Convert the declaration and definition of strbuf_add_unique_abbrev to
make it take a pointer to struct object_id.  Predeclare the struct in
strbuf.h, as cache.h includes strbuf.h before it declares the struct,
and otherwise the struct declaration would have the wrong scope.

Apply the following semantic patch, along with the standard object_id
transforms, to adjust the callers:

@@
expression E1, E2, E3;
@@
- strbuf_add_unique_abbrev(E1, E2.hash, E3);
+ strbuf_add_unique_abbrev(E1, &E2, E3);

@@
expression E1, E2, E3;
@@
- strbuf_add_unique_abbrev(E1, E2->hash, E3);
+ strbuf_add_unique_abbrev(E1, E2, E3);
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This is necessary in order to convert find_unique_abbrev.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert the callback functions for read_tree_recursive to take a pointer
to struct object_id.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert the sha1 member of this struct to be an array of struct
object_id instead.  This change is needed to convert find_unique_abbrev.

Convert some instances of hard-coded constants to use the_hash_algo as
well.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert the remaining portions of cache-tree.c to use struct object_id.
Convert several instances of 20 to use the_hash_algo instead.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert write_index_as_tree and write_cache_as_tree to use struct
object_id.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This is needed to convert parts of the cache-tree code.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Convert the index_bulk_checkin function, and the static functions it
calls, to use pointers to struct object_id.
Signed-off-by: Nbrian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

"git diff" and friends learned funcname patterns for Go language
source files.

* ag/userdiff-go-funcname:
  userdiff: add built-in pattern for golang

"git commit" used to run "gc --auto" near the end, which was lost
when the command was reimplemented in C by mistake.

* ab/gc-auto-in-commit:
  commit: run git gc --auto just before the post-commit hook

Writing out the index file when the only thing that changed in it
is the untracked cache information is often wasteful, and this has
been optimized out.

* bp/untracked-cache-noflush:
  untracked cache: use git_env_bool() not getenv() for customization
  dir.c: don't flag the index as dirty for changes to the untracked cache

Perf test regression fix.

* rs/perf-repeat-thrice-by-default:
  perf: use GIT_PERF_REPEAT_COUNT=3 by default even without config file

Docfix.

* mk/doc-pretty-fill:
  docs/pretty-formats: fix typo '% <(<N>)' -> '%<|(<N>)'

Test framework tweak to catch developer thinko.

* jc/test-must-be-empty:
  test_must_be_empty: make sure the file exists, not just empty

Micro optimization in revision traversal code.

* ds/mark-parents-uninteresting-optim:
  revision.c: reduce object database queries

While finding unique object name abbreviation, the code may
accidentally have read beyond the end of the array of object names
in a pack.

* ds/find-unique-abbrev-optim:
  sha1_name: fix uninitialized memory errors

"git subtree" script (in contrib/) scripted around "git log", whose
output got affected by end-user configuration like log.showsignature

* sg/subtree-signed-commits:
  subtree: fix add and pull for GPG-signed commits

Threaded "git grep" has been optimized to avoid allocation in code
section that is covered under a mutex.

* rv/grep-cleanup:
  grep: simplify grep_oid and grep_file
  grep: move grep_source_init outside critical section

Code cleanup.

* ot/ref-filter-cleanup:
  ref-filter: get rid of goto
  ref-filter: get rid of duplicate code

"git status" can spend a lot of cycles to compute the relation
between the current branch and its upstream, which can now be
disabled with "--no-ahead-behind" option.

* jh/status-no-ahead-behind:
  status: support --no-ahead-behind in long format
  status: update short status to respect --no-ahead-behind
  status: add --[no-]ahead-behind to status and commit for V2 format.
  stat_tracking_info: return +1 when branches not equal

Build the executable in 'script' phase in Travis CI integration, to
follow the established practice, rather than during 'before_script'
phase.  This allows the CI categorize the failures better ('failed'
is project's fault, 'errored' is build environment's).

* sg/travis-build-during-script-phase:
  travis-ci: build Git during the 'script' phase

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

Y2k20 fix ;-) for our perl scripts.

* bw/perl-timegm-timelocal-fix:
  perl: call timegm and timelocal with 4-digit year

Code clean-up.

* jk/strbuf-read-file-close-error:
  strbuf_read_file(): preserve errno across close() call

Avoid using identifiers that clash with C++ keywords.  Even though
it is not a goal to compile Git with C++ compilers, changes like
this help use of code analysis tools that targets C++ on our
codebase.

* bw/c-plus-plus: (37 commits)
  replace: rename 'new' variables
  trailer: rename 'template' variables
  tempfile: rename 'template' variables
  wrapper: rename 'template' variables
  environment: rename 'namespace' variables
  diff: rename 'template' variables
  environment: rename 'template' variables
  init-db: rename 'template' variables
  unpack-trees: rename 'new' variables
  trailer: rename 'new' variables
  submodule: rename 'new' variables
  split-index: rename 'new' variables
  remote: rename 'new' variables
  ref-filter: rename 'new' variables
  read-cache: rename 'new' variables
  line-log: rename 'new' variables
  imap-send: rename 'new' variables
  http: rename 'new' variables
  entry: rename 'new' variables
  diffcore-delta: rename 'new' variables
  ...

Code clean-up.

* rs/strbuf-read-file-or-whine:
  sequencer: factor out strbuf_read_file_or_whine()

Doc markup fix.

* ms/non-ascii-ticks:
  Documentation/gitsubmodules.txt: avoid non-ASCII apostrophes

Test framework update.

* jk/test-helper-v-output-fix:
  t: send verbose test-helper output to fd 4

Code clean-up.

* jk/cached-commit-buffer:
  revision: drop --show-all option
  commit: drop uses of get_cached_commit_buffer()

Doc update.

* bw/doc-submodule-recurse-config-with-clone:
  submodule: indicate that 'submodule.recurse' doesn't apply to clone

Since Git 1.7.9, "git merge" defaulted to --no-ff (i.e. even when
the side branch being merged is a descendant of the current commit,
create a merge commit instead of fast-forwarding) when merging a
tag object.  This was appropriate default for integrators who pull
signed tags from their downstream contributors, but caused an
unnecessary merges when used by downstream contributors who
habitually "catch up" their topic branches with tagged releases
from the upstream.  Update "git merge" to default to --no-ff only
when merging a tag object that does *not* sit at its usual place in
refs/tags/ hierarchy, and allow fast-forwarding otherwise, to
mitigate the problem.

* jc/allow-ff-merging-kept-tags:
  merge: allow fast-forward when merging a tracked tag

Hotfix for a topic already in 'master'.

* ab/simplify-perl-makefile:
  Makefile: generate Git(3pm) as dependency of the 'doc' and 'man' targets

"git add -p" used to offer "/" (look for a matching hunk) as a
choice, even there was only one hunk, which has been corrected.
Also the single-key help is now given only for keys that are
enabled (e.g. help for '/' won't be shown when there is only one
hunk).

* pw/add-p-single:
  add -p: improve error messages
  add -p: only bind search key if there's more than one hunk
  add -p: only display help for active keys

Test update.

* sg/t6300-modernize:
  t6300-for-each-ref: fix "more than one quoting style" tests

Devdoc update.

* sb/color-h-cleanup:
  color.h: document and modernize header

The new "--show-current-patch" option gives an end-user facing way
to get the diff being applied when "git rebase" (and "git am")
stops with a conflict.

* nd/rebase-show-current-patch:
  rebase: introduce and use pseudo-ref REBASE_HEAD
  rebase: add --show-current-patch
  am: add --show-current-patch

"git send-email" learned to complain when the batch-size option is
not defined when the relogin-delay option is, since these two are
mutually required.

* xz/send-email-batch-size:
  send-email: error out when relogin delay is missing

Clarify how configured fetch refspecs interact with the "--prune"
option of "git fetch", and also add a handy short-hand for getting
rid of stale tags that are locally held.

* ab/fetch-prune:
  fetch: make the --prune-tags work with <url>
  fetch: add a --prune-tags option and fetch.pruneTags config
  fetch tests: add scaffolding for the new fetch.pruneTags
  git-fetch & config doc: link to the new PRUNING section
  git remote doc: correct dangerous lies about what prune does
  git fetch doc: add a new section to explain the ins & outs of pruning
  fetch tests: fetch <url> <spec> as well as fetch [<remote>]
  fetch tests: expand case/esac for later change
  fetch tests: double quote a variable for interpolation
  fetch tests: test --prune and refspec interaction
  fetch tests: add a tag to be deleted to the pruning tests
  fetch tests: re-arrange arguments for future readability
  fetch tests: refactor in preparation for testing tag pruning
  remote: add a macro for "refs/tags/*:refs/tags/*"
  fetch: stop accessing "remote" variable indirectly
  fetch: trivially refactor assignment to ref_nr
  fetch: don't redundantly NULL something calloc() gave us

Code clean-up.

* sm/mv-dry-run-update:
  mv: remove unneeded 'if (!show_only)'
  t7001: add test case for --dry-run