z/OS port

* dm/port2zos:
  compat/bswap.h: detect endianness from XL C compiler macros
  Makefile: reorder linker flags in the git executable rule
  git-compat-util.h: support variadic macros with the XL C compiler

* oc/mergetools-beyondcompare:
  mergetool: rename bc3 to bc

Tighten the logic to decide that an unreachable cruft is
sufficiently old by covering corner cases such as an ancient object
becoming reachable and then going unreachable again, in which case
its retention period should be prolonged.

* jk/prune-mtime: (28 commits)
  drop add_object_array_with_mode
  revision: remove definition of unused 'add_object' function
  pack-objects: double-check options before discarding objects
  repack: pack objects mentioned by the index
  pack-objects: use argv_array
  reachable: use revision machinery's --indexed-objects code
  rev-list: add --indexed-objects option
  rev-list: document --reflog option
  t5516: test pushing a tag of an otherwise unreferenced blob
  traverse_commit_list: support pending blobs/trees with paths
  make add_object_array_with_context interface more sane
  write_sha1_file: freshen existing objects
  pack-objects: match prune logic for discarding objects
  pack-objects: refactor unpack-unreachable expiration check
  prune: keep objects reachable from recent objects
  sha1_file: add for_each iterators for loose and packed objects
  count-objects: use for_each_loose_file_in_objdir
  count-objects: do not use xsize_t when counting object size
  prune-packed: use for_each_loose_file_in_objdir
  reachable: mark index blobs as SEEN
  ...

Add machinery to alternatively use AsciiDoctor to format our
documentation.

* bc/asciidoctor:
  Documentation: remove Asciidoctor linkgit macro
  Documentation: refactor common operations into variables
  Documentation: implement linkgit macro for Asciidoctor
  Documentation: move some AsciiDoc parameters into variables

Asciidoctor provides an extension implementing a backend-independent
macro for dealing with manpage links just like the linkgit macro.  As
this is more likely to be up-to-date with future changes in Asciidoctor,
prefer using it over reimplementing in Git.

This reverts commit 773ee47c.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The Makefile performs several very similar tasks to convert AsciiDoc
files into either HTML or DocBook.  Move these items into variables to
reduce the duplication.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

There is no /usr/include/endian.h equivalent on z/OS, but the
compiler will define macros to indicate endianness on host and
target hardware.  This adds a test for these macros as a last
resort for determining byte order.
Signed-off-by: NDavid Michael <fedora.dm0@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The XL C compiler can fail due to mixing library path and object
file arguments, for example when linking git while building with
"gmake LDFLAGS=-L$prefix/lib".

Move the ALL_LDFLAGS variable expansion in the git executable rule
to be consistent with all the other linking rules, namely to have
LDFLAGS such as -L$where before the object files *.o being linked
together.
Signed-off-by: NDavid Michael <fedora.dm0@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When the XL C compiler is run with an appropriate language level or
suboption, it defines a feature test macro to indicate support for
variadic macros by defining __C99_MACRO_WITH_VA_ARGS C preprocessor
macro.

This was tested on z/OS, but it should also work on AIX according
to IBM documentation.
Signed-off-by: NDavid Michael <fedora.dm0@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

* jc/push-cert:
  push: heed user.signingkey for signed pushes

Code clean-up.

* sb/plug-transport-leak:
  .mailmap: add Stefan Bellers corporate mail address
  transport: free leaking head in transport_print_push_status()

Code clean-up.

* nd/dir-prep-exclude-cleanup:
  dir.c: remove the second declaration of "stk" in prep_exclude()

Allow us build with NO_PTHREADS=NoThanks compilation option.

* eb/no-pthreads:
  Handle atexit list internaly for unthreaded builds
  pack-objects: set number of threads before checking and warning
  index-pack: fix compilation with NO_PTHREADS

* wk/t1304-wo-USER:
  t1304: Set LOGNAME even if USER is unset or null

Doc update.

* tb/core-filemode-doc:
  core.filemode may need manual action

Add managed "env" array to child_process to clarify the lifetime
rules.

* rs/run-command-env-array:
  use env_array member of struct child_process
  run-command: add env_array, an optional argv_array for env

Update documentation mark-up.

* po/doc-status-markup:
  doc: fix 'git status --help' character quoting

Splitting pack-objects output into multiple packs is incompatible
with the use of reachability bitmap.

* jk/pack-objects-no-bitmap-when-splitting:
  pack-objects: turn off bitmaps when we split packs

push --signed promises to take user.signingkey as the signing key but
fails to read the config.

Make it do so.
Signed-off-by: NMichael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

Some internal error messages leaked out of the bash completion when
typing "git cmd <TAB>" and the machinery tried to complete
refnames.

* js/completion-hide-not-a-repo:
  completion: silence "fatal: Not a git repository" error

Newer versions of 'meld' breaks the auto-detection we use to see if
they are new enough to support the `--output` option.

* da/mergetool-meld:
  mergetools/meld: make usage of `--output` configurable and more robust

Allow a temporary directory specified to be used while running "git
mergetool" backend.

* da/mergetool-temporary-directory:
  t7610-mergetool: add test cases for mergetool.writeToTemp
  mergetool: add an option for writing to a temporary directory

Allow "git mergetool --help" to run outside a Git repository.

* da/mergetool-tool-help:
  difftool: don't assume that default sh is sane
  mergetool: don't require a work tree for --tool-help
  git-sh-setup: move GIT_DIR initialization into a function
  mergetool: use more conservative temporary filenames
  test-lib-functions: adjust style to match CodingGuidelines
  t7610-mergetool: prefer test_config over git config

Tweak the names of the three throw-away files "git mergetool" comes
up with to feed the merge tool backend, so that a file with a
single dot in its name in the original (e.g. "hello.c") will have
only one dot in these variants (e.g. "hello_BASE_4321.c").

* da/mergetool-temporary-filename:
  mergetool: use more conservative temporary filenames

The clean-up of this test script was long overdue and is a very
welcome change.

* da/mergetool-tests:
  test-lib-functions: adjust style to match CodingGuidelines
  t7610-mergetool: use test_config to isolate tests
  t7610-mergetool: add missing && and remove commented-out code
  t7610-mergetool: use tabs instead of a mix of tabs and spaces

The API to update refs have been restructured to allow introducing
a true transactional updates later.  We would even allow storing
refs in backends other than the traditional filesystem-based one.

* rs/ref-transaction: (25 commits)
  ref_transaction_commit: bail out on failure to remove a ref
  lockfile: remove unable_to_lock_error
  refs.c: do not permit err == NULL
  remote rm/prune: print a message when writing packed-refs fails
  for-each-ref: skip and warn about broken ref names
  refs.c: allow listing and deleting badly named refs
  test: put tests for handling of bad ref names in one place
  packed-ref cache: forbid dot-components in refnames
  branch -d: simplify by using RESOLVE_REF_READING
  branch -d: avoid repeated symref resolution
  reflog test: test interaction with detached HEAD
  refs.c: change resolve_ref_unsafe reading argument to be a flags field
  refs.c: make write_ref_sha1 static
  fetch.c: change s_update_ref to use a ref transaction
  refs.c: ref_transaction_commit: distinguish name conflicts from other errors
  refs.c: pass a list of names to skip to is_refname_available
  refs.c: call lock_ref_sha1_basic directly from commit
  refs.c: refuse to lock badly named refs in lock_ref_sha1_basic
  rename_ref: don't ask read_ref_full where the ref came from
  refs.c: pass the ref log message to _create/delete/update instead of _commit
  ...

Beyond Compare version 4 works the same way as version 3, so rename
the existing "bc3" adaptor to just "bc", while keeping "bc3" as a
backward compatible wrapper.
Noticed-by: NOlivier Croquette <ocroquette@free.fr>
Helped-by: NDavid Aguilar <davvid@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This "stk" shadows the first declaration at the top. There's currently
no bad effect. But let's avoid it.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Note that despite the private address being first and primary,
Google owns the copyright on this patch as any other patch I'll be
sending signed off by the sbeller@google.com address.
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Found by scan.coverity.com (ID: 1248110)
Signed-off-by: NStefan Beller <sbeller@google.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

A new filter to programatically edit the tail end of the commit log
messages.

* cc/interpret-trailers:
  Documentation: add documentation for 'git interpret-trailers'
  trailer: add tests for commands in config file
  trailer: execute command from 'trailer.<name>.command'
  trailer: add tests for "git interpret-trailers"
  trailer: add interpret-trailers command
  trailer: put all the processing together and print
  trailer: parse trailers from file or stdin
  trailer: process command line trailer arguments
  trailer: read and process config information
  trailer: process trailers from input message and arguments
  trailer: add data structures and basic functions

* rm/gitweb-start-form:
  gitweb: use start_form, not startform that was removed in CGI.pm 4.04

* ss/contrib-subtree-contacts:
  contacts: add a Makefile to generate docs and install
  subtree: add an install-html target

Code cleanup.

* jn/parse-config-slot:
  color_parse: do not mention variable name in error message
  pass config slots as pointers instead of offsets

* rs/receive-pack-argv-leak-fix:
  receive-pack: plug minor memory leak in unpack()

* ta/config-set:
  t1308: fix broken here document in test script

Test scripts were taught to notice "-x" option to show shell trace,
as if the tests were run under "sh -x".

* jk/test-shell-trace:
  test-lib.sh: support -x option for shell-tracing
  t5304: use helper to report failure of "test foo = bar"
  t5304: use test_path_is_* instead of "test -f"