git p4 test: make sure P4CONFIG relative path works

This adds a test for the fix in bf1d68f (git-p4: use absolute
directory for PWD env var, 2011-12-09).  It is necessary to
set PWD to an absolute path so that p4 can find files referenced
by non-absolute paths, like the value of the P4CONFIG environment
variable.

P4 does not open files directly; it builds a path by prepending
the contents of the PWD environment variable.

Signed-off-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git p4 test: should honor symlink in p4 client root

This test fails when the p4 client root includes
a symlink.  It complains:

    Path /vol/bar/projects/foo/... is not under client root /p/foo

and dumps a traceback.

Signed-off-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git p4: avoid expanding client paths in chdir

The generic chdir() helper sets the PWD environment
variable, as that is what is used by p4 to know its
current working directory.  Normally the shell would
do this, but in git-p4, we must do it by hand.

However, when the path contains a symbolic link,
os.getcwd() will return the physical location.  If the
p4 client specification includes symlinks, setting PWD
to the physical location causes p4 to think it is not
inside the client workspace.  It complains, e.g.

    Path /vol/bar/projects/foo/... is not under client root /p/foo

One workaround is to use AltRoots in the p4 client specification,
but it is cleaner to handle it directly in git-p4.

Other uses of chdir still require setting PWD to an
absolute path so p4 features like P4CONFIG work.  See
bf1d68f (git-p4: use absolute directory for PWD env
var, 2011-12-09).

[ pw: tweak patch and commit message ]

Thanks-to: John Keeping <john@keeping.me.uk>
Signed-off-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
cache.h: drop LOCAL_REPO_ENV_SIZE

We keep a static array of variables that should be cleared
when invoking a sub-process on another repo. We statically
size the array with the LOCAL_REPO_ENV_SIZE macro so that
any readers do not have to count it themselves.

As it turns out, no readers actually use the macro, and it
creates a maintenance headache, as modifications to the
array need to happen in two places (one to add the new
element, and another to bump the size).

Since it's NULL-terminated, we can just drop the size macro
entirely. While we're at it, we'll clean up some comments
around it, and add a new mention of it at the top of the
list of environment variable macros. Even though
local_repo_env is right below that list, it's easy to miss,
and additions to that list should consider local_repo_env.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation/git-push: clarify the description of defaults

We describe what gets pushed by default when the command line does
not give any <refspec> under the bullet point of <refspec>.

It is a bit unfriendly to expect users to read on <refspec> when
they are not giving any in the first place.  "What gets pushed" is
determined by taking many factors (<refspec> argument being only one
of them) into account, and is a property of the entire command, not
an individual argument.  Also we do not describe "Where the push
goes" when the command line does not say.

Give the description on "what gets pushed to where" upfront before
explaining individual arguments and options.

Also update the description of <refspec> to say what it is, what it
is used for, before explaining what shape it takes.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
for_each_reflog_ent(): extract a helper to process a single entry

Split the logic that takes a single line of reflog entry in a
strbuf, parses the message, and calls the callback function out of
the loop into a separate helper function.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
for_each_recent_reflog_ent(): simplify opening of a reflog file

There is no reason to use a temporary variable logfile.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
reflog: add for_each_reflog_ent_reverse() API

"git checkout -" is a short-hand for "git checkout @{-1}" and the
"@{nth}" notation for a negative number is to find nth previous
checkout in the reflog of the HEAD to determine the name of the
branch the user was on.  We would want to find the nth most recent
reflog entry that matches "checkout: moving from X to Y" for this.

Unfortunately, reflog is implemented as an append-only file, and the
API to iterate over its entries, for_each_reflog_ent(), reads the
file in order, giving the entries from the oldest to newer.  For the
purpose of finding nth most recent one, this API forces us to record
the last n entries in a rotating buffer and give the result out only
after we read everything.  To optimize for a common case of finding
the nth most recent one for a small value of n, we also have a side
API for_each_recent_reflog_ent() that starts reading near the end of
the file, but it still has to read the entries in the "wrong" order.
The implementation of understanding @{-1} uses this interface.

This all becomes unnecessary if we add an API to let us iterate over
reflog entries in the reverse order, from the newest to older.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
environment: add GIT_PREFIX to local_repo_env

The GIT_PREFIX variable is set based on our location within
the working tree. It should therefore be cleared whenever
GIT_WORK_TREE is cleared.

In practice, this doesn't cause any bugs, because none of
the sub-programs we invoke with local_repo_env cleared
actually care about GIT_PREFIX. But this is the right thing
to do, and future proofs us against that assumption changing.

While we're at it, let's define a GIT_PREFIX_ENVIRONMENT
macro; this avoids repetition of the string literal, which
can help catch any spelling mistakes in the code.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
setup: suppress implicit "." work-tree for bare repos

If an explicit GIT_DIR is given without a working tree, we
implicitly assume that the current working directory should
be used as the working tree. E.g.,:

  GIT_DIR=/some/repo.git git status

would compare against the cwd.

Unfortunately, we fool this rule for sub-invocations of git
by setting GIT_DIR internally ourselves. For example:

  git init foo
  cd foo/.git
  git status ;# fails, as we expect
  git config alias.st status
  git status ;# does not fail, but should

What happens is that we run setup_git_directory when doing
alias lookup (since we need to see the config), set GIT_DIR
as a result, and then leave GIT_WORK_TREE blank (because we
do not have one). Then when we actually run the status
command, we do setup_git_directory again, which sees our
explicit GIT_DIR and uses the cwd as an implicit worktree.

It's tempting to argue that we should be suppressing that
second invocation of setup_git_directory, as it could use
the values we already found in memory. However, the problem
still exists for sub-processes (e.g., if "git status" were
an external command).

You can see another example with the "--bare" option, which
sets GIT_DIR explicitly. For example:

  git init foo
  cd foo/.git
  git status ;# fails
  git --bare status ;# does NOT fail

We need some way of telling sub-processes "even though
GIT_DIR is set, do not use cwd as an implicit working tree".
We could do it by putting a special token into
GIT_WORK_TREE, but the obvious choice (an empty string) has
some portability problems.

Instead, we add a new boolean variable, GIT_IMPLICIT_WORK_TREE,
which suppresses the use of cwd as a working tree when
GIT_DIR is set. We trigger the new variable when we know we
are in a bare setting.

The variable is left intentionally undocumented, as this is
an internal detail (for now, anyway). If somebody comes up
with a good alternate use for it, and once we are confident
we have shaken any bugs out of it, we can consider promoting
it further.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'nd/count-garbage' into jch

Will cook in 'next'.

* nd/count-garbage:
  count-objects: report how much disk space taken by garbage files
  count-objects: report garbage files in pack directory too
  sha1_file: reorder code in prepare_packed_git_one()
  git-count-objects.txt: describe each line in -v output
Merge branch 'jc/fetch-raw-sha1' into jch

Allows requests to fetch objects at any tip of refs (including
hidden ones).  It seems that there may be use cases even outside
Gerrit (e.g. $gmane/215701).

Will cook in 'next'.

* jc/fetch-raw-sha1:
  fetch: fetch objects by their exact SHA-1 object names
  upload-pack: optionally allow fetching from the tips of hidden refs
  fetch: use struct ref to represent refs to be fetched
  parse_fetch_refspec(): clarify the codeflow a bit

Conflicts:
	cache.h
Merge branch 'jc/remove-treesame-parent-in-simplify-merges' into jch

The --simplify-merges logic did not cull irrelevant parents from a
merge that is otherwise not interesting with respect to the paths
we are following.

This touches a fairly core part of the revision traversal
infrastructure; even though I think this change is correct, please
report immediately if you find any unintended side effect.

Will cook in 'next'.

* jc/remove-treesame-parent-in-simplify-merges:
  simplify-merges: drop merge from irrelevant side branch

Conflicts:
	revision.c
Merge branch 'jc/remove-export-from-config-mak-in' into jch

config.mak.in template had an "export" line to cause a few
common makefile variables to be exported; if they need to be
expoted for autoconf/configure users, they should also be exported
for people who write config.mak the same way.  Move the "export" to
the main Makefile.  Also, stop exporting mandir that used to be
exported (only) when config.mak.autogen was used.  It would have
broken installation of manpages (but not other documentation
formats).

Will cook in 'next'.

* jc/remove-export-from-config-mak-in:
  Fix `make install` when configured with autoconf
  Makefile: do not export mandir/htmldir/infodir
  config.mak.in: remove unused definitions

Conflicts:
	config.mak.in
Merge branch 'nd/read-directory-recursive-optim' into jch

"git status" has been optimized by taking advantage of the fact
that paths that are already known to the index do not have to be
checked against the .gitignore mechanism under some conditions.

Will cook in 'next'.

* nd/read-directory-recursive-optim:
  read_directory: avoid invoking exclude machinery on tracked files
Merge branch 'jc/push-2.0-default-to-simple' into jch

Will cook in 'next' until Git 2.0.

* jc/push-2.0-default-to-simple:
  t5570: do not assume the "matching" push is the default
  t5551: do not assume the "matching" push is the default
  t5550: do not assume the "matching" push is the default
  doc: push.default is no longer "matching"
  push: switch default from "matching" to "simple"
  t9401: do not assume the "matching" push is the default
  t9400: do not assume the "matching" push is the default
  t7406: do not assume the "matching" push is the default
  t5531: do not assume the "matching" push is the default
  t5519: do not assume the "matching" push is the default
  t5517: do not assume the "matching" push is the default
  t5516: do not assume the "matching" push is the default
  t5505: do not assume the "matching" push is the default
  t5404: do not assume the "matching" push is the default

Conflicts:
	Documentation/config.txt
	builtin/push.c
Merge branch 'bc/commit-complete-lines-given-via-m-option' into jch

'git commit -m "$str"' when $str was already terminated with a LF
now avoids adding an extra LF to the message.

Will cook in 'next'.

* bc/commit-complete-lines-given-via-m-option:
  Documentation/git-commit.txt: rework the --cleanup section
  git-commit: only append a newline to -m mesg if necessary
  t7502: demonstrate breakage with a commit message with trailing newlines
  t/t7502: compare entire commit message with what was expected
Merge branch 'ob/imap-send-ssl-verify' into jch

Correctly connect to SSL/TLS sites that serve multiple hostnames on
a single IP by including Server Name Indication in the client-hello.

Will cook in 'next'.

* ob/imap-send-ssl-verify:
  imap-send: support Server Name Indication (RFC4366)
Merge branch 'jk/pkt-line-cleanup' into jch

Cleans up pkt-line API, implementation and its callers to make
them more robust.

Will cook in 'next'.

* jk/pkt-line-cleanup:
  remote-curl: always parse incoming refs
  remote-curl: move ref-parsing code up in file
  remote-curl: pass buffer straight to get_remote_heads
  teach get_remote_heads to read from a memory buffer
  pkt-line: share buffer/descriptor reading implementation
  pkt-line: provide a LARGE_PACKET_MAX static buffer
  pkt-line: move LARGE_PACKET_MAX definition from sideband
  pkt-line: teach packet_read_line to chomp newlines
  pkt-line: provide a generic reading function with options
  pkt-line: drop safe_write function
  pkt-line: move a misplaced comment
  write_or_die: raise SIGPIPE when we get EPIPE
  upload-archive: use argv_array to store client arguments
  upload-archive: do not copy repo name
  send-pack: prefer prefixcmp over memcmp in receive_status
  fetch-pack: fix out-of-bounds buffer offset in get_ack
  upload-pack: remove packet debugging harness
  upload-pack: do not add duplicate objects to shallow list
  upload-pack: use get_sha1_hex to parse "shallow" lines

Conflicts:
	builtin/fetch-pack.c
Merge branch 'da/difftool-fixes' into jch

Minor maintenance updates to difftool, and updates to its tests.

Will cook in 'next'.

* da/difftool-fixes:
  t7800: "defaults" is no longer a builtin tool name
  t7800: modernize tests
  t7800: update copyright notice
  difftool: silence uninitialized variable warning