Developer support update.

* es/check-non-portable-pre-5.10:
  check-non-portable-shell: support Perl versions older than 5.10

Doc update.

* ds/trace2-document-env-vars:
  trace2: add variable description to git.txt

The fsmonitor interface got out of sync after the in-core index
file gets discarded, which has been corrected.

* js/fsmonitor-refresh-after-discarding-index:
  fsmonitor: force a refresh after the index was discarded
  fsmonitor: demonstrate that it is not refreshed after discard_index()

A stale in-code comment has been updated.

* cm/notes-comment-fix:
  notes: correct documentation of format_display_notes()

Code cleanup.

* tt/no-ipv6-fallback-for-winxp:
  mingw: remove obsolete IPv6-related code

An additional test for MinGW

* js/t5580-unc-alternate-test:
  t5580: verify that alternates can be UNC paths

"git cvsexportcommit" running on msys did not expect cvsnt showed
"cvs status" output with CRLF line endings.

* ds/cvsexportcommit-force-text:
  cvsexportcommit: force crlf translation

To run tests for Git SVN, our scripts for CI used to install the
git-svn package (in the hope that it would bring in the right
dependencies).  This has been updated to install the more direct
dependency, namely, libsvn-perl.

* sg/ci-libsvn-perl:
  ci: install 'libsvn-perl' instead of 'git-svn'

Avoid patterns to pipe output from a git command to feed another
command in tests.

* bl/t4253-exit-code-from-format-patch:
  t4253-am-keep-cr-dos: avoid using pipes

The code to generate the multi-pack idx file was not prepared to
see too many packfiles and ran out of open file descriptor, which
has been corrected.

* ds/midx-too-many-packs:
  midx: add packs to packed_git linked list
  midx: pass a repository pointer

On a filesystem like HFS+, the names of the refs stored as filesystem
entities may become different from what the end-user expects, just
like files in the working tree get "renamed".  Work around the
mismatch by paying attention to the core.precomposeUnicode
configuration.

* en/unicode-in-refnames:
  Honor core.precomposeUnicode in more places

Update "git difftool" and "git mergetool" so that the combinations
of {diff,merge}.{tool,guitool} configuration variables serve as
fallback settings of each other in a sensible order.

* dl/difftool-mergetool:
  difftool: fallback on merge.guitool
  difftool: make --gui, --tool and --extcmd mutually exclusive
  mergetool: fallback to tool when guitool unavailable
  mergetool--lib: create gui_mode function
  mergetool: use get_merge_tool function
  t7610: add mergetool --gui tests
  t7610: unsuppress output

A pair of private functions in http.c that had names similar to
fread/fwrite did not return the number of elements, which was found
to be confusing.

* mh/http-fread-api-fix:
  Make fread/fwrite-like functions in http.c more like fread/fwrite.

Future-proof a test against an update to MSYS2 runtime v3.x series.

* js/t6500-use-windows-pid-on-mingw:
  t6500(mingw): use the Windows PID of the shell

Allow tests that involve httpd to be run under leak sanitizer, just
like we can already do so under address sanitizer.

* jk/apache-lsan:
  t/lib-httpd: pass LSAN_OPTIONS through apache

Attempt to use an abbreviated option in "git clone --recurs" is
responded by a request to disambiguate between --recursive and
--recurse-submodules, which is bad because these two are synonyms.
The parse-options API has been extended to define such synonyms
more easily and not produce an unnecessary failure.

* nd/parse-options-aliases:
  parse-options: don't emit "ambiguous option" for aliases

"git branch new A...B" and "git checkout -b new A...B" have been
taught that in their contexts, the notation A...B means "the merge
base between these two commits", just like "git checkout A...B"
detaches HEAD at that commit.

* dl/branch-from-3dot-merge-base:
  branch: make create_branch accept a merge base rev
  t2018: cleanup in current test

Leakfix.

* js/commit-graph-parse-leakfix:
  commit-graph: fix memory leak

Optionally "make coccicheck" can feed multiple source files to
spatch, gaining performance while spending more memory.

* jk/cocci-batch:
  coccicheck: make batch size of 0 mean "unlimited"
  coccicheck: optionally batch spatch invocations

Performance test framework has been broken and measured the version
of Git that happens to be on $PATH, not the specified one to
measure, for a while, which has been corrected.

* ab/perf-installed-fix:
  perf-lib.sh: forbid the use of GIT_TEST_INSTALLED
  perf tests: add "bindir" prefix to git tree test results
  perf-lib.sh: remove GIT_TEST_INSTALLED from perf-lib.sh
  perf-lib.sh: make "./run <revisions>" use the correct gits
  perf aggregate: remove GIT_TEST_INSTALLED from --codespeed
  perf README: correct docs for 3c8f12c9 regression

Allow DEP and ASLR for Windows build to for security hardening.

* id/windows-dep-aslr:
  mingw: enable DEP and ASLR
  mingw: do not let ld strip relocations

Typofix.

* ab/trace2-typofix:
  trace2: fix up a missing "leave" entry point

Typofix.

* nd/submodule-helper-incomplete-line-fix:
  submodule--helper: add a missing \n

Portability fix for a diff-highlight tool (in contrib/).

* cw/diff-highlight:
  diff-highlight: use correct /dev/null for UNIX and Windows

Typofix.

* dl/warn-tagging-a-tag:
  tag: fix typo in nested tagging hint

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

A few embarrassing bugfixes.

* jh/trace2:
  trace2: fix up a missing "leave" entry point
  trace2: fix incorrect function pointer check

Workaround for standard-compliant but less-than-useful behaviour of
access(2) for the root user.

* cc/access-on-aix-workaround:
  git-compat-util: work around for access(X_OK) under root

"git chery-pick" (and "revert" that shares the same runtime engine)
that deals with multiple commits got confused when the final step
gets stopped with a conflict and the user concluded the sequence
with "git commit".  Attempt to fix it by cleaning up the state
files used by these commands in such a situation.

* pw/clean-sequencer-state-upon-final-commit:
  fix cherry-pick/revert status after commit
  commit/reset: try to clean up sequencer state

The internal implementation of "git rebase -i" has been updated to
avoid forking a separate "rebase--interactive" process.

* pw/rebase-i-internal:
  rebase -i: run without forking rebase--interactive
  rebase: use a common action enum
  rebase -i: use struct rebase_options in do_interactive_rebase()
  rebase -i: use struct rebase_options to parse args
  rebase -i: use struct object_id for squash_onto
  rebase -i: use struct commit when parsing options
  rebase -i: remove duplication
  rebase -i: combine rebase--interactive.c with rebase.c
  rebase: use OPT_RERERE_AUTOUPDATE()
  rebase: rename write_basic_state()
  rebase: don't translate trace strings
  sequencer: always discard index after checkout

The script to aggregate perf result unconditionally depended on
libjson-perl even though it did not have to, which has been
corrected.

* jk/perf-aggregate-wo-libjson:
  t/perf: depend on perl JSON only when using --codespeed

Docfix.

* dl/rev-tilde-doc-clarify:
  revisions.txt: remove ambibuity between <rev>:<path> and :<path>
  revisions.txt: mention <rev>~ form
  revisions.txt: mark optional rev arguments with []
  revisions.txt: change "rev" to "<rev>"

A "ls-files" that emulates "find" to enumerate files in the working
tree resulted in duplicated Makefile rules that caused the build to
issue an unnecessary warning during a trial build after merge
conflicts are resolved in working tree *.h files but before the
resolved results are added to the index.  This has been corrected.

* jc/make-dedup-ls-files-output:
  Makefile: dedup list of files obtained from ls-files

Docfix.

* jk/ls-files-doc-markup-fix:
  doc/ls-files: put nested list for "-t" option into block

Fix index-pack perf test so that the repeated invocations always
run in an empty repository, which emulates the initial clone
situation better.

* jk/p5302-avoid-collision-check-cost:
  p5302: create the repo in each index-pack test

Mechanically and systematically drop "extern" from function
declarlation.

* dl/no-extern-in-func-decl:
  *.[ch]: manually align parameter lists
  *.[ch]: remove extern from function declarations using sed
  *.[ch]: remove extern from function declarations using spatch

The connectivity bitmaps are created by default in bare
repositories now; also the pathname hash-cache is created by
default to avoid making crappy deltas when repacking.

* ew/repack-with-bitmaps-by-default:
  pack-objects: default to writing bitmap hash-cache
  t5310: correctly remove bitmaps for jgit test
  repack: enable bitmaps by default on bare repos

During an initial "git clone --depth=..." partial clone, it is
pointless to spend cycles for a large portion of the connectivity
check that enumerates and skips promisor objects (which by
definition is all objects fetched from the other side).  This has
been optimized out.

* js/partial-clone-connectivity-check:
  t/perf: add perf script for partial clones
  clone: do faster object check for partial clones

Polishing of the new trace2 facility continues.  The system-level
configuration can specify site-wide trace2 settings, which can be
overridden with per-user configuration and environment variables.

* jh/trace2-sid-fix:
  trace2: fixup access problem on /etc/gitconfig in read_very_early_config
  trace2: update docs to describe system/global config settings
  trace2: make SIDs more unique
  trace2: clarify UTC datetime formatting
  trace2: report peak memory usage of the process
  trace2: use system/global config for default trace2 settings
  config: add read_very_early_config()
  trace2: find exec-dir before trace2 initialization
  trace2: add absolute elapsed time to start event
  trace2: refactor setting process starting time
  config: initialize opts structure in repo_read_config()

In git-difftool.txt, it says

	'git difftool' falls back to 'git mergetool' config variables when the
	difftool equivalents have not been defined.

However, when `diff.guitool` is missing, it doesn't fallback to
anything. Make git-difftool fallback to `merge.guitool` when `diff.guitool` is
missing.
Signed-off-by: NDenton Liu <liu.denton@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>