Docfix.

* jh/config-unset-doc-fix:
  git-config.1: remove value from positional args in unset usage

Docfix.

* js/doc-platform-support-link-fix:
  docs: fix the `maintain-git` links in `technical/platform-support`

A new configuration variable remote.<name>.serverOption makes the
transport layer act as if the --serverOption=<value> option is
given from the command line.

* xx/remote-server-option-config:
  ls-remote: leakfix for not clearing server_options
  fetch: respect --server-option when fetching multiple remotes
  transport.c::handshake: make use of server options from remote
  remote: introduce remote.<name>.serverOption configuration
  transport: introduce parse_transport_option() method

On macOS, fsmonitor can fall into a race condition that results in
a client waiting forever to be notified for an event that have
already happened.  This problem has been corrected.

* jk/fsmonitor-event-listener-race-fix:
  fsmonitor: initialize fs event listener before accepting clients
  simple-ipc: split async server initialization and running

Docfix.

* kh/merge-tree-doc:
  doc: merge-tree: improve example script

Test modernization.

* aa/t7300-modernize:
  t7300-clean.sh: use test_path_* helper functions for error logging

Code clean-up.

* kn/loose-object-layer-wo-global-hash:
  loose: don't rely on repository global state

"git rebase --rebase-merges" now uses branch names as labels when
able.

* ng/rebase-merges-branch-name-as-label:
  rebase-merges: try and use branch names as labels
  rebase-update-refs: extract load_branch_decorations
  load_branch_decorations: fix memory leak with non-static filters

Doc updates.

* jc/doc-refspec-syntax:
  doc: clarify <src> in refspec syntax

"git maintenance start" crashed due to an uninitialized variable
reference, which has been corrected.

* ps/maintenance-start-crash-fix:
  builtin/gc: fix crash when running `git maintenance start`

Doc updates.

* kh/checkout-ignore-other-docfix:
  checkout: refer to other-worktree branch, not ref

Docfix.

* xx/protocol-v2-doc-markup-fix:
  Documentation/gitprotocol-v2.txt: fix a slight inconsistency in format

Leakfix.

* tc/bundle-uri-leakfix:
  bundle-uri: plug leak in unbundle_from_file()

Fail gracefully instead of crashing when attempting to write the
contents of a corrupt in-core index as a tree object.

* ps/cache-tree-w-broken-index-entry:
  unpack-trees: detect mismatching number of cache-tree/index entries
  cache-tree: detect mismatching number of index entries
  cache-tree: refactor verification to return error codes

An extra worktree attached to a repository points at each other to
allow finding the repository from the worktree and vice versa
possible.  Turn this linkage to relative paths.

* cw/worktree-relative:
  worktree: add test for path handling in linked worktrees
  worktree: link worktrees with relative paths
  worktree: refactor infer_backlink() to use *strbuf
  worktree: repair copied repository and linked worktrees

Signed-off-by: Taylor Blau <me@ttaylorr.com>

Doc update.

* bf/t-readme-mention-reftable:
  t/README: add missing value for GIT_TEST_DEFAULT_REF_FORMAT

Build fix.

* pb/clar-build-fix:
  Makefile: fix dependency for $(UNIT_TEST_DIR)/clar/clar.o

Typofixes.

* ak/typofixes:
  t: fix typos
  t/helper: fix a typo
  t/perf: fix typos
  t/unit-tests: fix typos
  contrib: fix typos
  compat: fix typos

A "git fetch" from the superproject going down to a submodule used
a wrong remote when the default remote names are set differently
between them.

* db/submodule-fetch-with-remote-name-fix:
  submodule: correct remote name with fetch

Teaches 'shortlog' to explicitly use SHA-1 when operating outside of
a repository.

* wm/shortlog-hash:
  builtin/shortlog: explicitly set hash algo when there is no repo

Fixes compile time warnings with 64-bit MSVC.

* sk/msvc-warnings:
  mingw.c: Fix complier warnings for a 64 bit msvc

More typofixes.

* ak/typofix:
  t: fix typos

Describe the policy to introduce breaking changes.

* jc/breaking-changes-early-adopter-option:
  BreakingChanges: early adopter option

Enable Windows-based CI in GitLab.

* ps/ci-gitlab-windows:
  gitlab-ci: exercise Git on Windows
  gitlab-ci: introduce stages and dependencies
  ci: handle Windows-based CI jobs in GitLab CI
  ci: create script to set up Git for Windows SDK
  t7300: work around platform-specific behaviour with long paths on MinGW

Commands that can also work outside Git have learned to take the
repository instance "repo" when we know we are in a repository, and
NULL when we are not, in a parameter.  The uses of the_repository
variable in a few of them have been removed using the new calling
convention.

* jc/a-commands-without-the-repo:
  archive: remove the_repository global variable
  annotate: remove usage of the_repository global
  git: pass in repo to builtin based on setup_git_directory_gently

Implements a new reftable-specific strbuf replacement to reduce
reftable's dependency on Git-specific data structures.

* ps/reftable-strbuf:
  reftable: handle trivial `reftable_buf` errors
  reftable/stack: adapt `stack_filename()` to handle allocation failures
  reftable/record: adapt `reftable_record_key()` to handle allocation failures
  reftable/stack: adapt `format_name()` to handle allocation failures
  t/unit-tests: check for `reftable_buf` allocation errors
  reftable/blocksource: adapt interface name
  reftable: convert from `strbuf` to `reftable_buf`
  reftable/basics: provide new `reftable_buf` interface
  reftable: stop using `strbuf_addf()`
  reftable: stop using `strbuf_addbuf()`

Teaches the ref-filter machinery to recognize and avoid cases where
sorting would be redundant.

* ps/ref-filter-sort:
  ref-filter: format iteratively with lexicographic refname sorting

Various platform compatibility fixes split out of the larger effort
to use Meson as the primary build tool.

* ps/platform-compat-fixes:
  http: fix build error on FreeBSD
  builtin/credential-cache: fix missing parameter for stub function
  t7300: work around platform-specific behaviour with long paths on MinGW
  t5500, t5601: skip tests which exercise paths with '[::1]' on Cygwin
  t3404: work around platform-specific behaviour on macOS 10.15
  t1401: make invocation of tar(1) work with Win32-provided one
  t/lib-gpg: fix setup of GNUPGHOME in MinGW
  t/lib-gitweb: test against the build version of gitweb
  t/test-lib: wire up NO_ICONV prerequisite
  t/test-lib: fix quoting of TEST_RESULTS_SAN_FILE

Start working to make the codebase buildable with -Wsign-compare.

* ps/build-sign-compare:
  t/helper: don't depend on implicit wraparound
  scalar: address -Wsign-compare warnings
  builtin/patch-id: fix type of `get_one_patchid()`
  builtin/blame: fix type of `length` variable when emitting object ID
  gpg-interface: address -Wsign-comparison warnings
  daemon: fix type of `max_connections`
  daemon: fix loops that have mismatching integer types
  global: trivial conversions to fix `-Wsign-compare` warnings
  pkt-line: fix -Wsign-compare warning on 32 bit platform
  csum-file: fix -Wsign-compare warning on 32-bit platform
  diff.h: fix index used to loop through unsigned integer
  config.mak.dev: drop `-Wno-sign-compare`
  global: mark code units that generate warnings with `-Wsign-compare`
  compat/win32: fix -Wsign-compare warning in "wWinMain()"
  compat/regex: explicitly ignore "-Wsign-compare" warnings
  git-compat-util: introduce macros to disable "-Wsign-compare" warnings

Regression fix for 'show-index' when run outside of a repository.

* as/show-index-uninitialized-hash:
  t5300: add test for 'show-index --object-format'
  show-index: fix uninitialized hash function

Build fixes for Windows.

* js/ps-build-cmake-fixup:
  cmake/vcxproj: stop special-casing `remote-ext`
  cmake: put the Perl modules into the correct location again
  cmake: use the correct file name for the Perl header
  cmake(mergetools): better support for out-of-tree builds
  cmake: better support for out-of-tree builds follow-up

Revert recent changes to the way windows environment is set up for
GitHub CI.

* js/github-windows-setup-fix:
  GitHub ci(windows): speed up initializing Git for Windows' minimal SDK again

Update the way rename() emulation on Windows handle directories to
correct an earlier attempt to do the same.

* js/mingw-rename-fix:
  mingw_rename: do support directory renames

The meson-build procedure is integrated into CI to catch and
prevent bitrotting.

* ps/ci-meson:
  ci: wire up Meson builds
  t: introduce compatibility options to clar-based tests
  t: fix out-of-tree tests for some git-p4 tests
  Makefile: detect missing Meson tests
  meson: detect missing tests at configure time
  t/unit-tests: rename clar-based unit tests to have a common prefix
  Makefile: drop -DSUPPRESS_ANNOTATED_LEAKS
  ci/lib: support custom output directories when creating test artifacts

"git refs migrate" learned to also migrate the reflog data across
backends.

* kn/reflog-migration:
  refs: add support for migrating reflogs
  refs: allow multiple reflog entries for the same refname
  refs: introduce the `ref_transaction_update_reflog` function
  refs: add `committer_info` to `ref_transaction_add_update()`
  refs: extract out refname verification in transactions
  refs/files: add count field to ref_lock
  refs: add `index` field to `struct ref_udpate`
  refs: include committer info in `ref_update` struct

"git range-diff" learned to optionally show and compare merge
commits in the ranges being compared, with the --diff-merges
option.

* js/range-diff-diff-merges:
  range-diff: introduce the convenience option `--remerge-diff`
  range-diff: optionally include merge commits' diffs in the analysis

Code clean-up.

* sk/calloc-not-malloc-plus-memset:
  git: use calloc instead of malloc + memset where possible

meson-based build still tried to build and install gitweb even when
Perl is disabled, which has been corrected.

* ps/build-meson-gitweb:
  meson: skip gitweb build when Perl is disabled

Type clean-up.

* jk/prio-queue-sign-compare-fix:
  prio-queue: use size_t rather than int for size

Code to reuse objects based on bitmap contents have been tightened
to avoid race condition even when multiple packs are involved.

* tb/bitmap-fix-pack-reuse:
  pack-bitmap.c: ensure pack validity for all reuse packs

Build fix.

* kl/doc-build-fix:
  doc: remove extra quotes in generated docs

"git submodule" learned various ways to spell the same option,
e.g. "--branch=B" can be spelled "--branch B" or "-bB".

* re/submodule-parse-opt:
  git-submodule.sh: rename some variables
  git-submodule.sh: improve variables readability
  git-submodule.sh: add some comments
  git-submodule.sh: get rid of unused variable
  git-submodule.sh: get rid of isnumber
  git-submodule.sh: improve parsing of short options
  git-submodule.sh: improve parsing of some long options

Recent reftable updates mistook a NULL return from a request for
0-byte allocation as OOM and died unnecessarily, which has been
corrected.

* ps/reftable-alloc-failures-zalloc-fix:
  reftable/basics: return NULL on zero-sized allocations
  reftable/stack: fix zero-sized allocation when there are no readers
  reftable/merged: fix zero-sized allocation when there are no readers
  reftable/stack: don't perform auto-compaction with less than two tables

A topic to optionally build with meson, which has graduated to
'master' recently, has regressed the normal Makefile build, which
is being corrected.

* ps/build-hotfix:
  meson: add options to override build information
  GIT-VERSION-GEN: fix overriding GIT_BUILT_FROM_COMMIT and GIT_DATE
  GIT-VERSION-GEN: fix overriding GIT_VERSION
  Makefile: introduce template for GIT-VERSION-GEN
  Makefile: drop unneeded indirection for GIT-VERSION-GEN outputs
  Makefile: stop including "GIT-VERSION-FILE" in docs

A topic to optionally build with meson, which has graduated to
'master' recently, broke Documentation pipeline with asciidoctor
for the normal Makefile build as well as meson-based one, which
have been corrected.

* ma/asciidoctor-build-fixes:
  asciidoctor-extensions.rb.in: inject GIT_DATE
  asciidoctor-extensions.rb.in: add missing word
  asciidoctor-extensions.rb.in: delete existing <refmiscinfo/>

"git refs migrate" learned to also migrate the reflog data across
backends.

* kn/reflog-migration:
  refs: mark invalid refname message for translation

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