Doc update.

* cw/protocol-v2-doc-fix:
  protocol-v2.txt: align delim-pkt spec with usage

Ensure that the sparseness of the in-core index matches the
index.sparse configuration specified by the repository immediately
after the on-disk index file is read.

* vd/sparse-sparsity-fix-on-read:
  sparse-index: update do_read_index to ensure correct sparsity
  sparse-index: add ensure_correct_sparsity function
  sparse-index: avoid unnecessary cache tree clearing
  test-read-cache.c: prepare_repo_settings after config init

Code clean-up to eventually allow information on remotes defined
for an arbitrary repository to be read.

* gc/remote-with-fewer-static-global-variables:
  remote: die if branch is not found in repository
  remote: remove the_repository->remote_state from static methods
  remote: use remote_state parameter internally
  remote: move static variables into per-repository struct
  t5516: add test case for pushing remote refspecs

Doc update.

* ja/doc-cleanup:
  init doc: --shared=0xxx does not give umask but perm bits
  doc: git-init: clarify file modes in octal.
  doc: git-http-push: describe the refs as pattern pairs
  doc: uniformize <URL> placeholders' case
  doc: use three dots for indicating repetition instead of star
  doc: git-ls-files: express options as optional alternatives
  doc: use only hyphens as word separators in placeholders
  doc: express grammar placeholders between angle brackets
  doc: split placeholders as individual tokens
  doc: fix git credential synopsis

Redact the path part of packfile URI that appears in the trace output.

* if/redact-packfile-uri:
  http-fetch: redact url on die() message
  fetch-pack: redact packfile urls in traces

Doc update.

* jc/fix-first-object-walk:
  docs: add headers in MyFirstObjectWalk
  docs: fix places that break compilation in MyFirstObjectWalk

CI has been taught to catch some Unicode directional formatting
sequence that can be used in certain mischief.

* js/ci-no-directional-formatting:
  ci: disallow directional formatting

The "--date=format:<strftime>" gained a workaround for the lack of
system support for a non-local timezone to handle "%s" placeholder.

* jk/strbuf-addftime-seconds-since-epoch:
  strbuf_addftime(): handle "%s" manually

"git var GIT_DEFAULT_BRANCH" is a way to see what name is used for
the newly created branch if "git init" is run.

* tw/var-default-branch:
  var: add GIT_DEFAULT_BRANCH variable

Build optimization.

* ab/generate-command-list:
  generate-cmdlist.sh: don't parse command-list.txt thrice
  generate-cmdlist.sh: replace "grep' invocation with a shell version
  generate-cmdlist.sh: do not shell out to "sed"
  generate-cmdlist.sh: stop sorting category lines
  generate-cmdlist.sh: replace for loop by printf's auto-repeat feature
  generate-cmdlist.sh: run "grep | sort", not "sort | grep"
  generate-cmdlist.sh: don't call get_categories() from category_list()
  generate-cmdlist.sh: spawn fewer processes
  generate-cmdlist.sh: trivial whitespace change
  command-list.txt: sort with "LC_ALL=C sort"

Tighten code for testing pack-bitmap.

* jk/test-bitmap-fix:
  test_bitmap_hashes(): handle repository without bitmaps

The "merge" subcommand of "git jump" (in contrib/) silently ignored
pathspec and other parameters.

* jk/jump-merge-with-pathspec:
  git-jump: pass "merge" arguments to ls-files

The code to decode the length of packed object size has been
corrected.

* jt/pack-header-lshift-overflow:
  packfile: avoid overflowing shift during decode

"diff --histogram" optimization.

* pw/xdiff-classify-record-in-histogram:
  xdiff: simplify comparison
  xdiff: avoid unnecessary memory allocations
  diff histogram: intern strings

trace2 error code path fix.

* js/trace2-avoid-recursive-errors:
  trace2: disable tr2_dst before warning on write errors

Test fix.

* jk/t5319-midx-corruption-test-deflake:
  t5319: corrupt more bytes of the midx checksum

Leakfix.

* ab/checkout-branch-info-leakfix:
  checkout: fix "branch info" memory leaks

…ge' into next

The advice message given by "git pull" when the user hasn't made a
choice between merge and rebase still said that the merge is the
default, which no longer is the case.  This has been corrected.

* ah/advice-pull-has-no-preference-between-rebase-and-merge:
  pull: don't say that merge is "the default strategy"

Bitop fix for platforms whose "long" is 32-bit.

* rs/mergesort:
  mergesort: avoid left shift overflow

* po/size-t-for-vs:
  object-file.c: LLP64 compatibility, upcast unity for left shift
  diffcore-delta.c: LLP64 compatibility, upcast unity for left shift
  repack.c: LLP64 compatibility, upcast unity for left shift

Doc mark-up fix.

* tl/midx-docfix:
  midx: fix a formatting issue in "multi-pack-index.txt"

Various operating modes of "git reset" have been made to work
better with the sparse index.

* vd/sparse-reset:
  unpack-trees: improve performance of next_cache_entry
  reset: make --mixed sparse-aware
  reset: make sparse-aware (except --mixed)
  reset: integrate with sparse index
  reset: expand test coverage for sparse checkouts
  sparse-index: update command for expand/collapse test
  reset: preserve skip-worktree bit in mixed reset
  reset: rename is_missing to !is_in_reset_tree

Comment fix.

* hk/ci-checkwhitespace-commentfix:
  ci(check-whitespace): update stale file top comments

"git fetch", when received a bad packfile, can fail with SIGPIPE.
This wasn't wrong per-se, but we now detect the situation and fail
in a more predictable way.

* jk/fetch-pack-avoid-sigpipe-to-index-pack:
  fetch-pack: ignore SIGPIPE when writing to index-pack

Workaround for a false-alarm by gcc-11

* jk/refs-g11-workaround:
  refs: work around gcc-11 warning with REF_HAVE_NEW

The function to cull a child process and determine the exit status
had two separate code paths for normal callers and callers in a
signal handler, and the latter did not yield correct value when the
child has caught a signal.  The handling of the exit status has
been unified for these two code paths.  An existing test with
flakiness has also been corrected.

* jk/t7006-sigpipe-tests-fix:
  t7006: simplify exit-code checks for sigpipe tests
  t7006: clean up SIGPIPE handling in trace2 tests
  run-command: unify signal and regular logic for wait_or_whine()

Docfix.

* jt/midx-doc-fix:
  Doc: no midx and partial clone relation

A small simplification of API.

* hn/create-reflog-simplify:
  refs: drop force_create argument of create_reflog API

Weather balloon to break people with compilers that do not support
C99.

* bc/require-c99:
  git-compat-util: add a test balloon for C99 support

The "reftable" backend for the refs API, without integrating into
the refs subsystem, has been added.

* hn/reftable:
  Add "test-tool dump-reftable" command.
  reftable: add dump utility
  reftable: implement stack, a mutable database of reftable files.
  reftable: implement refname validation
  reftable: add merged table view
  reftable: add a heap-based priority queue for reftable records
  reftable: reftable file level tests
  reftable: read reftable files
  reftable: generic interface to tables
  reftable: write reftable files
  reftable: a generic binary tree implementation
  reftable: reading/writing blocks
  Provide zlib's uncompress2 from compat/zlib-compat.c
  reftable: (de)serialization for the polymorphic record type.
  reftable: add blocksource, an abstraction for random access reads
  reftable: utility functions
  reftable: add error related functionality
  reftable: add LICENSE
  hash.h: provide constants for the hash IDs

This is just string_list_split() copy/pasted with the "push" part
adjusted. The next commit will call this function to parse a line of
command arguments.

Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: John Cai <johncai86@gmail.com>

Teach cat-file to accept a --stdin-cmd which causes cat-file to enter a
command mode to receive commands and arguments on stdin..

batch_objects_stdin_cmd() handles a line from stdin, which it expects a
command name and arguments. -z will tell --stdin-cmd to look for NUL
as the line termination.

This commit adds two commands, fflush and object. fflush immediately
flushes the buffer. object takes a sha as an argument and passes it to
batch_one_object().

The code allows for additional commands to be added as parse_cmd structs.

Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: John Cai <johncai86@gmail.com>