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>

In git-difftool, these options specify which tool to ultimately run. As
a result, they are logically conflicting. Explicitly disallow these
options from being used together.
Signed-off-by: NDenton Liu <liu.denton@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In git-difftool, if the tool is called with --gui but `diff.guitool` is
not set, it falls back to `diff.tool`. Make git-mergetool also fallback
from `merge.guitool` to `merge.tool` if the former is undefined.

If git-difftool, when called with `--gui`, were to use
`get_configured_mergetool` in a future patch, it would also get the
fallback behavior in the following precedence:

1. diff.guitool
2. merge.guitool
3. diff.tool
4. merge.tool

The behavior for when difftool or mergetool are called without `--gui`
should be identical with or without this patch.

Note that the search loop could be written as

	sections="merge"
	keys="tool"
	if diff_mode
	then
		sections="diff $sections"
	fi
	if gui_mode
	then
		keys="guitool $keys"
	fi

	merge_tool=$(
		IFS=' '
		for key in $keys
		do
			for section in $sections
			do
				selected=$(git config $section.$key)
				if test -n "$selected"
				then
					echo "$selected"
					return
				fi
			done
		done)

which would make adding a mode in the future much easier. However,
adding a new mode will likely never happen as it is highly discouraged
so, as a result, it is written in its current form so that it is more
readable for future readers.
Signed-off-by: NDenton Liu <liu.denton@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Before, in `get_configured_merge_tool`, we would test the value of the
first argument directly, which corresponded to whether we were using
guitool. However, since `$GIT_MERGETOOL_GUI` is available as an
environment variable, create the `gui_mode` function which increases the
clarify of functions which use it.

While we're at it, add a space before `()` in function definitions to
fix the style.
Signed-off-by: NDenton Liu <liu.denton@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In git-mergetool, the logic for getting which merge tool to use is
duplicated in git-mergetool--lib, except for the fact that it needs to
know whether the tool was guessed or not.

Rewrite `get_merge_tool` to return whether or not the tool was guessed
through the return code and make git-mergetool call this function
instead of duplicating the logic. Note that 1 was chosen to be the
return code of when a tool is guessed because it seems like a slightly
more abnormal condition than getting a tool that's explicitly specified
but this is completely arbitrary.

Also, let `$GIT_MERGETOOL_GUI` be set to determine whether or not the
guitool will be selected.

This change is not completely backwards compatible as there may be
external users of git-mergetool--lib. However, only one user,
git-diffall[1], was found from searching GitHub and Google, and this
tool is superseded by `git difftool --dir-diff` anyway. It seems very
unlikely that there exists an external caller that would take into
account the return code of `get_merge_tool` as it would always return 0
before this change so this change probably does not affect any external
users.

[1]: https://github.com/thenigan/git-diffallSigned-off-by: NDenton Liu <liu.denton@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Fix a trivial bug that's been here since the shared/do_write_index
tracing was added in 42fee7a3 ("trace2:data: add trace2
instrumentation to index read/write", 2019-02-22). We should have
enter/leave points, not two enter/enter points. This resulted in an
"enter" event without a corresponding "leave" event.
Signed-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: NDerrick Stolee <dstolee@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Enable DEP (Data Execution Prevention) and ASLR (Address Space Layout
Randomization) support. This applies to both 32bit and 64bit builds
and makes it substantially harder to exploit security holes in Git by
offering a much more unpredictable attack surface.

ASLR interferes with GDB's ability to set breakpoints. A similar issue
holds true when compiling with -O2 (in which case single-stepping is
messed up because GDB cannot map the code back to the original source
code properly). Therefore we simply enable ASLR only when an
optimization flag is present in the CFLAGS, using it as an indicator
that the developer does not want to debug in GDB anyway.
Signed-off-by: Nİsmail Dönmez <ismail@i10z.com>
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This is the first step for enabling ASLR (Address Space Layout
Randomization) support. We want to enable ASLR for better protection
against exploiting security holes in Git: it makes it harder to attack
software by making code addresses unpredictable.

The problem fixed by this commit is that `ld.exe` seems to be stripping
relocations which in turn will break ASLR support. We just make sure
it's not stripping the main executable entry.
Signed-off-by: Nİsmail Dönmez <ismail@i10z.com>
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Fix a trivial bug that's been here since the shared/do_write_index
tracing was added in 42fee7a3 ("trace2:data: add trace2
instrumentation to index read/write", 2019-02-22). We should have
enter/leave points, not two enter/enter points. This resulted in an
"enter" event without a corresponding "leave" event.
Signed-off-by: NÆvar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: NDerrick Stolee <dstolee@microsoft.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In eea9c1e7 (tag: advise on nested tags, 2019-04-04), tag was taught
to hint at the user if a nested tag is made. However, this message had a
typo and it said "The object referred to by your new is...", which was
missing a "tag" after "new". Fix this message by adding the "tag".
Signed-off-by: NDenton Liu <liu.denton@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>