Update the build dependency so that an update to /usr/bin/perl
etc. result in recomputation of perl.mak file.

* ab/regen-perl-mak-with-different-perl:
  perl: regenerate perl.mak if perl -V changes

"git diff --submodule=diff" learned to work better in a project
with a submodule that in turn has its own submodules.

* sb/show-diff-for-submodule-in-diff-fix:
  diff: submodule inline diff to initialize env array.

Doc update.

* qp/bisect-docfix:
  git-bisect.txt: add missing word

Doc update.

* mm/ls-files-s-doc:
  Documentation: document elements in "ls-files -s" output in order

Update error handling for codepath that deals with corrupt loose
objects.

* jk/loose-object-info-report-error:
  index-pack: detect local corruption in collision check
  sha1_loose_object_info: return error for corrupted objects

Code cleanup.

* jc/bs-t-is-not-a-tab-for-sed:
  contrib/git-resurrect.sh: do not write \t for HT in sed scripts

Code cleanup.

* jc/unused-symbols:
  remote.[ch]: parse_push_cas_option() can be static

Code clean-up.

* jk/snprintf-cleanups:
  daemon: use an argv_array to exec children
  gc: replace local buffer with git_path
  transport-helper: replace checked snprintf with xsnprintf
  convert unchecked snprintf into xsnprintf
  combine-diff: replace malloc/snprintf with xstrfmt
  replace unchecked snprintf calls with heap buffers
  receive-pack: print --pack-header directly into argv array
  name-rev: replace static buffer with strbuf
  create_branch: use xstrfmt for reflog message
  create_branch: move msg setup closer to point of use
  avoid using mksnpath for refs
  avoid using fixed PATH_MAX buffers for refs
  fetch: use heap buffer to format reflog
  tag: use strbuf to format tag header
  diff: avoid fixed-size buffer for patch-ids
  odb_mkstemp: use git_path_buf
  odb_mkstemp: write filename into strbuf
  do not check odb_mkstemp return value for errors

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Define a new task in .travis.yml that triggers a test session on
Windows run elsewhere.

* ls/travis-relays-for-windows-ci:
  travis-ci: build and test Git on Windows

Code cleanup.

* cc/untracked:
  update-index: fix xgetcwd() related memory leak

The default behaviour of "git log" in an interactive session has
been changed to enable "--decorate".

* ah/log-decorate-default-to-auto:
  log: if --decorate is not given, default to --decorate=auto

"git tag/branch/for-each-ref" family of commands long allowed to
filter the refs by "--contains X" (show only the refs that are
descendants of X), "--merged X" (show only the refs that are
ancestors of X), "--no-merged X" (show only the refs that are not
ancestors of X).  One curious omission, "--no-contains X" (show
only the refs that are not descendants of X) has been added to
them.

* ab/ref-filter-no-contains:
  tag: add tests for --with and --without
  ref-filter: reflow recently changed branch/tag/for-each-ref docs
  ref-filter: add --no-contains option to tag/branch/for-each-ref
  tag: change --point-at to default to HEAD
  tag: implicitly supply --list given another list-like option
  tag: change misleading --list <pattern> documentation
  parse-options: add OPT_NONEG to the "contains" option
  tag: add more incompatibles mode tests
  for-each-ref: partly change <object> to <commit> in help
  tag tests: fix a typo in a test description
  tag: remove a TODO item from the test suite
  ref-filter: add test for --contains on a non-commit
  ref-filter: make combining --merged & --no-merged an error
  tag doc: reword --[no-]merged to talk about commits, not tips
  tag doc: split up the --[no-]merged documentation
  tag doc: move the description of --[no-]merged earlier

David reported:
> When I try to run `git diff --submodule=diff` in a submodule which has
> it's own submodules that have changes I get the error: fatal: bad
> object.

This happens, because we do not properly initialize the environment
in which the diff is run in the submodule. That means we inherit the
environment from the main process, which sets environment variables.
(Apparently we do set environment variables which we do not set
when not in a submodules, i.e. the .git directory is linked)

This commit, just like fd47ae6a (diff: teach diff to display
submodule difference with an inline diff, 2016-08-31) introduces bad
test code (i.e. hard coded hash values), which will be cleanup up in
a later patch.
Reported-by: NDavid Parrish <daveparrish@gmail.com>
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NQuentin Pradet <quentin.pradet@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

List the fields in order of appearance in the command output.
Signed-off-by: NMostyn Bramley-Moore <mostyn@antipode.se>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When we notice that we have a local copy of an incoming
object, we compare the two objects to make sure we haven't
found a collision. Before we get to the actual object
bytes, though, we compare the type and size from
sha1_object_info().

If our local object is corrupted, then the type will be
OBJ_BAD, which obviously will not match the incoming type,
and we'll report "SHA1 COLLISION FOUND" (with capital
letters and everything). This is confusing, as the problem
is not a collision but rather local corruption. We should
report that instead (just like we do if reading the rest of
the object content fails a few lines later).

Note that we _could_ just ignore the error and mark it as a
non-collision. That would let you "git fetch" to replace a
corrupted object. But it's not a very reliable method for
repairing a repository. The earlier want/have negotiation
tries to get the other side to omit objects we already have,
and it would not realize that we are "missing" this
corrupted object. So we're better off complaining loudly
when we see corruption, and letting the user take more
drastic measures to repair (like making a full clone
elsewhere and copying the pack into place).

Note that the test sets transfer.unpackLimit in the
receiving repository so that we use index-pack (which is
what does the collision check). Normally for such a small
push we'd use unpack-objects, which would simply try to
write the loose object, and discard the new one when we see
that there's already an old one.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When sha1_loose_object_info() finds that a loose object file
cannot be stat(2)ed or mmap(2)ed, it returns -1 to signal an
error to the caller.  However, if it found that the loose
object file is corrupt and the object data cannot be used
from it, it stuffs OBJ_BAD into "type" field of the
object_info, but returns zero (i.e., success), which can
confuse callers.

This is due to 052fe5ea (sha1_loose_object_info: make type
lookup optional, 2013-07-12), which switched the return to a
strict success/error, rather than returning the type (but
botched the return).

Callers of regular sha1_object_info() don't notice the
difference, as that function returns the type (which is
OBJ_BAD in this case). However, direct callers of
sha1_object_info_extended() see the function return success,
but without setting any meaningful values in the object_info
struct, leading them to access potentially uninitialized
memory.

The easiest way to see the bug is via "cat-file -s", which
will happily ignore the corruption and report whatever
value happened to be in the "size" variable.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Just like we did in 0d1d6e50 ("t/t7003: replace \t with literal tab
in sed expression", 2010-08-12), avoid writing "\t" for HT in sed
scripts, which is not portable.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Since 068c77a5 ("builtin/send-pack.c: use parse_options API",
2015-08-19), there is no external user of this helper function.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Our struct child_process already has its own argv_array.
Let's use that to avoid having to format options into
separate buffers.

Note that we'll need to declare the child process outside of
the run_service_command() helper to do this. But that opens
up a further simplification, which is that the helper can
append to our argument list, saving each caller from
specifying "." manually.
Signed-off-by: NJeff King <peff@peff.net>

We probe the "17/" loose object directory for auto-gc, and
use a local buffer to format the path. We can just use
git_path() for this. It handles paths of any length
(reducing our error handling). And because we feed the
result straight to a system call, we can just use the static
variant.

Note that git_path also knows the string "objects/" is
special, and will replace it with git_object_directory()
when necessary.

Another alternative would be to use sha1_file_name() for the
pretend object "170000...", but that ends up being more
hassle for no gain, as we have to truncate the final path
component.
Signed-off-by: NJeff King <peff@peff.net>

We can use xsnprintf to do our truncation check with less
code. The error message isn't as specific, but the point is
that this isn't supposed to trigger in the first place
(because our buffer is big enough to handle any int).
Signed-off-by: NJeff King <peff@peff.net>

These calls to snprintf should always succeed, because their
input is small and fixed. Let's use xsnprintf to make sure
this is the case (and to make auditing for actual truncation
easier).

These could be candidates for turning into heap buffers, but
they fall into a few broad categories that make it not worth
doing:

  - formatting single numbers is simple enough that we can
    see the result should fit

  - the size of a sha1 is likewise well-known, and I didn't
    want to cause unnecessary conflicts with the ongoing
    process to convert these constants to GIT_MAX_HEXSZ

  - the interface for curl_errorstr is dictated by curl
Signed-off-by: NJeff King <peff@peff.net>

There's no need to use the magic "100" when a strbuf can do
it for us.
Signed-off-by: NJeff King <peff@peff.net>

We'd prefer to avoid unchecked snprintf calls because
truncation can lead to unexpected results.

These are all cases where truncation shouldn't ever happen,
because the input to snprintf is fixed in size. That makes
them candidates for xsnprintf(), but it's simpler still to
just use the heap, and then nobody has to wonder if "100" is
big enough.

We'll use xstrfmt() where possible, and a strbuf when we need
the resulting size or to reuse the same buffer in a loop.
Signed-off-by: NJeff King <peff@peff.net>

After receive-pack reads the pack header from the client, it
feeds the already-read part to index-pack and unpack-objects
via their --pack-header command-line options.  To do so, we
format it into a fixed buffer, then duplicate it into the
child's argv_array.

Our buffer is long enough to handle any possible input, so
this isn't wrong. But it's more complicated than it needs to
be; we can just argv_array_pushf() the final value and avoid
the intermediate copy. This drops the magic number and is
more efficient, too.

Note that we need to push to the argv_array in order, which
means we can't do the push until we are in the "unpack-objects
versus index-pack" conditional.  Rather than duplicate the
slightly complicated format specifier, I pushed it into a
helper function.
Signed-off-by: NJeff King <peff@peff.net>

When name-rev needs to format an actual name, we do so into
a fixed-size buffer. That includes the actual ref tip, as
well as any traversal information. Since refs can exceed
1024 bytes, this means you can get a bogus result. E.g.,
doing:

   git tag $(perl -e 'print join("/", 1..1024)')
   git describe --contains HEAD^

results in ".../282/283", when it should be
".../1023/1024~1".

We can solve this by using a heap buffer. We'll use a
strbuf, which lets us write into the same buffer from our
loop without having to reallocate.
Signed-off-by: NJeff King <peff@peff.net>

We generate a reflog message that contains some fixed text
plus a branch name, and use a buffer of size PATH_MAX + 20.
This mostly works if you assume that refnames are shorter
than PATH_MAX, but:

  1. That's not necessarily true. PATH_MAX is not always the
     filesystem's limit.

  2. The "20" is not sufficiently large for the fixed text
     anyway.

Let's just switch to a heap buffer so we don't have to even
care.
Signed-off-by: NJeff King <peff@peff.net>

In create_branch() we write the reflog msg into a buffer in
the main function, but then use it only inside a
conditional. If you carefully follow the logic, you can
confirm that we never use the buffer uninitialized nor write
when it would not be used. But we can make this a lot more
obvious by simply moving the write step inside the
conditional.
Signed-off-by: NJeff King <peff@peff.net>

Like the previous commit, we'd like to avoid the assumption
that refs fit into PATH_MAX-sized buffers. These callsites
have an extra twist, though: they write the refnames using
mksnpath. This does two things beyond a regular snprintf:

  1. It quietly writes "/bad-path/" when truncation occurs.
     This saves the caller having to check the error code,
     but if you aren't actually feeding the result to a
     system call (and we aren't here), it's questionable.

  2. It calls cleanup_path(), which removes leading
     instances of "./".  That's questionable when dealing
     with refnames, as we could silently canonicalize a
     syntactically bogus refname into a valid one.

Let's convert each case to use a strbuf. This is preferable
to xstrfmt() because we can reuse the same buffer as we
loop.
Signed-off-by: NJeff King <peff@peff.net>

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>

Part of the reflog content comes from the environment, which
can be much larger than our fixed buffer. Let's use a heap
buffer so we avoid truncating it.
Signed-off-by: NJeff King <peff@peff.net>

We format the tag header into a fixed 1024-byte buffer. But
since the tag-name and tagger ident can be arbitrarily
large, we may unceremoniously die with "tag header too big".
Let's just use a strbuf instead.

Note that it looks at first glance like we can just format
this directly into the "buf" strbuf where it will ultimately
go. But that buffer may already contain the tag message, and
we have no easy way to prepend formatted data to a strbuf
(we can only splice in an already-generated buffer). This
isn't a performance-critical path, so going through an extra
buffer isn't a big deal.
Signed-off-by: NJeff King <peff@peff.net>

To generate a patch id, we format the diff header into a
fixed-size buffer, and then feed the result to our sha1
computation. The fixed buffer has size '4*PATH_MAX + 20',
which in theory accommodates the four filenames plus some
extra data. Except:

  1. The filenames may not be constrained to PATH_MAX. The
     static value may not be a real limit on the current
     filesystem. Moreover, we may compute patch-ids for
     names stored only in git, without touching the current
     filesystem at all.

  2. The 20 bytes is not nearly enough to cover the
     extra content we put in the buffer.

As a result, the data we feed to the sha1 computation may be
truncated, and it's possible that a commit with a very long
filename could erroneously collide in the patch-id space
with another commit. For instance, if one commit modified
"really-long-filename/foo" and another modified "bar" in the
same directory.

In practice this is unlikely. Because the filenames are
repeated, and because there's a single cutoff at the end of
the buffer, the offending filename would have to be on the
order of four times larger than PATH_MAX.

We could fix this by moving to a strbuf. However, we can
observe that the purpose of formatting this in the first
place is to feed it to git_SHA1_Update(). So instead, let's
just feed each part of the formatted string directly. This
actually ends up more readable, and we can even factor out
some duplicated bits from the various conditional branches.

Technically this may change the output of patch-id for very
long filenames, but it's not worth making an exception for
this in the --stable output. It was a bug, and one that only
affected an unlikely set of paths.  And anyway, the exact
value would have varied from platform to platform depending
on the value of PATH_MAX, so there is no "stable" value.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Build fix.

* jk/make-coccicheck-detect-errors:
  Makefile: detect errors in running spatch

"git receive-pack" could have been forced to die by attempting
allocate an unreasonably large amount of memory with a crafted push
certificate; this has been fixed.

* bc/push-cert-receive-fix:
  builtin/receive-pack: fix incorrect pointer arithmetic

Removing an entry from a notes tree and then looking another note
entry from the resulting tree using the internal notes API
functions did not work as expected.  No in-tree users of the API
has such access pattern, but it still is worth fixing.

* mh/notes-tree-consolidate-fix:
  notes: do not break note_tree structure in note_tree_consolidate()

A recent update to "rebase -i" stopped running hooks for the "git
commit" command during "reword" action, which has been fixed.

* js/rebase-i-reword-to-run-hooks:
  sequencer: allow the commit-msg hooks to run during a `reword`
  sequencer: make commit options more extensible
  t7504: document regression: reword no longer calls commit-msg