"git fetch $repo $object" in a partial clone did not correctly
fetch the asked-for object that is referenced by an object in
promisor packfile, which has been fixed.

* jt/fetch-tips-in-partial-clone:
  fetch: in partial clone, check presence of targets
  connected: document connectivity in partial clones

"git status" learns to show progress bar when refreshing the index
takes a long time.

* nd/status-refresh-progress:
  status: show progress bar if refreshing the index takes too long

A new extension to the index file has been introduced, which allows
the file to be read in parallel.

* bp/read-cache-parallel:
  read-cache: load cache entries on worker threads
  ieot: add Index Entry Offset Table (IEOT) extension
  read-cache: load cache extensions on a worker thread
  config: add new index.threads config setting
  eoie: add End of Index Entry (EOIE) extension
  read-cache: clean up casting and byte decoding
  read-cache.c: optimize reading index format v4

Some environment variables that control the runtime options of Git
used during tests are getting renamed for consistency.

* bp/rename-test-env-var:
  t0000: do not get self-test disrupted by environment warnings
  preload-index: update GIT_FORCE_PRELOAD_TEST support
  read-cache: update TEST_GIT_INDEX_VERSION support
  fsmonitor: update GIT_TEST_FSMONITOR support
  preload-index: use git_env_bool() not getenv() for customization
  t/README: correct spelling of "uncommon"

Code clean-up in the internal machinery used by "git status" and
"git commit --dry-run".

* ss/wt-status-committable:
  roll wt_status_state into wt_status and populate in the collect phase
  wt-status.c: set the committable flag in the collect phase
  t7501: add test of "commit --dry-run --short"
  wt-status: rename commitable to committable
  wt-status.c: move has_unmerged earlier in the file

Various codepaths in the core-ish part learn to work on an
arbitrary in-core index structure, not necessarily the default
instance "the_index".

* nd/the-index: (23 commits)
  revision.c: reduce implicit dependency the_repository
  revision.c: remove implicit dependency on the_index
  ws.c: remove implicit dependency on the_index
  tree-diff.c: remove implicit dependency on the_index
  submodule.c: remove implicit dependency on the_index
  line-range.c: remove implicit dependency on the_index
  userdiff.c: remove implicit dependency on the_index
  rerere.c: remove implicit dependency on the_index
  sha1-file.c: remove implicit dependency on the_index
  patch-ids.c: remove implicit dependency on the_index
  merge.c: remove implicit dependency on the_index
  merge-blobs.c: remove implicit dependency on the_index
  ll-merge.c: remove implicit dependency on the_index
  diff-lib.c: remove implicit dependency on the_index
  read-cache.c: remove implicit dependency on the_index
  diff.c: remove implicit dependency on the_index
  grep.c: remove implicit dependency on the_index
  diff.c: remove the_index dependency in textconv() functions
  blame.c: rename "repo" argument to "r"
  combine-diff.c: remove implicit dependency on the_index
  ...

Teach bash completion that "git fetch --multiple" only takes remote
names as arguments and no refspecs.

* nd/complete-fetch-multiple-args:
  completion: support "git fetch --multiple"

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

The completion script (in contrib/) learned to complete a handful of
options "git stash list" command takes.

* sf/complete-stash-list:
  git-completion.bash: add completion for stash list

Typofixes.

* mw/doc-typofixes:
  docs: typo: s/isimilar/similar/
  docs: graph: remove unnecessary `graph_update()' call
  docs: typo: s/go/to/

The minimum version of Windows supported by Windows port fo Git is
now set to Vista.

* js/mingw-wants-vista-or-above:
  mingw: bump the minimum Windows version to Vista
  mingw: set _WIN32_WINNT explicitly for Git for Windows
  compat/poll: prepare for targeting Windows Vista

Code clean-up.

* rs/sequencer-oidset-insert-avoids-dups:
  sequencer: use return value of oidset_insert()

Code clean-up.

* jk/oideq-hasheq-cleanup:
  more oideq/hasheq conversions

Doc update.

* ma/mailing-list-address-in-git-help:
  git doc: direct bug reporters to mailing list archive

Doc update.

* nd/packobjectshook-doc-fix:
  config.txt: correct the note about uploadpack.packObjectsHook

Typofix.

* rt/rebase-typofix:
  git-rebase.sh: fix typos in error messages

Test fix.

* ma/t1400-undebug-test:
  t1400: drop debug `echo` to actually execute `test`

Doc update.

* ma/commit-graph-docs:
  Doc: refer to the "commit-graph file" with dash
  git-commit-graph.txt: refer to "*commit*-graph file"
  git-commit-graph.txt: typeset more in monospace
  git-commit-graph.txt: fix bullet lists

Doc update.

* dz/credential-doc-url-matching-rules:
  doc: clarify gitcredentials path component matching

The code in "git status" sometimes hit an assertion failure.  This
was caused by a structure that was reused without cleaning the data
used for the first run, which has been corrected.

* en/status-multiple-renames-to-the-same-target-fix:
  commit: fix erroneous BUG, 'multiple renames on the same target? how?'

Code already in 'master' is further cleaned-up by this patch.

* ds/reachable-final-cleanup:
  commit-reach: cleanups in can_all_from_reach...

Comment fix.

* jk/check-everything-connected-is-long-gone:
  receive-pack: update comment with check_everything_connected

"gc --auto" ended up calling exit(-1) upon error, which has been
corrected to use exit(1).  Also the error reporting behaviour when
daemonized has been updated to exit with zero status when stopping
due to a previously discovered error (which implies there is no
point running gc to improve the situation); we used to exit with
failure in such a case.

* jn/gc-auto:
  gc: do not return error for prior errors in daemonized mode

Code clean-up.

* jn/gc-auto-prep:
  gc: exit with status 128 on failure
  gc: improve handling of errors reading gc.log

Various test scripts have been updated for style and also correct
handling of exit status of various commands.

* md/test-cleanup:
  tests: order arguments to git-rev-list properly
  t9109: don't swallow Git errors upstream of pipes
  tests: don't swallow Git errors upstream of pipes
  t/*: fix ordering of expected/observed arguments
  tests: standardize pipe placement
  Documentation: add shell guidelines
  t/README: reformat Do, Don't, Keep in mind lists

Doc updates.

* fe/doc-updates:
  git-describe.1: clarify that "human readable" is also git-readable
  git-column.1: clarify initial description, provide examples
  git-archimport.1: specify what kind of Arch we're talking about

The mailmap file update.

* jn/mailmap-update:
  mailmap: consistently normalize brian m. carlson's name

Test update.

* tg/t5551-with-curl-7.61.1:
  t5551: compare sorted cookies files
  t5551: move setup code inside test_expect blocks

Code clean-up.

* en/merge-cleanup:
  merge-recursive: rename merge_file_1() and merge_content()
  merge-recursive: remove final remaining caller of merge_file_one()
  merge-recursive: avoid wrapper function when unnecessary and wasteful
  merge-recursive: set paths correctly when three-way merging content

Header files clean-up.

* rj/header-check:
  delta-islands.h: add missing forward declarations (hdr-check)
  midx.h: add missing forward declarations (hdr-check)
  refs/refs-internal.h: add missing declarations (hdr-check)
  refs/packed-backend.h: add missing declaration (hdr-check)
  refs/ref-cache.h: add missing declarations (hdr-check)
  ewah/ewok_rlw.h: add missing include (hdr-check)
  json-writer.h: add missing include (hdr-check)
  Makefile: add a hdr-check target

Doc update.

* ma/config-doc-update:
  git-config.txt: fix 'see: above' note
  Doc: use `--type=bool` instead of `--bool`

Fix interactions between two recent topics.

* jk/delta-islands-with-bitmap-reuse-delta-fix:
  pack-objects: handle island check for "external" delta base

Fix for typo in a sample code in comment.

* tq/refs-internal-comment-fix:
  refs: docstring typo

An alias that expands to another alias has so far been forbidden,
but now it is allowed to create such an alias.

* ts/alias-of-alias:
  t0014: introduce an alias testing suite
  alias: show the call history when an alias is looping
  alias: add support for aliases of an alias

The recently introduced commit-graph auxiliary data is incompatible
with mechanisms such as replace & grafts that "breaks" immutable
nature of the object reference relationship.  Disable optimizations
based on its use (and updating existing commit-graph) when these
incompatible features are in use in the repository.

* ds/commit-graph-with-grafts:
  commit-graph: close_commit_graph before shallow walk
  commit-graph: not compatible with uninitialized repo
  commit-graph: not compatible with grafts
  commit-graph: not compatible with replace objects
  test-repository: properly init repo
  commit-graph: update design document
  refs.c: upgrade for_each_replace_ref to be a each_repo_ref_fn callback
  refs.c: migrate internal ref iteration to pass thru repository argument

Generation of (experimental) commit-graph files have so far been
fairly silent, even though it takes noticeable amount of time in a
meaningfully large repository.  The users will now see progress
output.

* ab/commit-graph-progress:
  gc: fix regression in 7b0f2292 impacting --quiet
  commit-graph verify: add progress output
  commit-graph write: add progress output

This patch helps address the CPU cost of loading the index by utilizing
the Index Entry Offset Table (IEOT) to divide loading and conversion of
the cache entries across multiple threads in parallel.

I used p0002-read-cache.sh to generate some performance data:

Test w/100,000 files reduced the time by 32.24%
Test w/1,000,000 files reduced the time by -4.77%

Note that on the 1,000,000 files case, multi-threading the cache entry parsing
does not yield a performance win.  This is because the cost to parse the
index extensions in this repo, far outweigh the cost of loading the cache
entries.

The high cost of parsing the index extensions is driven by the cache tree
and the untracked cache extensions. As this is currently the longest pole,
any reduction in this time will reduce the overall index load times so is
worth further investigation in another patch series.
Signed-off-by: NBen Peart <benpeart@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This patch enables addressing the CPU cost of loading the index by adding
additional data to the index that will allow us to efficiently multi-
thread the loading and conversion of cache entries.

It accomplishes this by adding an (optional) index extension that is a
table of offsets to blocks of cache entries in the index file.  To make
this work for V4 indexes, when writing the cache entries, it periodically
"resets" the prefix-compression by encoding the current entry as if the
path name for the previous entry is completely different and saves the
offset of that entry in the IEOT.  Basically, with V4 indexes, it
generates offsets into blocks of prefix-compressed entries.
Signed-off-by: NBen Peart <benpeart@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This patch helps address the CPU cost of loading the index by loading
the cache extensions on a worker thread in parallel with loading the cache
entries.

In some cases, loading the extensions takes longer than loading the
cache entries so this patch utilizes the new EOIE to start the thread to
load the extensions before loading all the cache entries in parallel.

This is possible because the current extensions don't access the cache
entries in the index_state structure so are OK that they don't all exist
yet.

The CACHE_EXT_TREE, CACHE_EXT_RESOLVE_UNDO, and CACHE_EXT_UNTRACKED
extensions don't even get a pointer to the index so don't have access to the
cache entries.

CACHE_EXT_LINK only uses the index_state to initialize the split index.
CACHE_EXT_FSMONITOR only uses the index_state to save the fsmonitor last
update and dirty flags.

I used p0002-read-cache.sh to generate some performance data:

	Test w/100,000 files reduced the time by 0.53%
	Test w/1,000,000 files reduced the time by 27.78%
Signed-off-by: NBen Peart <benpeart@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add support for a new index.threads config setting which will be used to
control the threading code in do_read_index().  A value of 0 will tell the
index code to automatically determine the correct number of threads to use.
A value of 1 will make the code single threaded.  A value greater than 1
will set the maximum number of threads to use.

For testing purposes, this setting can be overwritten by setting the
GIT_TEST_INDEX_THREADS=<n> environment variable to a value greater than 0.
Signed-off-by: NBen Peart <benpeart@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>