path from the repository root to the
operation, e.g. if you have recursive submodules, the shell script would
modify the `prefix` in each recursive step by adding the submodule path.

We will pass `wt_prefix` into the C helper via `git -C <dir>` as that
will setup git in the directory the user actually called git-submodule.sh
from. The `prefix` will be passed in via the `--prefix` option.

Having `prefix` and `wt_prefix` relative to the GIT_DIR of the
calling superproject is unfortunate with this patch as the C code doesn't
know about a possible recursion from a superproject via `submodule update
--init --recursive`.

To fix this, we change the meaning of `wt_prefix` to point to the current
project instead of the superproject and `prefix` to include any relative
paths issues in the superproject. That way `prefix` will become the leading
part for displaying paths and `wt_prefix` will be empty in recursive
calls for now.

The new notion of `wt_prefix` and `prefix` still allows us to reconstruct
the calling directory in the superproject by just traveling reverse of
`prefix`.
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This allows to configure fetching and updating in parallel
without having the command line option.

This moved the responsibility to determine how many parallel processes
to start from builtin/fetch to submodule.c as we need a way to communicate
"The user did not specify the number of parallel processes in the command
line options" in the builtin fetch. The submodule code takes care of
the precedence (CLI > config > default).
Reviewed-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Currently submodule.<name>.update is only handled by git-submodule.sh.
C code will start to need to make use of that value as more of the
functionality of git-submodule.sh moves into library code in C.

Add the update field to 'struct submodule' and populate it so it can
be read as sm->update or from sm->update_command.
Reviewed-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The expected way to pass data into the callback is to pass them via
the customizable callback pointer. The error reporting in
default_{start_failure, task_finished} is not user friendly enough, that
we want to encourage using the child data for such purposes.

Furthermore the struct child data is cleaned by the run-command API,
before we access them in the callbacks, leading to use-after-free
situations.
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If our size computation overflows size_t, we may allocate a
much smaller buffer than we expected and overflow it. It's
probably impossible to trigger an overflow in most of these
sites in practice, but it is easy enough convert their
additions and multiplications into overflow-checking
variants. This may be fixing real bugs, and it makes
auditing the code easier.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Rename git_config_set_or_die functions to git_config_set, leading
to the new default behavior of dying whenever a configuration
error occurs.

By now all callers that shall die on error have been transitioned
to the _or_die variants, thus making this patch a simple rename
of the functions.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The desired default behavior for `git_config_set` is to die
whenever an error occurs. Dying is the default for a lot of
internal functions when failures occur and is in this case the
right thing to do for most callers as otherwise we might run into
inconsistent repositories without noticing.

As some code may rely on the actual return values for
`git_config_set` we still require the ability to invoke these
functions without aborting. Rename the existing `git_config_set`
functions to `git_config_set_gently` to keep them available for
those callers.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When trying to connect a submodule with its corresponding
repository in '.git/modules' we try to set the core.worktree
setting in the submodule, which may fail due to an error
encountered in `git_config_set_in_file`.

The function is used in the git-mv command when trying to move a
submodule to another location. We already die when renaming a
file fails but do not pay attention to the case where updating
the connection between submodule and its repository fails. As
this leaves the repository in an inconsistent state, as well,
abort the program by dying early and presenting the failure to
the user.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This enables the work of the previous patches.
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In a later patch we enable parallel processing of submodules, this
only adds the possibility for it. So this change should not change
any user facing behavior.
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The "Pushing submodule <foo>" progress output correctly goes to
stderr, but "Fetching submodule <foo>" is going to stdout by
mistake.  Fix it to write to stderr.

Noticed while trying to implement a parallel submodule fetch.  When
this particular output line went to a different file descriptor, it
was buffered separately, resulting in wrongly interleaved output if
we copied it to the terminal naively.
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert all instances of get_object_hash to use an appropriate reference
to the hash member of the oid member of struct object.  This provides no
functional change, as it is essentially a macro substitution.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJeff King <peff@peff.net>

struct object is one of the major data structures dealing with object
IDs.  Convert it to use struct object_id instead of an unsigned char
array.  Convert get_object_hash to refer to the new member as well.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJeff King <peff@peff.net>

Convert most instances where the sha1 member of struct object is
dereferenced to use get_object_hash.  Most instances that are passed to
functions that have versions taking struct object_id, such as
get_sha1_hex/get_oid_hex, or instances that can be trivially converted
to use struct object_id instead, are not converted.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJeff King <peff@peff.net>

The add_submodule_odb function tries to add a submodule's
object store as an "alternate". It needs the existing list
to be initialized (from the objects/info/alternates file)
for two reasons:

  1. We look for duplicates with the existing alternate
     stores, but obviously this doesn't work if we haven't
     loaded any yet.

  2. We link our new entry into the list by prepending it to
     alt_odb_list. But we do _not_ modify alt_odb_tail.
     This variable starts as NULL, and is a signal to the
     alt_odb code that the list has not yet been
     initialized.

     We then call read_info_alternates on the submodule (to
     recursively load its alternates), which will try to
     append to that tail, assuming it has been initialized.
     This causes us to segfault if it is NULL.

This rarely comes up in practice, because we will have
initialized the alt_odb any time we do an object lookup. So
you can trigger this only when:

  - you try to access a submodule (e.g., a diff with
    diff.submodule=log)

  - the access happens before any other object has been
    accessed (e.g., because the diff is between the working
    tree and the index)

  - the submodule contains an alternates file (so we try to
    add an entry to the NULL alt_odb_tail)

To fix this, we just need to call prepare_alt_odb at the
start of the function (and if we have already initialized,
it is a noop).

Note that we can remove the prepare_alt_odb call from the
end. It is guaranteed to be a noop, since we will have
called it earlier.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When we are allocating a struct with a FLEX_ARRAY member, we
generally compute the size of the array and then sprintf or
strcpy into it. Normally we could improve a dynamic allocation
like this by using xstrfmt, but it doesn't work here; we
have to account for the size of the rest of the struct.

But we can improve things a bit by storing the length that
we use for the allocation, and then feeding it to xsnprintf
or memcpy, which makes it more obvious that we are not
writing more than the allocated number of bytes.

It would be nice if we had some kind of helper for
allocating generic flex arrays, but it doesn't work that
well:

 - the call signature is a little bit unwieldy:

      d = flex_struct(sizeof(*d), offsetof(d, path), fmt, ...);

   You need offsetof here instead of just writing to the
   end of the base size, because we don't know how the
   struct is packed (partially this is because FLEX_ARRAY
   might not be zero, though we can account for that; but
   the size of the struct may actually be rounded up for
   alignment, and we can't know that).

 - some sites do clever things, like over-allocating because
   they know they will write larger things into the buffer
   later (e.g., struct packed_git here).

So we're better off to just write out each allocation (or
add type-specific helpers, though many of these are one-off
allocations anyway).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Functions which directly operate submodule's object database do not
handle the case when the submodule is linked worktree (which are
introduced in c7b3a3d2). Instead of fixing the path calculation use
already existing strbuf_git_path_submodule() function without changing
overall behaviour. Then it will be possible to modify only that function
whenever we need to change real location of submodule's repository
content.
Helped-by: NJeff King <peff@peff.net>
Signed-off-by: NMax Kirillov <max@max630.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

All of the callsites covered by this change call write_file() or
write_file_gently() to create a one-liner file.  Drop the caller
supplied LF and let these callees to append it as necessary.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

All callers except three passed 1 for the "fatal" parameter to ask
this function to die upon error, but to a casual reader of the code,
it was not all obvious what that 1 meant.  Instead, split the
function into two based on a common write_file_v() that takes the
flag, introduce write_file_gently() as a new way to attempt creating
a file without dying on error, and make three callers to call it.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We should not die when reading the submodule config cache since the
user might not be able to get out of that situation when the
configuration is part of the history.

We should handle this condition later when the value is about to be
used.
Signed-off-by: NHeiko Voigt <hvoigt@hvoigt.net>
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We remove the extracted functions and directly parse into and read out
of the cache. This allows us to have one unified way of accessing
submodule configuration values specific to single submodules. Regardless
whether we need to access a configuration from history or from the
worktree.
Signed-off-by: NHeiko Voigt <hvoigt@hvoigt.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This is one step towards using the new configuration API. We just
extract these functions to make replacing the actual code easier.
Signed-off-by: NHeiko Voigt <hvoigt@hvoigt.net>
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In a superproject some commands need to interact with submodules. They
need to query values from the .gitmodules file either from the worktree
of from certain revisions. At the moment this is quite hard since a
caller would need to read the .gitmodules file from the history and then
parse the values. We want to provide an API for this so we have one
place to get values from .gitmodules from any revision (including the
worktree).

The API is realized as a cache which allows us to lazily read
.gitmodules configurations by commit into a runtime cache which can then
be used to easily lookup values from it. Currently only the values for
path or name are stored but it can be extended for any value needed.

It is expected that .gitmodules files do not change often between
commits. Thats why we lookup the .gitmodules sha1 from a commit and then
either lookup an already parsed configuration or parse and cache an
unknown one for each sha1. The cache is lazily build on demand for each
requested commit.

This cache can be used for all purposes which need knowledge about
submodule configurations. Example use cases are:

 * Recursive submodule checkout needs to lookup a submodule name from
   its path when a submodule first appears. This needs be done before
   this configuration exists in the worktree.

 * The implementation of submodule support for 'git archive' needs to
   lookup the submodule name to generate the archive when given a
   revision that is not checked out.

 * 'git fetch' when given the --recurse-submodules=on-demand option (or
   configuration) needs to lookup submodule names by path from the
   database rather than reading from the worktree. For new submodule it
   needs to lookup the name from its path to allow cloning new
   submodules into the .git folder so they can be checked out without
   any network interaction when the user does a checkout of that
   revision.
Signed-off-by: NHeiko Voigt <hvoigt@hvoigt.net>
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In preparation for adding date modes that may carry extra
information beyond the mode itself, this patch converts the
date_mode enum into a struct.

Most of the conversion is fairly straightforward; we pass
the struct as a pointer and dereference the type field where
necessary. Locations that declare a date_mode can use a "{}"
constructor.  However, the tricky case is where we use the
enum labels as constants, like:

  show_date(t, tz, DATE_NORMAL);

Ideally we could say:

  show_date(t, tz, &{ DATE_NORMAL });

but of course C does not allow that. Likewise, we cannot
cast the constant to a struct, because we need to pass an
actual address. Our options are basically:

  1. Manually add a "struct date_mode d = { DATE_NORMAL }"
     definition to each caller, and pass "&d". This makes
     the callers uglier, because they sometimes do not even
     have their own scope (e.g., they are inside a switch
     statement).

  2. Provide a pre-made global "date_normal" struct that can
     be passed by address. We'd also need "date_rfc2822",
     "date_iso8601", and so forth. But at least the ugliness
     is defined in one place.

  3. Provide a wrapper that generates the correct struct on
     the fly. The big downside is that we end up pointing to
     a single global, which makes our wrapper non-reentrant.
     But show_date is already not reentrant, so it does not
     matter.

This patch implements 3, along with a minor macro to keep
the size of the callers sane.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Change typedef each_ref_fn to take a "const struct object_id *oid"
parameter instead of "const unsigned char *sha1".

To aid this transition, implement an adapter that can be used to wrap
old-style functions matching the old typedef, which is now called
"each_ref_sha1_fn"), and make such functions callable via the new
interface. This requires the old function and its cb_data to be
wrapped in a "struct each_ref_fn_sha1_adapter", and that object to be
used as the cb_data for an adapter function, each_ref_fn_adapter().

This is an enormous diff, but most of it consists of simple,
mechanical changes to the sites that call any of the "for_each_ref"
family of functions. Subsequent to this change, the call sites can be
rewritten one by one to use the new interface.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Call file_exists() instead of open-coding it.  That's shorter, simpler
and the intent becomes clearer.
Signed-off-by: NRene Scharfe <l.s.r@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In is_submodule_commit_present, we call run_command followed
by a pipe read, which is prone to deadlock. It is unlikely
to happen in this case, as rev-list should never produce
more than a single line of output, but it does not hurt to
avoid an anti-pattern (and using the helper simplifies the
setup and cleanup).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This fixes common problems in these code about error handling,
forgetting to close the file handle after fprintf() fails, or not
printing out the error string..
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The callers of get_merge_bases() can choose to leave object flags
used during the merge-base traversal by passing cleanup=0 as a
parameter, but in practice a very few callers can afford to do so
(namely, "git merge-base"), as they need to compute merge base in
preparation for other processing of their own and they need to see
the object without contaminate flags.

Change the function signature of get_merge_bases_many() and
get_merge_bases() to drop the cleanup parameter, so that the
majority of the callers do not have to say ", 1" at the end.

Give a new get_merge_bases_many_dirty() API to support only a few
callers that know they do not need to spend cycles cleaning up the
object flags.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Most struct child_process variables are cleared using memset first after
declaration.  Provide a macro, CHILD_PROCESS_INIT, that can be used to
initialize them statically instead.  That's shorter, doesn't require a
function call and is slightly more readable (especially given that we
already have STRBUF_INIT, ARGV_ARRAY_INIT etc.).
Helped-by: NJohannes Sixt <j6t@kdbg.org>
Signed-off-by: NRene Scharfe <l.s.r@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Using memset and then manually setting values of the string-list
members is not future proof as the internal representation of
string-list may change any time.
Use `string_list_init()` or STRING_LIST_INIT_* macros instead of
memset.
Signed-off-by: NTanay Abhra <tanayabh@gmail.com>
Reviewed-by: NMatthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Use the ARRAY_SIZE macro to get the number
of elements in an array.
Signed-off-by: NElia Pinto <gitter.spiros@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Leaving only the function definitions and declarations so that any
new topic in flight can still make use of the old functions, replace
existing uses of the prefixcmp() and suffixcmp() with new API
functions.

The change can be recreated by mechanically applying this:

    $ git grep -l -e prefixcmp -e suffixcmp -- \*.c |
      grep -v strbuf\\.c |
      xargs perl -pi -e '
        s|!prefixcmp\(|starts_with\(|g;
        s|prefixcmp\(|!starts_with\(|g;
        s|!suffixcmp\(|ends_with\(|g;
        s|suffixcmp\(|!ends_with\(|g;
      '

on the result of preparatory changes in this series.
Signed-off-by: NChristian Couder <chriscool@tuxfamily.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Commit 5fee9952 introduced the stage_updated_gitmodules() function to
add submodule configuration updates to the index. It assumed that even
after calling remove_cache_entry_at() the same cache entry would still be
valid. This was true in the old days, as cache entries could never be
freed, but that is not so sure in the present as there is ongoing work to
free removed cache entries, which makes this code segfault.

Fix that by calling add_file_to_cache() instead of open coding it. Also
remove the "could not find .gitmodules in index" warning, as that won't
happen in regular use cases (and by then just silently adding it to the
index we do the right thing).

Thanks-to: Karsten Blees <karsten.blees@gmail.com>
Signed-off-by: NJens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Git fails due to a segmentation fault if a submodule path is empty.
Here is an example .gitmodules that will cause a segmentation fault:

    [submodule "foo-module"]
      path
      url = http://host/repo.git
    $ git status
    Segmentation fault (core dumped)

This is because the parsing of "submodule.*.path" is not prepared to
see a value-less "true" and assumes that the value is always
non-NULL (parsing of "ignore" has the same problem).

Fix it by checking the NULL-ness of value and complain with
config_error_nonbool().
Signed-off-by: NJharrod LaFon <jlafon@eyesopen.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>