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 ref_newer and its caller to use struct object_id instead of
unsigned char *.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJeff King <peff@peff.net>

Use struct object_id in three fields in struct ref and convert all the
necessary places that use it.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJeff King <peff@peff.net>

Instead of open-coding the function pop_commit() just call it.  This
makes the intent clearer and reduces code size.
Signed-off-by: NRene Scharfe <l.s.r@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The earlier rewrite f28e3ab2 (read_branches_file: simplify string handling)
of read_branches_file() lost an fclose() call. Put it back.

As on Windows files that are open cannot be removed, the leak manifests in
a failure of 'git remote rename origin origin' when the remote's URL is
specified in .git/branches/origin, because by the time that the command
attempts to remove this file, it is still open.
Signed-off-by: NJohannes Sixt <j6t@kdbg.org>
Acked-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In addition to dropping the magic number for the fixed-size
argv, we can also drop a fixed-length buffer and some
strcpy's into it.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The main motivation for this cleanup is to switch our
line-reading to a strbuf, which removes the use of a
fixed-size buffer (which limited the size of remote URLs).
Since we have the strbuf, we can make use of strbuf_rtrim().

While we're here, we can also simplify the parsing of each
line.  First, we can use skip_prefix() to avoid some magic
numbers.

But second, we can avoid splitting the parsing and actions
for each line into two stages. Right now we figure out which
type of line we have, set an int to a magic number,
skip any intermediate whitespace, and then act on
the resulting value based on the magic number.

Instead, let's factor the whitespace skipping into a
function. That lets us avoid the magic numbers and keep the
actions close to the parsing.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This function does a lot of manual string handling, and has
some unnecessary limits. This patch cleans up a number of
things:

  1. Drop the arbitrary 1000-byte limit on the size of the
     remote name (we do not have such a limit in any of the
     other remote-reading mechanisms).

  2. Replace fgets into a fixed-size buffer with a strbuf,
     eliminating any limits on the length of the URL.

  3. Replace manual whitespace handling with strbuf_trim
     (since we now have a strbuf). This also gets rid
     of a call to strcpy, and the confusing reuse of the "p"
     pointer for multiple purposes.

  4. We currently build up the refspecs over multiple strbuf
     calls. We do this to handle the fact that the URL "frag"
     may not be present. But rather than have multiple
     conditionals, let's just default "frag" to "master".
     This lets us format the refspecs with a single xstrfmt.
     It's shorter, and easier to see what the final string
     looks like.

     We also update the misleading comment in this area (the
     local branch is named after the remote name, not after
     the branch name on the remote side).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It's a common pattern to do:

  foo = xmalloc(strlen(one) + strlen(two) + 1 + 1);
  sprintf(foo, "%s %s", one, two);

(or possibly some variant with strcpy()s or a more
complicated length computation).  We can switch these to use
xstrfmt, which is shorter, involves less error-prone manual
computation, and removes many sprintf and strcpy calls which
make it harder to audit the code for real buffer overflows.
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>

In a triangular workflow, the place you pull from and the
place you push to may be different. As we have
branch_get_upstream for the former, this patch adds
branch_get_push for the latter (and as the former implements
@{upstream}, so will this implement @{push} in a future
patch).

Note that the memory-handling for the return value bears
some explanation. Some code paths require allocating a new
string, and some let us return an existing string. We should
provide a consistent interface to the caller, so it knows
whether to free the result or not.

We could do so by xstrdup-ing any existing strings, and
having the caller always free. But that makes us
inconsistent with branch_get_upstream, so we would prefer to
simply take ownership of the resulting string. We do so by
storing it inside the "struct branch", just as we do with
the upstream refname (in that case we compute it when the
branch is created, but there's no reason not to just fill
it in lazily in this case).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

After calling stat_tracking_info, callers often want to
print the name of the upstream branch (in addition to the
tracking count). To do this, they have to access
branch->merge->dst[0] themselves. This is not wrong, as the
return value from stat_tracking_info tells us whether we
have an upstream branch or not. But it is a bit leaky, as we
make an assumption about how it calculated the upstream
name.

Instead, let's add an out-parameter that lets the caller
know the upstream name we found.

As a bonus, we can get rid of the unusual tri-state return
from the function. We no longer need to use it to
differentiate between "no tracking config" and "tracking ref
does not exist" (since you can check the upstream_name for
that), so we can just use the usual 0/-1 convention for
success/error.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The error-diagnosis logic in branch_get_upstream was copied
straight from sha1_name.c in the previous commit. However,
because we check all error cases and upfront and then later
diagnose them, the logic is a bit tangled. In particular:

  - if branch->merge[0] is NULL, we may end up dereferencing
    it for an error message (in practice, it should never be
    NULL, so this is probably not a triggerable bug).

  - We may enter the code path because branch->merge[0]->dst
    is NULL, but we then start our error diagnosis by
    checking whether our local branch exists. But that is
    only relevant to diagnosing missing merge config, not a
    missing tracking ref; our diagnosis may hide the real
    problem.

Instead, let's just use a sequence of "if" blocks to check
for each error type, diagnose it, and return NULL.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When the previous commit introduced the branch_get_upstream
helper, there was one call-site that could not be converted:
the one in sha1_name.c, which gives detailed error messages
for each possible failure.

Let's teach the helper to optionally report these specific
errors. This lets us convert another callsite, and means we
can use the helper in other locations that want to give the
same error messages.

The logic and error messages come straight from sha1_name.c,
with the exception that we start each error with a lowercase
letter, as is our usual style (note that a few tests need
updated as a result).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

All of the information needed to find the @{upstream} of a
branch is included in the branch struct, but callers have to
navigate a series of possible-NULL values to get there.
Let's wrap that logic up in an easy-to-read helper.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Before the previous commit, we had to make sure that
read_config() was called before entering remote_get_1,
because we needed to pass pushremote_name by value. But now
that we pass a function, we can let remote_get_1 handle
loading the config itself, turning our wrappers into true
one-liners.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When remote.c loads its config, it records the
branch.*.pushremote for the current branch along with the
global remote.pushDefault value, and then binds them into a
single value: the default push for the current branch. We
then pass this value (which may be NULL) to remote_get_1
when looking up a remote for push.

This has a few downsides:

  1. It's confusing. The early-binding of the "current
     value" led to bugs like the one fixed by 98b406f3
     (remote: handle pushremote config in any order,
     2014-02-24). And the fact that pushremotes fall back to
     ordinary remotes is not explicit at all; it happens
     because remote_get_1 cannot tell the difference between
     "we are not asking for the push remote" and "there is
     no push remote configured".

  2. It throws away intermediate data. After read_config()
     finishes, we have no idea what the value of
     remote.pushDefault was, because the string has been
     overwritten by the current branch's
     branch.*.pushremote.

  3. It doesn't record other data. We don't note the
     branch.*.pushremote value for anything but the current
     branch.

Let's make this more like the fetch-remote config. We'll
record the pushremote for each branch, and then explicitly
compute the correct remote for the current branch at the
time of reading.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We'll want to use this logic as a fallback when looking up
the pushremote, so let's pull it out into its own function.

We don't technically need to make this available outside of
remote.c, but doing so will provide a consistent API with
pushremote_for_branch, which we will add later.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When we create each branch struct, we fill in the
"remote_name" field from the config, and then fill in the
actual "remote" field (with a "struct remote") based on that
name. However, it turns out that nobody really cares about
the latter field. The only two sites that access it at all
are:

  1. git-merge, which uses it to notice when the branch does
     not have a remote defined. But we can easily replace this
     with looking at remote_name instead.

  2. remote.c itself, when setting up the @{upstream} merge
     config. But we don't need to save the "remote" in the
     "struct branch" for that; we can just look it up for
     the duration of the operation.

So there is no need to have both fields; they are redundant
with each other (the struct remote contains the name, or you
can look up the struct from the name). It would be nice to
simplify this, especially as we are going to add matching
pushremote config in a future patch (and it would be nice to
keep them consistent).

So which one do we keep and which one do we get rid of?

If we had a lot of callers accessing the struct, it would be
more efficient to keep it (since you have to do a lookup to
go from the name to the struct, but not vice versa). But we
don't have a lot of callers; we have exactly one, so
efficiency doesn't matter. We can decide this based on
simplicity and readability.

And the meaning of the struct value is somewhat unclear. Is
it always the remote matching remote_name? If remote_name is
NULL (i.e., no per-branch config), does the struct fall back
to the "origin" remote, or is it also NULL? These questions
will get even more tricky with pushremotes, whose fallback
behavior is more complicated. So let's just store the name,
which pretty clearly represents the branch.*.remote config.
Any lookup or fallback behavior can then be implemented in
helper functions.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When we call branch_get() to lookup or create a "struct
branch", we make sure the "merge" field is filled in so that
callers can access it. But the conditions under which we do
so are a little confusing, and can lead to two funny
situations:

  1. If there's no branch.*.remote config, we cannot provide
     branch->merge (because it is really just an application
     of branch.*.merge to our remote's refspecs). But
     branch->merge_nr may be non-zero, leading callers to be
     believe they can access branch->merge (e.g., in
     branch_merge_matches and elsewhere).

     It doesn't look like this can cause a segfault in
     practice, as most code paths dealing with merge config
     will bail early if there is no remote defined. But it's
     a bit of a dangerous construct.

     We can fix this by setting merge_nr to "0" explicitly
     when we realize that we have no merge config. Note that
     merge_nr also counts the "merge_name" fields (which we
     _do_ have; that's how merge_nr got incremented), so we
     will "lose" access to them, in the sense that we forget
     how many we had. But no callers actually care; we use
     merge_name only while iteratively reading the config,
     and then convert it to the final "merge" form the first
     time somebody calls branch_get().

  2. We set up the "merge" field every time branch_get is
     called, even if it has already been done. This leaks
     memory.

     It's not a big deal in practice, since most code paths
     will access only one branch, or perhaps each branch
     only one time. But if you want to be pathological, you
     can leak arbitrary memory with:

       yes @{upstream} | head -1000 | git rev-list --stdin

     We can fix this by skipping setup when branch->merge is
     already non-NULL.

In addition to those two fixes, this patch pushes the "do we
need to setup merge?" logic down into set_merge, where it is
a bit easier to follow.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When we read the remote config from disk, we update a
default_remote_name variable if we see branch.*.remote
config for the current branch. This isn't wrong, or even all
that complicated, but it is a bit simpler (because it
reduces our overall state) to just lazily compute the
default when we need it.

The ulterior motive here is that the push config uses a
similar structure, and _is_ much more complicated as a
result. That will be simplified in a future patch, and it's
more readable if the logic for remotes and push-remotes
matches.

Note that we also used default_remote_name as a signal that
the remote config has been loaded; after this patch, we now
use an explicit flag.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

No external callers exist.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This replaces "x ? xstrdup(x) : NULL" with xstrdup_or_null(x).
The change is fairly mechanical, with the exception of
resolve_refdup, which can eliminate a temporary variable.

There are still a few hits grepping for "?.*xstrdup", but
these are of slightly different forms and cannot be
converted (e.g., "x ? xstrdup(x->foo) : NULL").
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The new name is more consistent with the names of other
string_list-related functions.
Suggested-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

resolve_ref_unsafe takes a boolean argument for reading (a nonexistent ref
resolves successfully for writing but not for reading).  Change this to be
a flags field instead, and pass the new constant RESOLVE_REF_READING when
we want this behaviour.

While at it, swap two of the arguments in the function to put output
arguments at the end.  As a nice side effect, this ensures that we can
catch callers that were unaware of the new API so they can be audited.

Give the wrapper functions resolve_refdup and read_ref_full the same
treatment for consistency.
Signed-off-by: NRonnie Sahlberg <sahlberg@google.com>
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When checking out a branch that is set to build on top of another
branch (often, a remote-tracking branch), "git checkout" reports how
your work relates to the other branch, e.g.

    Your branch is behind 'origin/master', and can be fast-forwarded.

Back when this feature was introduced, this was only done for
branches that build on remote-tracking branches, but 5e6e2b48 (Make
local branches behave like remote branches when --tracked,
2009-04-01) added support to give the same report for branches that
build on other local branches (i.e. branches whose branch.*.remote
variables are set to '.').  Unlike the support for the branches
building on remote-tracking branches, however, this did not take
into account the fact that branch.*.merge configuration is allowed
to record a shortened branch name.

When branch.*.merge is set to 'master' (not 'refs/heads/master'),
i.e. "my branch builds on the local 'master' branch", this caused
"git checkout" to report:

    Your branch is based on 'master', but the upstream is gone.

The upstream is our repository and is definitely not gone, so this
output is nonsense.

The fix is fairly obvious; just like the branch name is DWIMed when
"git pull" merges from the 'master' branch without complaint on such
a branch, the name of the branch the current branch builds upon
needs to be DWIMed the same way.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Make the code simpler and shorter by avoiding repetitive use of
string length variables and leaving memory allocation to strbuf
functions.
Signed-off-by: NRene Scharfe <l.s.r@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Even the documentation tells us:

	You should check if it returns any error (non-zero return
	code) and if it does not, you can start using get_revision()
	to do the iteration.

In preparation for this commit, I grepped all occurrences of
prepare_revision_walk and added error messages, when there were none.
Signed-off-by: NStefan Beller <stefanbeller@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Found by scan.coverity.com (Id: 1127809)
Signed-off-by: NStefan Beller <stefanbeller@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Remotes are stored as an array, so looking one up or adding one without
duplication is an O(n) operation.  Reading an entire config file full of
remotes is O(n^2) in the number of remotes.  For a repository with tens of
thousands of remotes, the running time can hit multiple minutes.

Hash tables are way faster.  So we add a hashmap from remote name to
struct remote and use it for all lookups.  The time to add a new remote to
a repo that already has 50,000 remotes drops from ~2 minutes to < 1
second.

We retain the old array of remotes so iterators proceed in config-file
order.
Signed-off-by: NPatrick Reynolds <patrick.reynolds@github.com>
Reviewed-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It's a common idiom to match a prefix and then skip past it
with strlen, like:

  if (starts_with(foo, "bar"))
	  foo += strlen("bar");

This avoids magic numbers, but means we have to repeat the
string (and there is no compiler check that we didn't make a
typo in one of the strings).

We can use skip_prefix to handle this case without repeating
ourselves.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In many parts of the code, we do an ugly and error-prone
malloc like:

  const char *fmt = "something %s";
  buf = xmalloc(strlen(foo) + 10 + 1);
  sprintf(buf, fmt, foo);

This makes the code brittle, and if we ever get the
allocation wrong, is a potential heap overflow. Let's
instead favor xstrfmt, which handles the allocation
automatically, and makes the code shorter and more readable.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert three cases of checking for a constant prefix using memcmp() to
starts_with().  This way there is no need for magic string length
constants and we avoid running over the end of the string should it be
shorter than the prefix.
Signed-off-by: NRene Scharfe <l.s.r@web.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

xcalloc() takes two arguments: the number of elements and their size.
parse_refspec_internal passes the arguments in reverse order, passing the
size of a refspec, followed by the number to allocate.

Rearrange them so they are in the correct order.
Signed-off-by: NBrian Gesiak <modocache@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJustin Lebar <jlebar@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We need to consider that a remote-tracking branch may match more than
one rhs of a fetch refspec. In such a case, it is not enough to stop at
the first match but look at all of the matches in order to determine
whether a head is stale.

To this goal, introduce a variant of query_refspecs which returns all of
the matching refspecs and loop over those answers to check for
staleness.
Signed-off-by: NCarlos Martín Nieto <cmn@elego.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When pushing, we do not even look at our push refspecs until
after we have made contact with the remote receive-pack and
gotten its list of refs. This means that we may go to some
work, including asking the user to log in, before realizing
we have simple errors like "git push origin matser".

We cannot catch all refspec problems, since fully evaluating
the refspecs requires knowing what the remote side has. But
we can do a quick sanity check of the local side and catch a
few simple error cases.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The match_explicit_lhs function has all of the logic
necessary to verify the refspecs without actually doing any
work. This patch lets callers pass a NULL "match" pointer to
indicate they want a "verify only" operation.

For the most part, we just need to avoid writing to the NULL
pointer. However, we also have to refactor the
try_explicit_object_name sub-function; it indicates success by
allocating and returning a new ref. Instead, we give it an
"out" parameter for the match and return a numeric status.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In preparation for being able to check the left-hand side of
our push refspecs separately, this pulls the examination of
them out into its own function. There should be no behavior
change.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>