This variable is only ever used by the routines in pager.c,
and other parts of the code should always use those routines
(like git_pager()) to make decisions about which pager to
use. Let's reduce its scope to prevent accidents.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In git_pager(), we really only care about getting the value
of core.pager. But to do so, we use the git_default_config()
callback, which loads many other values. Ordinarily it
isn't a big deal to load this config an extra time, as it
simply overwrites the values from the previous run. But it's
a bad idea here, for two reasons:

  1. The pager setup may be called very early in the
     program, before we have found the git repository. As a
     result, we may fail to read the correct repo-level
     config file.  This is a problem for core.pager, too,
     but we should at least try to minimize the pollution to
     other configured values.

  2. Because we call setup_pager() from git.c, basically
     every builtin command _may_ end up reading this config
     and getting an implicit git_default_config() setup.

     Which doesn't sound like a terrible thing, except that
     we don't do it consistently; it triggers only when
     stdout is a tty. So if a command forgets to load the
     default config itself (but depends on it anyway), it
     may appear to work, and then mysteriously fail when the
     pager is not in use.

We can improve this by loading _just_ the core.pager config
from git_pager().
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The comment at the top of pager.c claims that we've split
the code out so that Windows can do something different.
This dates back to f67b45f8 (Introduce trivial new pager.c
helper infrastructure, 2006-02-28), because the original
implementation used fork(). Later, we ended up sticking the
Windows #ifdefs into this file anyway. And then even later,
in ea27a18c (spawn pager via run_command interface,
2008-07-22) we unified the implementations.

So these days this comment is really saying nothing at all.
Let's drop it.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If we see an explicit "--no-index", we do not bother calling
setup_git_directory_gently() at all. This means that we may
miss out on reading repo-specific config.

It's arguable whether this is correct or not. If we were
designing from scratch, making "git diff --no-index"
completely ignore the repository makes some sense. But we
are nowhere near scratch, so let's look at the existing
behavior:

  1. If you're in the top-level of a repository and run an
     explicit "diff --no-index", the config subsystem falls
     back to reading ".git/config", and we will respect repo
     config.

  2. If you're in a subdirectory of a repository, then we
     still try to read ".git/config", but it generally
     doesn't exist. So "diff --no-index" there does not
     respect repo config.

  3. If you have $GIT_DIR set in the environment, we read
     and respect $GIT_DIR/config,

  4. If you run "git diff /tmp/foo /tmp/bar" to get an
     implicit no-index, we _do_ run the repository setup,
     and set $GIT_DIR (or respect an existing $GIT_DIR
     variable). We find the repo config no matter where we
     started, and respect it.

So we already respect the repository config in a number of
common cases, and case (2) is the only one that does not.
And at least one of our tests, t4034, depends on case (1)
behaving as it does now (though it is just incidental, not
an explicit test for this behavior).

So let's bring case (2) in line with the others by always
running the repository setup, even with an explicit
"--no-index". We shouldn't need to change anything else, as the
implicit case already handles the prefix.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If we see an explicit "git diff --no-index ../foo ../bar",
then we do not set up the git repository at all (we already
know we are in --no-index mode, so do not have to check "are
we in a repository?"), and hence have no "prefix" within the
repository. A patch generated by this command will have the
filenames "a/../foo" and "b/../bar", no matter which
directory we are in with respect to any repository.

However, in the implicit case, where we notice that the
files are outside the repository, we will have chdir()'d to
the top-level of the repository. We then feed the prefix
back to the diff machinery. As a result, running the same
diff from a subdirectory will result in paths that look like
"a/subdir/../../foo".

Besides being unnecessarily long, this may also be confusing
to the user: they don't care about the subdir or the
repository at all; it's just where they happened to be when
running the command. We should treat this the same as the
explicit --no-index case.

One way to address this would be to chdir() back to the
original path before running our diff. However, that's a bit
hacky, as we would also need to adjust $GIT_DIR, which could
be a relative path from our top-level.

Instead, we can reuse the diff machinery's RELATIVE_NAME
option, which automatically strips off the prefix. Note that
this _also_ restricts the diff to this relative prefix, but
that's OK for our purposes: we queue our own diff pairs
manually, and do not rely on that part of the diff code.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We can invoke no-index mode in two ways: by an explicit
request from the user, or implicitly by noticing that we
have two paths, and at least one is outside the repository.

If the user already told us --no-index, there is no need for
us to do the implicit test at all.  However, we currently
do, and downgrade our "explicit" to DIFF_NO_INDEX_IMPLICIT.

This doesn't have any user-visible behavior, though it's not
immediately obvious why. We only trigger the implicit check
when we have exactly two non-option arguments. And the only
code that cares about implicit versus explicit is an error
message that we show when we _don't_ have two non-option
arguments.

However, it's worth fixing anyway. Besides being slightly
more efficient, it makes the code easier to follow, which
will help when we modify it in future patches.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Patch-id does not require a repository because it is just
processing the incoming diff on stdin, but it may look at
git config for keys like patchid.stable.

Even though we do not setup_git_directory(), this works from
the top-level of a repository because we blindly look at
".git/config" in this case. But as the included test
demonstrates, it does not work from a subdirectory.

We can fix it by using RUN_SETUP_GENTLY. We do not take any
filenames from the user on the command line, so there's no
need to adjust them via prefix_filename().
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When "hash-object" is run without "-w", we don't need to be
in a git repository at all; we can just hash the object and
write its sha1 to stdout. However, if we _are_ in a git
repository, we would want to know that so we can follow the
normal rules for respecting config, .gitattributes, etc.

This happens to work at the top-level of a git repository
because we blindly read ".git/config", but as the included
test shows, it does not work when you are in a subdirectory.

The solution is to just do a "gentle" setup in this case. We
already take care to use prefix_filename() on any filename
arguments we get (to handle the "-w" case), so we don't need
to do anything extra to handle the side effects of repo
setup.

An alternative would be to specify RUN_SETUP_GENTLY for this
command in git.c, and then die if "-w" is set but we are not
in a repository. However, the error messages generated at
the time of setup_git_directory() are more detailed, so it's
better to find out which mode we are in, and then call the
appropriate function.
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>

The "are we talking with TTY, doing an interactive session?"
detection has been updated to work better for "Git for Windows".

* kb/msys2-tty:
  mingw: make isatty() recognize MSYS2's pseudo terminals (/dev/pty*)

"git difftool" learned to handle unmerged paths correctly in
dir-diff mode.

* da/difftool:
  difftool: handle unmerged files in dir-diff mode
  difftool: initialize variables for readability

A couple of bugs around core.autocrlf have been fixed.

* tb/core-eol-fix:
  convert.c: ident + core.autocrlf didn't work
  t0027: test cases for combined attributes
  convert: allow core.autocrlf=input and core.eol=crlf
  t0027: make commit_chk_wrnNNO() reliable

Many commands normalize command line arguments from NFD to NFC
variant of UTF-8 on OSX, but commands in the "diff" family did
not, causing "git diff $path" to complain that no such path is
known to Git.  They have been taught to do the normalization.

* ar/diff-args-osx-precompose:
  diff: run arguments through precompose_argv

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

Correct faulty recommendation to use "git submodule deinit ." when
de-initialising all submodules, which would result in a strange
error message in a pathological corner case.

* sb/submodule-deinit-all:
  submodule deinit: require '--all' instead of '.' for all submodules

"http.cookieFile" configuration variable clearly wants a pathname,
but we forgot to treat it as such by e.g. applying tilde expansion.

* bn/http-cookiefile-config:
  http: expand http.cookieFile as a path
  Documentation: config: improve word ordering for http.cookieFile

Running tests with '-x' option to trace the individual command
executions is a useful way to debug test scripts, but some tests
that capture the standard error stream and check what the command
said can be broken with the trace output mixed in.  When running
our tests under "bash", however, we can redirect the trace output
to another file descriptor to keep the standard error of programs
being tested intact.

* jk/test-send-sh-x-trace-elsewhere:
  test-lib: set BASH_XTRACEFD automatically

"git describe --contains" often made a hard-to-justify choice of
tag to give name to a given commit, because it tried to come up
with a name with smallest number of hops from a tag, causing an old
commit whose close descendant that is recently tagged were not
described with respect to an old tag but with a newer tag.  It did
not help that its computation of "hop" count was further tweaked to
penalize being on a side branch of a merge.  The logic has been
updated to favor using the tag with the oldest tagger date, which
is a lot easier to explain to the end users: "We describe a commit
in terms of the (chronologically) oldest tag that contains the
commit."

* js/name-rev-use-oldest-ref:
  name-rev: include taggerdate in considering the best name

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

Many 'linkgit:<git documentation page>' references were broken,
which are all fixed with this.

* jc/linkgit-fix:
  Documentation: fix linkgit references

CI test was taught to build documentation pages.

* ls/travis-build-doc:
  travis-ci: build documentation

"git fsck" learned to catch NUL byte in a commit object as
potential error and warn.

* jc/fsck-nul-in-commit:
  fsck: detect and warn a commit with embedded NUL
  fsck_commit_buffer(): do not special case the last validation

Portability enhancement for "rebase -i" to help platforms whose
shell does not like "for i in <empty>" (which is not POSIX-kosher).

* jk/rebase-interative-eval-fix:
  rebase--interactive: avoid empty list in shell for-loop

On Windows, .git and optionally any files whose name starts with a
dot are now marked as hidden, with a core.hideDotFiles knob to
customize this behaviour.

* js/windows-dotgit:
  mingw: remove unnecessary definition
  mingw: introduce the 'core.hideDotFiles' setting

Documentation for "git merge --verify-signatures" has been updated
to clarify that the signature of only the commit at the tip is
verified.  Also the phrasing used for signature and key validity is
adjusted to align with that used by OpenPGP.

* kf/gpg-sig-verification-doc:
  Documentation: clarify signature verification

Typofixes.

* lp/typofixes:
  typofix: assorted typofixes in comments, documentation and messages

Test fix.

* sb/z-is-gnutar-ism:
  t6041: do not compress backup tar file
  t3513: do not compress backup tar file

Mark several messages for translation.

* va/i18n-misc-updates:
  i18n: unpack-trees: avoid substituting only a verb in sentences
  i18n: builtin/pull.c: split strings marked for translation
  i18n: builtin/pull.c: mark placeholders for translation
  i18n: git-parse-remote.sh: mark strings for translation
  i18n: branch: move comment for translators
  i18n: branch: unmark string for translation
  i18n: builtin/rm.c: remove a comma ',' from string
  i18n: unpack-trees: mark strings for translation
  i18n: builtin/branch.c: mark option for translation
  i18n: index-pack: use plural string instead of normal one

Doc formatting fixes.

* bn/config-doc-tt-varnames:
  config: consistently format $variables in monospaced font
  config: describe 'pathname' value type

Message fix.

* nd/remote-plural-ours-plus-theirs:
  remote.c: specify correct plural form in "commit diverge" message

Test fix.

* ak/t4151-ls-files-could-be-empty:
  t4151: make sure argument to 'test -z' is given

Test fix.

* jc/test-seq:
  test-lib-functions.sh: rewrite test_seq without Perl
  test-lib-functions.sh: remove misleading comment on test_seq

Test fix.

* tb/t5601-sed-fix:
  t5601: Remove trailing space in sed expression

Message fix.

* va/i18n-remote-comment-to-align:
  i18n: remote: add comment for translators

Typofix.

* va/mailinfo-doc-typofix:
  Documentation/git-mailinfo: fix typo

* maint-2.7:
  archive-tar: convert snprintf to xsnprintf

MSYS2 emulates pseudo terminals via named pipes, and isatty() returns 0
for such file descriptors. Therefore, some interactive functionality
(such as launching a pager, asking if a failed unlink should be repeated
etc.) doesn't work when run in a terminal emulator that uses MSYS2's
ptys (such as mintty).

However, MSYS2 uses special names for its pty pipes ('msys-*-pty*'),
which allows us to distinguish them from normal piped input / output.

On startup, check if stdin / stdout / stderr are connected to such pipes
using the NtQueryObject API from NTDll.dll. If the names match, adjust
the flags in MSVCRT's ioinfo structure accordingly.
Signed-off-by: NKarsten Blees <blees@dcon.de>
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

* jk/war-on-sprintf:
  archive-tar: convert snprintf to xsnprintf

Commit f2f02675 (archive-tar: use xsnprintf for trivial
formatting, 2015-09-24) converted cases of "sprintf" to
"xsnprintf", but accidentally left one as just "snprintf".
This meant that we could silently truncate the resulting
buffer instead of flagging an error.

In practice, this is impossible to achieve, as we are
formatting a ustar checksum, which can be at most 7
characters. But the point of xsnprintf is to document and
check for "should be impossible" conditions; this site was
just accidentally mis-converted during f2f02675.
Noticed-by: NPaul Green <Paul.Green@stratus.com>
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>