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

The command-line completion script (in contrib/) has been updated.

* tb/complete-rebase-i-edit-todo:
  completion: offer '--edit-todo' during interactive rebase

git_path() and mkpath() are handy helper functions but it is easy
to misuse, as the callers need to be careful to keep the number of
active results below 4.  Their uses have been reduced.

* jk/git-path:
  memoize common git-path "constant" files
  get_repo_path: refactor path-allocation
  find_hook: keep our own static buffer
  refs.c: remove_empty_directories can take a strbuf
  refs.c: avoid git_path assignment in lock_ref_sha1_basic
  refs.c: avoid repeated git_path calls in rename_tmp_log
  refs.c: simplify strbufs in reflog setup and writing
  path.c: drop git_path_submodule
  refs.c: remove extra git_path calls from read_loose_refs
  remote.c: drop extraneous local variable from migrate_file
  prefer mkpathdup to mkpath in assignments
  prefer git_pathdup to git_path in some possibly-dangerous cases
  add_to_alternates_file: don't add duplicate entries
  t5700: modernize style
  cache.h: complete set of git_path_submodule helpers
  cache.h: clarify documentation for git_path, et al

Long overdue micro clean-up.

* jc/finalize-temp-file:
  sha1_file.c: rename move_temp_to_file() to finalize_object_file()

"git clone $URL", when cloning from a site whose sole purpose is to
host a single repository (hence, no path after <scheme>://<site>/),
tried to use the site name as the new repository name, but did not
remove username or password when <site> part was of the form
<user>@<pass>:<host>.  The code is taught to redact these.

* ps/guess-repo-name-at-root:
  clone: abort if no dir name could be guessed
  clone: do not use port number as dir name
  clone: do not include authentication data in guessed dir

"git clone $URL" in recent releases of Git contains a regression in
the code that invents a new repository name incorrectly based on
the $URL.  This has been corrected.

* jk/guess-repo-name-regression-fix:
  clone: use computed length in guess_dir_name
  clone: add tests for output directory

A negative !ref entry in multi-value transfer.hideRefs
configuration can be used to say "don't hide this one".

* jk/negative-hiderefs:
  refs: support negative transfer.hideRefs
  docs/config.txt: reorder hideRefs config

Running tests with the "-x" option to make them verbose had some
unpleasant interactions with other features of the test suite.

* jk/test-with-x:
  test-lib: disable trace when test is not verbose
  test-lib: turn off "-x" tracing during chain-lint check

t1509 test that requires a dedicated VM environment had some
bitrot, which has been corrected.

* ps/t1509-chroot-test-fixup:
  tests: fix cleanup after tests in t1509-root-worktree
  tests: fix broken && chains in t1509-root-worktree

* sb/check-return-from-read-ref:
  transport-helper: die on errors reading refs.

"git pull" in recent releases of Git has a regression in the code
that allows custom path to the --upload-pack=<program>.  This has
been corrected.

Note that this is irrelevant for 'master' with "git pull" rewritten
in C.

* mm/pull-upload-pack:
  pull.sh: quote $upload_pack when passing it to git-fetch

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

Allow untracked cache (experimental) to be used when sparse
checkout (experimental) is also in use.

* dt/untracked-sparse:
  untracked-cache: support sparse checkout

* ta/docfix-index-format-tech:
  typofix for index-format.txt

An off-by-one error made "git remote" to mishandle a remote with a
single letter nickname.

* mh/get-remote-group-fix:
  get_remote_group(): use skip_prefix()
  get_remote_group(): eliminate superfluous call to strcspn()
  get_remote_group(): rename local variable "space" to "wordlen"
  get_remote_group(): handle remotes with single-character names

"git pull --rebase" has been taught to pay attention to
rebase.autostash configuration.

* kd/pull-rebase-autostash:
  pull: allow dirty tree when rebase.autostash enabled

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

* sb/remove-unused-var-from-builtin-add:
  add: remove dead code

* sb/parse-options-codeformat:
  parse-options: align curly braces for all options

The code to perform multi-tree merges has been taught to repopulate
the cache-tree upon a successful merge into the index, so that
subsequent "diff-index --cached" (hence "status") and "write-tree"
(hence "commit") will go faster.

The same logic in "git checkout" may now be removed, but that is a
separate issue.

* dt/unpack-trees-cache-tree-revalidate:
  unpack-trees: populate cache-tree on successful merge

Tests that assume how reflogs are represented on the filesystem too
much have been corrected.

* dt/reflog-tests:
  tests: remove some direct access to .git/logs
  t/t7509: remove unnecessary manipulation of reflog

The "new-worktree-mode" hack in "checkout" that was added in
nd/multiple-work-trees topic has been removed by updating the
implementation of new "worktree add".

* es/worktree-add-cleanup: (25 commits)
  Documentation/git-worktree: fix duplicated 'from'
  Documentation/config: mention "now" and "never" for 'expire' settings
  Documentation/git-worktree: fix broken 'linkgit' invocation
  checkout: drop intimate knowledge of newly created worktree
  worktree: populate via "git reset --hard" rather than "git checkout"
  worktree: avoid resolving HEAD unnecessarily
  worktree: make setup of new HEAD distinct from worktree population
  worktree: detect branch-name/detached and error conditions locally
  worktree: add_worktree: construct worktree-population command locally
  worktree: elucidate environment variables intended for child processes
  worktree: make branch creation distinct from worktree population
  worktree: add: suppress auto-vivication with --detach and no <branch>
  worktree: make --detach mutually exclusive with -b/-B
  worktree: introduce options container
  worktree: simplify new branch (-b/-B) option checking
  worktree: improve worktree setup message
  branch: publish die_if_checked_out()
  checkout: teach check_linked_checkout() about symbolic link HEAD
  checkout: check_linked_checkout: simplify symref parsing
  checkout: check_linked_checkout: improve "already checked out" aesthetic
  ...

Rewrite "am" in "C".

* pt/am-builtin: (46 commits)
  git-am: add am.threeWay config variable
  builtin-am: remove redirection to git-am.sh
  builtin-am: check for valid committer ident
  builtin-am: implement legacy -b/--binary option
  builtin-am: implement -i/--interactive
  builtin-am: support and auto-detect mercurial patches
  builtin-am: support and auto-detect StGit series files
  builtin-am: support and auto-detect StGit patches
  builtin-am: rerere support
  builtin-am: invoke post-applypatch hook
  builtin-am: invoke pre-applypatch hook
  builtin-am: invoke applypatch-msg hook
  builtin-am: support automatic notes copying
  builtin-am: invoke post-rewrite hook
  builtin-am: implement -S/--gpg-sign, commit.gpgsign
  builtin-am: implement --committer-date-is-author-date
  builtin-am: implement --ignore-date
  builtin-am: pass git-apply's options to git-apply
  builtin-am: implement --[no-]scissors
  builtin-am: support --keep-cr, am.keepcr
  ...

Remove remaining cruft from  "git checkout --to", which
transitioned to "git worktree add".

* es/worktree-add:
  config: rename "gc.pruneWorktreesExpire" to "gc.worktreePruneExpire"
  Documentation/git-worktree: wordsmith worktree-related manpages
  Documentation/config: fix stale "git prune --worktree" reference
  Documentation/git-worktree: fix incorrect reference to file "locked"
  Documentation/git-worktree: consistently use term "linked working tree"

Code and documentation clean-up to "git bisect".

* ad/bisect-cleanup:
  bisect: don't mix option parsing and non-trivial code
  bisect: simplify the addition of new bisect terms
  bisect: replace hardcoded "bad|good" by variables
  Documentation/bisect: revise overall content
  Documentation/bisect: move getting help section to the end
  bisect: correction of typo

One of the most common uses of git_path() is to pass a
constant, like git_path("MERGE_MSG"). This has two
drawbacks:

  1. The return value is a static buffer, and the lifetime
     is dependent on other calls to git_path, etc.

  2. There's no compile-time checking of the pathname. This
     is OK for a one-off (after all, we have to spell it
     correctly at least once), but many of these constant
     strings appear throughout the code.

This patch introduces a series of functions to "memoize"
these strings, which are essentially globals for the
lifetime of the program. We compute the value once, take
ownership of the buffer, and return the cached value for
subsequent calls.  cache.h provides a helper macro for
defining these functions as one-liners, and defines a few
common ones for global use.

Using a macro is a little bit gross, but it does nicely
document the purpose of the functions. If we need to touch
them all later (e.g., because we learned how to change the
git_dir variable at runtime, and need to invalidate all of
the stored values), it will be much easier to have the
complete list.

Note that the shared-global functions have separate, manual
declarations. We could do something clever with the macros
(e.g., expand it to a declaration in some places, and a
declaration _and_ a definition in path.c). But there aren't
that many, and it's probably better to stay away from
too-magical macros.

Likewise, if we abandon the C preprocessor in favor of
generating these with a script, we could get much fancier.
E.g., normalizing "FOO/BAR-BAZ" into "git_path_foo_bar_baz".
But the small amount of saved typing is probably not worth
the resulting confusion to readers who want to grep for the
function's definition.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The get_repo_path function calls mkpath() and then does some
non-trivial operations on it, like calling
is_git_directory() and read_gitfile(). These are actually
OK (they do not use more pathname static buffers
themselves), but it takes a fair bit of work to verify.

Let's use our own strbuf to store the path, and we can
simply reuse it for each iteration of the loop (we can even
avoid rewriting the beginning part, since we are trying a
series of suffixes).

To make the strbuf cleanup easier, we split out a thin
wrapper. As a bonus, this wrapper can factor out the
canonicalization that happens in all of the early-return
code paths.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The find_hook function returns the results of git_path,
which is a static buffer shared by other path-related calls.
Returning such a buffer is slightly dangerous, because it
can be overwritten by seemingly unrelated functions.

Let's at least keep our _own_ static buffer, so you can
only get in trouble by calling find_hook in quick
succession, which is less likely to happen and more obvious
to notice.

While we're at it, let's add some documentation of the
function's limitations.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The first thing we do in this function is copy the input
into a strbuf. Of the 4 callers, 3 of them already have a
strbuf we could use. Let's just take the strbuf, and convert
the remaining caller to use a strbuf, rather than a raw
git_path. This is safer, anyway, as remove_dir_recursively
is a non-trivial function that might use the pathname
buffers itself (this is _probably_ OK, as the likely culprit
would be calling resolve_gitlink_ref, but we do not pass the
proper flags to ask it to avoid blowing away gitlinks).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Assigning the result of git_path is a bad pattern, because
it's not immediately obvious how long you expect the content
to stay valid (and it may be overwritten by subsequent
calls). Let's use a function-local strbuf here instead,
which we know is safe (we just have to remember to free it
in all code paths).

As a bonus, we get rid of a confusing variable-reuse
("ref_file" is used for two distinct purposes).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Because it's not safe to store the static-buffer results of
git_path for a long time, we end up formatting the same
filename over and over. We can fix this by using a
function-local strbuf to store the formatted pathname and
avoid repeating ourselves.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Commit 1a83c240 (git_snpath(): retire and replace with
strbuf_git_path(), 2014-11-30) taught log_ref_setup and
log_ref_write_1 to take a strbuf parameter, rather than a
bare string. It then makes an alias to the strbuf's "buf"
field under the original name.

This made the original diff much shorter, but the resulting
code is more complicated that it needs to be. Since we've
aliased the pointer, we drop our reference to the strbuf to
ensure we don't accidentally change it. But if we simply
drop our alias and use "logfile.buf" directly, we do not
have to worry about this aliasing. It's a larger diff, but
the resulting code is simpler.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

There are no callers of the slightly-dangerous static-buffer
git_path_submodule left. Let's drop it.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In iterating over the loose refs in "refs/foo/", we keep a
running strbuf with "refs/foo/one", "refs/foo/two", etc. But
we also need to access these files in the filesystem, as
".git/refs/foo/one", etc. For this latter purpose, we make a
series of independent calls to git_path(). These are safe
(we only use the result to call stat()), but assigning the
result of git_path is a suspicious pattern that we'd rather
avoid.

This patch keeps a running buffer with ".git/refs/foo/", and
we can just append/reset each directory element as we loop.
This matches how we handle the refnames. It should also be
more efficient, as we do not keep formatting the same
".git/refs/foo" prefix (which can be arbitrarily deep).

Technically we are dropping a call to strbuf_cleanup() on
each generated filename, but that's OK; it wasn't doing
anything, as we are putting in single-level names we read
from the filesystem (so it could not possibly be cleaning up
cruft like "./" in this instance).

A clever reader may also note that the running refname
buffer ("refs/foo/") is actually a subset of the filesystem
path buffer (".git/refs/foo/"). We could get by with one
buffer, indexing the length of $GIT_DIR when we want the
refname. However, having tried this, the resulting code
actually ends up a little more confusing, and the efficiency
improvement is tiny (and almost certainly dwarfed by the
system calls we are making).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It's an anti-pattern to assign the result of git_path to a
variable, since other calls may reuse our buffer. In this
case, we feed the result to unlink_or_warn immediately
afterwards, so it's OK. However, it's nice to avoid
assignment entirely, which makes it more obvious that
there's no bug.

We can just pass the result directly to unlink_or_warn,
which is a known-simple function. As a bonus, the code flow
is a little more obvious, as we eliminate an extra
conditional (a reader does not have to wonder any more
"under which circumstances is 'path' set?").
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

As with the previous commit to git_path, assigning the
result of mkpath is suspicious, since it is not clear
whether we will still depend on the value after it may have
been overwritten by subsequent calls. This patch converts
low-hanging fruit to use mkpathdup instead of mkpath (with
the downside that we must remember to free the result).
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Because git_path uses a static buffer that is shared with
calls to git_path, mkpath, etc, it can be dangerous to
assign the result to a variable or pass it to a non-trivial
function. The value may change unexpectedly due to other
calls.

None of the cases changed here has a known bug, but they're
worth converting away from git_path because:

  1. It's easy to use git_pathdup in these cases.

  2. They use constructs (like assignment) that make it
     hard to tell whether they're safe or not.

The extra malloc overhead should be trivial, as an
allocation should be an order of magnitude cheaper than a
system call (which we are clearly about to make, since we
are constructing a filename). The real cost is that we must
remember to free the result.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The add_to_alternates_file function blindly uses
hold_lock_file_for_append to copy the existing contents, and
then adds the new line to it. This has two minor problems:

  1. We might add duplicate entries, which are ugly and
     inefficient.

  2. We do not check that the file ends with a newline, in
     which case we would bogusly append to the final line.
     This is quite unlikely in practice, though, as we call
     this function only from git-clone, so presumably we are
     the only writers of the file (and we always add a
     newline).

Instead of using hold_lock_file_for_append, let's copy the
file line by line, which ensures all records are properly
terminated. If we see an extra line, we can simply abort the
update (there is no point in even copying the rest, as we
know that it would be identical to the original).

As a bonus, we also get rid of some calls to the
static-buffer mkpath and git_path functions.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The early part of this test is rather old, and does not
follow our usual style guidelines. In particular:

  - the tests liberally chdir, and expect out-of-test "cd"
    commands to return them to a sane state

  - test commands aren't indented at all

  - there are a lot of minor formatting nits, like the
    opening quote of the test block on the wrong line,
    spaces after ">", etc

This patch fixes the style issues, and uses a few helper
functions, along with subshells and "git -C", to avoid
changing the cwd of the main script.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The git_path function has "git_pathdup" and
"strbuf_git_path" variants, but git_submodule_path only
comes in the dangerous, static-buffer variant. That makes
refactoring callers to use the safer functions hard (since
they don't exist).

Since we're already using a strbuf behind the scenes, it's
easy to expose all three of these interfaces with thin
wrappers.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>