48 files changed, 906 insertions, 49 deletions
diff --git a/contrib/buildsystems/CMakeLists.txt b/contrib/buildsystems/CMakeLists.txt
index 10dc54fdcb..25b495fa73 100644
--- a/contrib/buildsystems/CMakeLists.txt
+++ b/contrib/buildsystems/CMakeLists.txt
@@ -1001,10 +1001,14 @@ parse_makefile_for_sources(unit-test_SOURCES ${CMAKE_SOURCE_DIR}/Makefile "UNIT_
 list(TRANSFORM unit-test_SOURCES REPLACE "\\$\\(UNIT_TEST_DIR\\)/" "${CMAKE_SOURCE_DIR}/t/unit-tests/")
 add_library(unit-test-lib STATIC ${unit-test_SOURCES})
 
+parse_makefile_for_sources(clar-test_SOURCES ${CMAKE_SOURCE_DIR}/Makefile "CLAR_TEST_OBJS")
+list(TRANSFORM clar-test_SOURCES REPLACE "\\$\\(UNIT_TEST_DIR\\)/" "${CMAKE_SOURCE_DIR}/t/unit-tests/")
+add_library(clar-test-lib STATIC ${clar-test_SOURCES})
+
 parse_makefile_for_scripts(unit_test_PROGRAMS "UNIT_TEST_PROGRAMS" "")
 foreach(unit_test ${unit_test_PROGRAMS})
 	add_executable("${unit_test}" "${CMAKE_SOURCE_DIR}/t/unit-tests/${unit_test}.c")
-	target_link_libraries("${unit_test}" unit-test-lib common-main)
+	target_link_libraries("${unit_test}" unit-test-lib clar-test-lib common-main)
 	set_target_properties("${unit_test}"
 		PROPERTIES RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/t/unit-tests/bin)
 	if(MSVC)
@@ -1046,13 +1050,13 @@ add_custom_command(OUTPUT "${CMAKE_BINARY_DIR}/t/unit-tests/clar.suite"
 	VERBATIM)
 
 add_library(unit-tests-lib ${clar_test_SUITES}
-	"${CMAKE_SOURCE_DIR}/t/unit-tests/clar/clar.c"
 	"${CMAKE_BINARY_DIR}/t/unit-tests/clar-decls.h"
 	"${CMAKE_BINARY_DIR}/t/unit-tests/clar.suite"
 )
+target_include_directories(clar-test-lib PUBLIC "${CMAKE_BINARY_DIR}/t/unit-tests")
 target_include_directories(unit-tests-lib PUBLIC "${CMAKE_BINARY_DIR}/t/unit-tests")
-add_executable(unit-tests "${CMAKE_SOURCE_DIR}/t/unit-tests/unit-test.c")
-target_link_libraries(unit-tests unit-tests-lib common-main)
+add_executable(unit-tests)
+target_link_libraries(unit-tests unit-tests-lib clar-test-lib common-main)
 set_target_properties(unit-tests
 	PROPERTIES RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/t/unit-tests/bin)
 if(MSVC)
@@ -1169,14 +1173,13 @@ string(REPLACE "@GIT_PERF_MAKE_COMMAND@" "" git_build_options "${git_build_optio
 string(REPLACE "@GIT_PERF_MAKE_OPTS@" "" git_build_options "${git_build_options}")
 string(REPLACE "@GIT_PERF_REPEAT_COUNT@" "" git_build_options "${git_build_options}")
 string(REPLACE "@GIT_PERF_REPO@" "" git_build_options "${git_build_options}")
+string(REPLACE "@GIT_SOURCE_DIR@" "${CMAKE_SOURCE_DIR}" git_build_options "${git_build_options}")
 string(REPLACE "@GIT_TEST_CMP@" "" git_build_options "${git_build_options}")
 string(REPLACE "@GIT_TEST_CMP_USE_COPIED_CONTEXT@" "" git_build_options "${git_build_options}")
 string(REPLACE "@GIT_TEST_GITPERLLIB@" "'${CMAKE_BINARY_DIR}/perl/build/lib'" git_build_options "${git_build_options}")
 string(REPLACE "@GIT_TEST_INDEX_VERSION@" "" git_build_options "${git_build_options}")
-string(REPLACE "@GIT_TEST_MERGE_TOOLS_DIR@" "'${CMAKE_BINARY_DIR}/mergetools'" git_build_options "${git_build_options}")
 string(REPLACE "@GIT_TEST_OPTS@" "" git_build_options "${git_build_options}")
 string(REPLACE "@GIT_TEST_PERL_FATAL_WARNINGS@" "" git_build_options "${git_build_options}")
-string(REPLACE "@GIT_TEST_POPATH@" "'${CMAKE_BINARY_DIR}/po'" git_build_options "${git_build_options}")
 string(REPLACE "@GIT_TEST_TEMPLATE_DIR@" "'${CMAKE_BINARY_DIR}/templates/blt'" git_build_options "${git_build_options}")
 string(REPLACE "@GIT_TEST_TEXTDOMAINDIR@" "'${CMAKE_BINARY_DIR}/po/build/locale'" git_build_options "${git_build_options}")
 string(REPLACE "@GIT_TEST_UTF8_LOCALE@" "" git_build_options "${git_build_options}")
@@ -1205,6 +1208,7 @@ string(REPLACE "@TEST_OUTPUT_DIRECTORY@" "" git_build_options "${git_build_optio
 string(REPLACE "@TEST_SHELL_PATH@" "'${TEST_SHELL_PATH}'" git_build_options "${git_build_options}")
 string(REPLACE "@USE_GETTEXT_SCHEME@" "" git_build_options "${git_build_options}")
 string(REPLACE "@USE_LIBPCRE2@" "" git_build_options "${git_build_options}")
+string(REPLACE "@WITH_BREAKING_CHANGES@" "" git_build_options "${git_build_options}")
 string(REPLACE "@X@" "${EXE_EXTENSION}" git_build_options "${git_build_options}")
 if(USE_VCPKG)
 	string(APPEND git_build_options "PATH=\"$PATH:$TEST_DIRECTORY/../compat/vcbuild/vcpkg/installed/x64-windows/bin\"\n")
diff --git a/contrib/coccinelle/meson.build b/contrib/coccinelle/meson.build
new file mode 100644
index 0000000000..ea054c924f
--- /dev/null
+++ b/contrib/coccinelle/meson.build
@@ -0,0 +1,94 @@
+coccinelle_opt = get_option('coccinelle').require(
+  fs.exists(meson.project_source_root() / '.git'),
+  error_message: 'coccinelle can only be run from a git checkout',
+)
+
+spatch = find_program('spatch', required: coccinelle_opt)
+if not spatch.found()
+  subdir_done()
+endif
+
+third_party_sources = [
+  ':!contrib',
+  ':!compat/inet_ntop.c',
+  ':!compat/inet_pton.c',
+  ':!compat/nedmalloc',
+  ':!compat/obstack.*',
+  ':!compat/poll',
+  ':!compat/regex',
+  ':!sha1collisiondetection',
+  ':!sha1dc',
+  ':!t/unit-tests/clar',
+  ':!t/unit-tests/clar',
+  ':!t/t[0-9][0-9][0-9][0-9]*',
+]
+
+rules = [
+  'array.cocci',
+  'commit.cocci',
+  'config_fn_ctx.pending.cocci',
+  'equals-null.cocci',
+  'flex_alloc.cocci',
+  'free.cocci',
+  'git_config_number.cocci',
+  'hashmap.cocci',
+  'index-compatibility.cocci',
+  'object_id.cocci',
+  'preincr.cocci',
+  'qsort.cocci',
+  'refs.cocci',
+  'strbuf.cocci',
+  'swap.cocci',
+  'the_repository.cocci',
+  'xcalloc.cocci',
+  'xopen.cocci',
+  'xstrdup_or_null.cocci',
+  'xstrncmpz.cocci',
+]
+
+concatenated_rules = custom_target(
+  command: [
+    'cat', '@INPUT@',
+  ],
+  input: rules,
+  output: 'rules.cocci',
+  capture: true,
+)
+
+sources = [ ]
+foreach source : run_command(git, '-C', meson.project_source_root(), 'ls-files', '--deduplicate', '*.c', third_party_sources, check: true).stdout().split()
+  sources += source
+endforeach
+
+headers = [ ]
+foreach header : run_command(git, '-C', meson.project_source_root(), 'ls-files', '--deduplicate', '*.h', third_party_sources, check: true).stdout().split()
+  headers += meson.project_source_root() / header
+endforeach
+
+patches = [ ]
+foreach source : sources
+  patches += custom_target(
+    command: [
+      spatch,
+      '--all-includes',
+      '--sp-file', concatenated_rules,
+      '--patch', meson.project_source_root(),
+      '@INPUT@',
+    ],
+    input: meson.project_source_root() / source,
+    output: source.underscorify() + '.patch',
+    capture: true,
+    depend_files: headers,
+  )
+endforeach
+
+concatenated_patch = custom_target(
+  command: [
+    'cat', '@INPUT@',
+  ],
+  input: patches,
+  output: 'cocci.patch',
+  capture: true,
+)
+
+alias_target('coccicheck', concatenated_patch)
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index b3b6aa3bae..e3d88b0672 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -234,6 +234,17 @@ __git_dequote ()
 	done
 }
 
+# Prints the number of slash-separated components in a path.
+# 1: Path to count components of.
+__git_count_path_components ()
+{
+	local path="$1"
+	local relative="${path#/}"
+	relative="${relative%/}"
+	local slashes="/${relative//[^\/]}"
+	echo "${#slashes}"
+}
+
 # The following function is based on code from:
 #
 #   bash_completion - programmable completion functions for bash 3.2+
@@ -779,16 +790,39 @@ __git_tags ()
 __git_dwim_remote_heads ()
 {
 	local pfx="${1-}" cur_="${2-}" sfx="${3-}"
-	local fer_pfx="${pfx//\%/%%}" # "escape" for-each-ref format specifiers
 
 	# employ the heuristic used by git checkout and git switch
 	# Try to find a remote branch that cur_es the completion word
 	# but only output if the branch name is unique
-	__git for-each-ref --format="$fer_pfx%(refname:strip=3)$sfx" \
-		--sort="refname:strip=3" \
-		${GIT_COMPLETION_IGNORE_CASE+--ignore-case} \
-		"refs/remotes/*/$cur_*" "refs/remotes/*/$cur_*/**" | \
-	uniq -u
+	local awk_script='
+	function casemap(s) {
+		if (ENVIRON["IGNORE_CASE"])
+			return tolower(s)
+		else
+			return s
+	}
+	BEGIN {
+		split(ENVIRON["REMOTES"], remotes, /\n/)
+		for (i in remotes)
+			remotes[i] = "refs/remotes/" casemap(remotes[i])
+		cur_ = casemap(ENVIRON["CUR_"])
+	}
+	{
+		ref_case = casemap($0)
+		for (i in remotes) {
+			if (index(ref_case, remotes[i] "/" cur_) == 1) {
+				branch = substr($0, length(remotes[i] "/") + 1)
+				print ENVIRON["PFX"] branch ENVIRON["SFX"]
+				break
+			}
+		}
+	}
+	'
+	__git for-each-ref --format='%(refname)' refs/remotes/ |
+		PFX="$pfx" SFX="$sfx" CUR_="$cur_" \
+			IGNORE_CASE=${GIT_COMPLETION_IGNORE_CASE+1} \
+			REMOTES="$(__git_remotes | sort -r)" awk "$awk_script" |
+		sort | uniq -u
 }
 
 # Lists refs from the local (by default) or from a remote repository.
@@ -894,7 +928,8 @@ __git_refs ()
 			case "HEAD" in
 			$match*|$umatch*)	echo "${pfx}HEAD$sfx" ;;
 			esac
-			__git for-each-ref --format="$fer_pfx%(refname:strip=3)$sfx" \
+			local strip="$(__git_count_path_components "refs/remotes/$remote")"
+			__git for-each-ref --format="$fer_pfx%(refname:strip=$strip)$sfx" \
 				${GIT_COMPLETION_IGNORE_CASE+--ignore-case} \
 				"refs/remotes/$remote/$match*" \
 				"refs/remotes/$remote/$match*/**"
@@ -2737,12 +2772,17 @@ __git_compute_config_vars_all ()
 	__git_config_vars_all="$(git --no-pager help --config)"
 }
 
+__git_indirect()
+{
+	eval printf '%s' "\"\$$1\""
+}
+
 __git_compute_first_level_config_vars_for_section ()
 {
 	local section="$1"
 	__git_compute_config_vars
 	local this_section="__git_first_level_config_vars_for_section_${section}"
-	test -n "${!this_section}" ||
+	test -n "$(__git_indirect "${this_section}")" ||
 	printf -v "__git_first_level_config_vars_for_section_${section}" %s \
 		"$(echo "$__git_config_vars" | awk -F. "/^${section}\.[a-z]/ { print \$2 }")"
 }
@@ -2752,7 +2792,7 @@ __git_compute_second_level_config_vars_for_section ()
 	local section="$1"
 	__git_compute_config_vars_all
 	local this_section="__git_second_level_config_vars_for_section_${section}"
-	test -n "${!this_section}" ||
+	test -n "$(__git_indirect "${this_section}")" ||
 	printf -v "__git_second_level_config_vars_for_section_${section}" %s \
 		"$(echo "$__git_config_vars_all" | awk -F. "/^${section}\.</ { print \$3 }")"
 }
@@ -2907,7 +2947,7 @@ __git_complete_config_variable_name ()
 		local section="${pfx%.*.}"
 		__git_compute_second_level_config_vars_for_section "${section}"
 		local this_section="__git_second_level_config_vars_for_section_${section}"
-		__gitcomp "${!this_section}" "$pfx" "$cur_" "$sfx"
+		__gitcomp "$(__git_indirect "${this_section}")" "$pfx" "$cur_" "$sfx"
 		return
 		;;
 	branch.*)
@@ -2917,7 +2957,7 @@ __git_complete_config_variable_name ()
 		__gitcomp_direct "$(__git_heads "$pfx" "$cur_" ".")"
 		__git_compute_first_level_config_vars_for_section "${section}"
 		local this_section="__git_first_level_config_vars_for_section_${section}"
-		__gitcomp_nl_append "${!this_section}" "$pfx" "$cur_" "${sfx:- }"
+		__gitcomp_nl_append "$(__git_indirect "${this_section}")" "$pfx" "$cur_" "${sfx:- }"
 		return
 		;;
 	pager.*)
@@ -2934,7 +2974,7 @@ __git_complete_config_variable_name ()
 		__gitcomp_nl "$(__git_remotes)" "$pfx" "$cur_" "."
 		__git_compute_first_level_config_vars_for_section "${section}"
 		local this_section="__git_first_level_config_vars_for_section_${section}"
-		__gitcomp_nl_append "${!this_section}" "$pfx" "$cur_" "${sfx:- }"
+		__gitcomp_nl_append "$(__git_indirect "${this_section}")" "$pfx" "$cur_" "${sfx:- }"
 		return
 		;;
 	submodule.*)
@@ -2944,7 +2984,7 @@ __git_complete_config_variable_name ()
 		__gitcomp_nl "$(__git config -f "$(__git rev-parse --show-toplevel)/.gitmodules" --get-regexp 'submodule.*.path' | awk -F. '{print $2}')" "$pfx" "$cur_" "."
 		__git_compute_first_level_config_vars_for_section "${section}"
 		local this_section="__git_first_level_config_vars_for_section_${section}"
-		__gitcomp_nl_append "${!this_section}" "$pfx" "$cur_" "${sfx:- }"
+		__gitcomp_nl_append "$(__git_indirect "${this_section}")" "$pfx" "$cur_" "${sfx:- }"
 		return
 		;;
 	*.*)
diff --git a/contrib/contacts/Makefile b/contrib/contacts/Makefile
index a2990f0dcb..9c4ca4f3bc 100644
--- a/contrib/contacts/Makefile
+++ b/contrib/contacts/Makefile
@@ -34,7 +34,7 @@ GIT_CONTACTS := git-contacts
 
 GIT_CONTACTS_DOC := git-contacts.1
 GIT_CONTACTS_XML := git-contacts.xml
-GIT_CONTACTS_TXT := git-contacts.txt
+GIT_CONTACTS_TXT := git-contacts.adoc
 GIT_CONTACTS_HTML := git-contacts.html
 
 doc: $(GIT_CONTACTS_DOC) $(GIT_CONTACTS_HTML)
diff --git a/contrib/contacts/git-contacts.txt b/contrib/contacts/git-contacts.adoc
index dd914d1261..dd914d1261 100644
--- a/contrib/contacts/git-contacts.txt
+++ b/contrib/contacts/git-contacts.adoc
diff --git a/contrib/contacts/meson.build b/contrib/contacts/meson.build
new file mode 100644
index 0000000000..73d82dfe52
--- /dev/null
+++ b/contrib/contacts/meson.build
@@ -0,0 +1,55 @@
+custom_target(
+  input: 'git-contacts',
+  output: 'git-contacts',
+  command: generate_perl_command,
+  depends: [git_version_file],
+  install: true,
+  install_dir: get_option('libexecdir') / 'git-core',
+)
+
+if get_option('docs').contains('man')
+  contacts_xml = custom_target(
+    command: asciidoc_common_options + [
+      '--backend=' + asciidoc_docbook,
+      '--doctype=manpage',
+      '--out-file=@OUTPUT@',
+      '@INPUT@',
+    ],
+    depends: documentation_deps,
+    input: 'git-contacts.adoc',
+    output: 'git-contacts.xml',
+  )
+
+  custom_target(
+    command: [
+      xmlto,
+      '-m', '@INPUT@',
+      'man',
+      contacts_xml,
+      '-o',
+      meson.current_build_dir(),
+    ] + xmlto_extra,
+    input: [
+      '../../Documentation/manpage-normal.xsl',
+    ],
+    output: 'git-contacts.1',
+    install: true,
+    install_dir: get_option('mandir') / 'man1',
+  )
+endif
+
+if get_option('docs').contains('html')
+  custom_target(
+    command: asciidoc_common_options + [
+      '--backend=' + asciidoc_html,
+      '--doctype=manpage',
+      '--out-file=@OUTPUT@',
+      '@INPUT@',
+    ],
+    depends: documentation_deps,
+    input: 'git-contacts.adoc',
+    output: 'git-contacts.html',
+    install: true,
+    install_dir: get_option('datadir') / 'doc/git-doc',
+  )
+endif
diff --git a/contrib/credential/libsecret/Makefile b/contrib/credential/libsecret/Makefile
index 3e67552cc5..97ce9c92fb 100644
--- a/contrib/credential/libsecret/Makefile
+++ b/contrib/credential/libsecret/Makefile
@@ -1,3 +1,6 @@
+# The default target of this Makefile is...
+all::
+
 MAIN:=git-credential-libsecret
 all:: $(MAIN)
 
diff --git a/contrib/credential/libsecret/git-credential-libsecret.c b/contrib/credential/libsecret/git-credential-libsecret.c
index 90034d0cf1..941b2afd5e 100644
--- a/contrib/credential/libsecret/git-credential-libsecret.c
+++ b/contrib/credential/libsecret/git-credential-libsecret.c
@@ -59,10 +59,10 @@ static void credential_clear(struct credential *c);
 /* ----------------- Secret Service functions ----------------- */
 
 static const SecretSchema schema = {
-	"org.git.Password",
+	.name = "org.git.Password",
 	/* Ignore schema name during search for backwards compatibility */
-	SECRET_SCHEMA_DONT_MATCH_NAME,
-	{
+	.flags = SECRET_SCHEMA_DONT_MATCH_NAME,
+	.attributes = {
 		/*
 		 * libsecret assumes attribute values are non-confidential and
 		 * unchanging, so we can't include oauth_refresh_token or
@@ -168,7 +168,7 @@ static int keyring_get(struct credential *c)
 				g_free(c->password);
 				c->password = g_strdup("");
 			}
-			for (int i = 1; i < g_strv_length(parts); i++) {
+			for (guint i = 1; i < g_strv_length(parts); i++) {
 				if (g_str_has_prefix(parts[i], "password_expiry_utc=")) {
 					g_free(c->password_expiry_utc);
 					c->password_expiry_utc = g_strdup(&parts[i][20]);
@@ -424,7 +424,7 @@ int main(int argc, char *argv[])
 	struct credential_operation const *try_op = credential_helper_ops;
 	struct credential cred = CREDENTIAL_INIT;
 
-	if (!argv[1]) {
+	if (argc < 2 || !*argv[1]) {
 		usage(argv[0]);
 		exit(EXIT_FAILURE);
 	}
diff --git a/contrib/credential/libsecret/meson.build b/contrib/credential/libsecret/meson.build
new file mode 100644
index 0000000000..0137660fe0
--- /dev/null
+++ b/contrib/credential/libsecret/meson.build
@@ -0,0 +1,9 @@
+executable('git-credential-libsecret',
+  sources: 'git-credential-libsecret.c',
+  dependencies: [
+    dependency('glib-2.0'),
+    dependency('libsecret-1'),
+  ],
+  install: true,
+  install_dir: get_option('libexecdir') / 'git-core',
+)
diff --git a/contrib/credential/meson.build b/contrib/credential/meson.build
new file mode 100644
index 0000000000..4216296ae0
--- /dev/null
+++ b/contrib/credential/meson.build
@@ -0,0 +1,3 @@
+foreach helper : get_option('credential_helpers')
+  subdir(helper)
+endforeach
diff --git a/contrib/credential/netrc/meson.build b/contrib/credential/netrc/meson.build
new file mode 100644
index 0000000000..3d74547c8a
--- /dev/null
+++ b/contrib/credential/netrc/meson.build
@@ -0,0 +1,22 @@
+credential_netrc = custom_target(
+  input: 'git-credential-netrc.perl',
+  output: 'git-credential-netrc',
+  command: generate_perl_command,
+  depends: [git_version_file],
+  install: true,
+  install_dir: get_option('libexecdir') / 'git-core',
+)
+
+if get_option('tests')
+  credential_netrc_testenv = test_environment
+  credential_netrc_testenv.set('CREDENTIAL_NETRC_PATH', credential_netrc.full_path())
+
+  test('t-git-credential-netrc',
+    shell,
+    args: [ meson.current_source_dir() / 't-git-credential-netrc.sh' ],
+    workdir: meson.current_source_dir(),
+    env: credential_netrc_testenv,
+    depends: test_dependencies + bin_wrappers + [credential_netrc],
+    timeout: 0,
+  )
+endif
diff --git a/contrib/credential/netrc/t-git-credential-netrc.sh b/contrib/credential/netrc/t-git-credential-netrc.sh
index bf2777308a..1b7b8b3a9a 100755
--- a/contrib/credential/netrc/t-git-credential-netrc.sh
+++ b/contrib/credential/netrc/t-git-credential-netrc.sh
@@ -15,7 +15,7 @@
 
 	export PERL5LIB="$GITPERLLIB"
 	test_expect_success 'git-credential-netrc' '
-		perl "$GIT_BUILD_DIR"/contrib/credential/netrc/test.pl
+		perl "$GIT_SOURCE_DIR"/contrib/credential/netrc/test.pl
 	'
 
 	test_done
diff --git a/contrib/credential/netrc/test.pl b/contrib/credential/netrc/test.pl
index c0fb3718b2..67a0ede564 100755
--- a/contrib/credential/netrc/test.pl
+++ b/contrib/credential/netrc/test.pl
@@ -15,10 +15,11 @@ BEGIN {
 
 my @global_credential_args = @ARGV;
 my $scriptDir = dirname rel2abs $0;
-my ($netrc, $netrcGpg, $gcNetrc) = map { catfile $scriptDir, $_; }
+my ($netrc, $netrcGpg) = map { catfile $scriptDir, $_; }
                                        qw(test.netrc
-                                          test.netrc.gpg
-                                          git-credential-netrc);
+                                          test.netrc.gpg);
+my $gcNetrc = $ENV{CREDENTIAL_NETRC_PATH} || catfile $scriptDir, qw(git-credential-netrc);
+
 local $ENV{PATH} = join ':'
                       , $scriptDir
                       , $ENV{PATH}
diff --git a/contrib/credential/osxkeychain/Makefile b/contrib/credential/osxkeychain/Makefile
index 238f5f8c36..0948297e20 100644
--- a/contrib/credential/osxkeychain/Makefile
+++ b/contrib/credential/osxkeychain/Makefile
@@ -1,3 +1,4 @@
+# The default target of this Makefile is...
 all:: git-credential-osxkeychain
 
 CC = gcc
diff --git a/contrib/credential/osxkeychain/git-credential-osxkeychain.c b/contrib/credential/osxkeychain/git-credential-osxkeychain.c
index 1c8310d7fe..611c9798b3 100644
--- a/contrib/credential/osxkeychain/git-credential-osxkeychain.c
+++ b/contrib/credential/osxkeychain/git-credential-osxkeychain.c
@@ -422,7 +422,7 @@ int main(int argc, const char **argv)
 	const char *usage =
 		"usage: git credential-osxkeychain <get|store|erase>";
 
-	if (!argv[1])
+	if (argc < 2 || !*argv[1])
 		die("%s", usage);
 
 	if (open(argv[0], O_RDONLY | O_EXLOCK) == -1)
diff --git a/contrib/credential/osxkeychain/meson.build b/contrib/credential/osxkeychain/meson.build
new file mode 100644
index 0000000000..3c7677f736
--- /dev/null
+++ b/contrib/credential/osxkeychain/meson.build
@@ -0,0 +1,9 @@
+executable('git-credential-osxkeychain',
+  sources: 'git-credential-osxkeychain.c',
+  dependencies: [
+    dependency('CoreFoundation'),
+    dependency('Security'),
+  ],
+  install: true,
+  install_dir: get_option('libexecdir') / 'git-core',
+)
diff --git a/contrib/credential/wincred/Makefile b/contrib/credential/wincred/Makefile
index 6e992c0866..5b795fc9fe 100644
--- a/contrib/credential/wincred/Makefile
+++ b/contrib/credential/wincred/Makefile
@@ -1,4 +1,5 @@
-all: git-credential-wincred.exe
+# The default target of this Makefile is...
+all:: git-credential-wincred.exe
 
 -include ../../../config.mak.autogen
 -include ../../../config.mak
diff --git a/contrib/credential/wincred/git-credential-wincred.c b/contrib/credential/wincred/git-credential-wincred.c
index 4be0d58cd8..04145b5118 100644
--- a/contrib/credential/wincred/git-credential-wincred.c
+++ b/contrib/credential/wincred/git-credential-wincred.c
@@ -12,7 +12,9 @@
 
 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
 
+#ifndef _MSC_VER
 __attribute__((format (printf, 1, 2)))
+#endif
 static void die(const char *err, ...)
 {
 	char msg[4096];
diff --git a/contrib/credential/wincred/meson.build b/contrib/credential/wincred/meson.build
new file mode 100644
index 0000000000..6de23ca17d
--- /dev/null
+++ b/contrib/credential/wincred/meson.build
@@ -0,0 +1,5 @@
+executable('git-credential-wincred',
+  sources: 'git-credential-wincred.c',
+  install: true,
+  install_dir: get_option('libexecdir') / 'git-core',
+)
diff --git a/contrib/diff-highlight/Makefile b/contrib/diff-highlight/Makefile
index f2be7cc924..33c2ccc9f7 100644
--- a/contrib/diff-highlight/Makefile
+++ b/contrib/diff-highlight/Makefile
@@ -1,4 +1,5 @@
-all: diff-highlight
+# The default target of this Makefile is...
+all:: diff-highlight
 
 PERL_PATH = /usr/bin/perl
 -include ../../config.mak
diff --git a/contrib/diff-highlight/t/Makefile b/contrib/diff-highlight/t/Makefile
index 5ff5275496..2a98541477 100644
--- a/contrib/diff-highlight/t/Makefile
+++ b/contrib/diff-highlight/t/Makefile
@@ -1,3 +1,6 @@
+# The default target of this Makefile is...
+all::
+
 -include ../../../config.mak.autogen
 -include ../../../config.mak
 
@@ -6,7 +9,7 @@ SHELL_PATH ?= $(SHELL)
 SHELL_PATH_SQ = $(subst ','\'',$(SHELL_PATH))
 T = $(wildcard t[0-9][0-9][0-9][0-9]-*.sh)
 
-all: test
+all:: test
 test: $(T)
 
 .PHONY: help clean all test $(T)
diff --git a/contrib/libgit-rs/Cargo.lock b/contrib/libgit-rs/Cargo.lock
new file mode 100644
index 0000000000..a30c7c8d33
--- /dev/null
+++ b/contrib/libgit-rs/Cargo.lock
@@ -0,0 +1,77 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "autocfg"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ace50bade8e6234aa140d9a2f552bbee1db4d353f69b8217bc503490fc1a9f26"
+
+[[package]]
+name = "cc"
+version = "1.1.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57b6a275aa2903740dc87da01c62040406b8812552e97129a63ea8850a17c6e6"
+dependencies = [
+ "shlex",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.158"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d8adc4bb1803a324070e64a98ae98f38934d91957a99cfb3a43dcbc01bc56439"
+
+[[package]]
+name = "libgit"
+version = "0.1.0"
+dependencies = [
+ "autocfg",
+ "libgit-sys",
+]
+
+[[package]]
+name = "libgit-sys"
+version = "0.1.0"
+dependencies = [
+ "autocfg",
+ "libz-sys",
+ "make-cmd",
+]
+
+[[package]]
+name = "libz-sys"
+version = "1.1.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d2d16453e800a8cf6dd2fc3eb4bc99b786a9b90c663b8559a5b1a041bf89e472"
+dependencies = [
+ "cc",
+ "libc",
+ "pkg-config",
+ "vcpkg",
+]
+
+[[package]]
+name = "make-cmd"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a8ca8afbe8af1785e09636acb5a41e08a765f5f0340568716c18a8700ba3c0d3"
+
+[[package]]
+name = "pkg-config"
+version = "0.3.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d231b230927b5e4ad203db57bbcbee2802f6bce620b1e4a9024a07d94e2907ec"
+
+[[package]]
+name = "shlex"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
+
+[[package]]
+name = "vcpkg"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "accd4ea62f7bb7a82fe23066fb0957d48ef677f6eeb8215f372f52e48bb32426"
diff --git a/contrib/libgit-rs/Cargo.toml b/contrib/libgit-rs/Cargo.toml
new file mode 100644
index 0000000000..c3289e69db
--- /dev/null
+++ b/contrib/libgit-rs/Cargo.toml
@@ -0,0 +1,17 @@
+[package]
+name = "libgit"
+version = "0.1.0"
+edition = "2021"
+build = "build.rs"
+rust-version = "1.63" # TODO: Once we hit 1.84 or newer, we may want to remove Cargo.lock from
+                      # version control. See https://lore.kernel.org/git/Z47jgK-oMjFRSslr@tapette.crustytoothpaste.net/
+
+
+[lib]
+path = "src/lib.rs"
+
+[dependencies]
+libgit-sys = { version = "0.1.0", path = "../libgit-sys" }
+
+[build-dependencies]
+autocfg = "1.4.0"
diff --git a/contrib/libgit-rs/README.md b/contrib/libgit-rs/README.md
new file mode 100644
index 0000000000..ff945e1ce2
--- /dev/null
+++ b/contrib/libgit-rs/README.md
@@ -0,0 +1,13 @@
+# libgit-rs
+
+Proof-of-concept Git bindings for Rust.
+
+```toml
+[dependencies]
+libgit = "0.1.0"
+```
+
+## Rust version requirements
+
+libgit-rs should support Rust versions at least as old as the version included
+in Debian stable (currently 1.63).
diff --git a/contrib/libgit-rs/build.rs b/contrib/libgit-rs/build.rs
new file mode 100644
index 0000000000..f8bd01a690
--- /dev/null
+++ b/contrib/libgit-rs/build.rs
@@ -0,0 +1,4 @@
+pub fn main() {
+    let ac = autocfg::new();
+    ac.emit_has_path("std::ffi::c_char");
+}
diff --git a/contrib/libgit-rs/src/config.rs b/contrib/libgit-rs/src/config.rs
new file mode 100644
index 0000000000..6bf04845c8
--- /dev/null
+++ b/contrib/libgit-rs/src/config.rs
@@ -0,0 +1,106 @@
+use std::ffi::{c_void, CStr, CString};
+use std::path::Path;
+
+#[cfg(has_std__ffi__c_char)]
+use std::ffi::{c_char, c_int};
+
+#[cfg(not(has_std__ffi__c_char))]
+#[allow(non_camel_case_types)]
+type c_char = i8;
+
+#[cfg(not(has_std__ffi__c_char))]
+#[allow(non_camel_case_types)]
+type c_int = i32;
+
+use libgit_sys::*;
+
+/// A ConfigSet is an in-memory cache for config-like files such as `.gitmodules` or `.gitconfig`.
+/// It does not support all config directives; notably, it will not process `include` or
+/// `includeIf` directives (but it will store them so that callers can choose whether and how to
+/// handle them).
+pub struct ConfigSet(*mut libgit_config_set);
+impl ConfigSet {
+    /// Allocate a new ConfigSet
+    pub fn new() -> Self {
+        unsafe { ConfigSet(libgit_configset_alloc()) }
+    }
+
+    /// Load the given files into the ConfigSet; conflicting directives in later files will
+    /// override those given in earlier files.
+    pub fn add_files(&mut self, files: &[&Path]) {
+        for file in files {
+            let pstr = file.to_str().expect("Invalid UTF-8");
+            let rs = CString::new(pstr).expect("Couldn't convert to CString");
+            unsafe {
+                libgit_configset_add_file(self.0, rs.as_ptr());
+            }
+        }
+    }
+
+    /// Load the value for the given key and attempt to parse it as an i32. Dies with a fatal error
+    /// if the value cannot be parsed. Returns None if the key is not present.
+    pub fn get_int(&mut self, key: &str) -> Option<i32> {
+        let key = CString::new(key).expect("Couldn't convert to CString");
+        let mut val: c_int = 0;
+        unsafe {
+            if libgit_configset_get_int(self.0, key.as_ptr(), &mut val as *mut c_int) != 0 {
+                return None;
+            }
+        }
+
+        Some(val.into())
+    }
+
+    /// Clones the value for the given key. Dies with a fatal error if the value cannot be
+    /// converted to a String. Returns None if the key is not present.
+    pub fn get_string(&mut self, key: &str) -> Option<String> {
+        let key = CString::new(key).expect("Couldn't convert key to CString");
+        let mut val: *mut c_char = std::ptr::null_mut();
+        unsafe {
+            if libgit_configset_get_string(self.0, key.as_ptr(), &mut val as *mut *mut c_char) != 0
+            {
+                return None;
+            }
+            let borrowed_str = CStr::from_ptr(val);
+            let owned_str =
+                String::from(borrowed_str.to_str().expect("Couldn't convert val to str"));
+            free(val as *mut c_void); // Free the xstrdup()ed pointer from the C side
+            Some(owned_str)
+        }
+    }
+}
+
+impl Default for ConfigSet {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl Drop for ConfigSet {
+    fn drop(&mut self) {
+        unsafe {
+            libgit_configset_free(self.0);
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn load_configs_via_configset() {
+        let mut cs = ConfigSet::new();
+        cs.add_files(&[
+            Path::new("testdata/config1"),
+            Path::new("testdata/config2"),
+            Path::new("testdata/config3"),
+        ]);
+        // ConfigSet retrieves correct value
+        assert_eq!(cs.get_int("trace2.eventTarget"), Some(1));
+        // ConfigSet respects last config value set
+        assert_eq!(cs.get_int("trace2.eventNesting"), Some(3));
+        // ConfigSet returns None for missing key
+        assert_eq!(cs.get_string("foo.bar"), None);
+    }
+}
diff --git a/contrib/libgit-rs/src/lib.rs b/contrib/libgit-rs/src/lib.rs
new file mode 100644
index 0000000000..ef68c36943
--- /dev/null
+++ b/contrib/libgit-rs/src/lib.rs
@@ -0,0 +1 @@
+pub mod config;
diff --git a/contrib/libgit-rs/testdata/config1 b/contrib/libgit-rs/testdata/config1
new file mode 100644
index 0000000000..4e9a9d25d1
--- /dev/null
+++ b/contrib/libgit-rs/testdata/config1
@@ -0,0 +1,2 @@
+[trace2]
+	eventNesting = 1
diff --git a/contrib/libgit-rs/testdata/config2 b/contrib/libgit-rs/testdata/config2
new file mode 100644
index 0000000000..b8d1eca423
--- /dev/null
+++ b/contrib/libgit-rs/testdata/config2
@@ -0,0 +1,2 @@
+[trace2]
+	eventTarget = 1
diff --git a/contrib/libgit-rs/testdata/config3 b/contrib/libgit-rs/testdata/config3
new file mode 100644
index 0000000000..ca7b9a7c38
--- /dev/null
+++ b/contrib/libgit-rs/testdata/config3
@@ -0,0 +1,2 @@
+[trace2]
+	eventNesting = 3
diff --git a/contrib/libgit-sys/Cargo.lock b/contrib/libgit-sys/Cargo.lock
new file mode 100644
index 0000000000..427a4c66b7
--- /dev/null
+++ b/contrib/libgit-sys/Cargo.lock
@@ -0,0 +1,69 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "autocfg"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ace50bade8e6234aa140d9a2f552bbee1db4d353f69b8217bc503490fc1a9f26"
+
+[[package]]
+name = "cc"
+version = "1.1.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57b6a275aa2903740dc87da01c62040406b8812552e97129a63ea8850a17c6e6"
+dependencies = [
+ "shlex",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.158"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d8adc4bb1803a324070e64a98ae98f38934d91957a99cfb3a43dcbc01bc56439"
+
+[[package]]
+name = "libgit-sys"
+version = "0.1.0"
+dependencies = [
+ "autocfg",
+ "libz-sys",
+ "make-cmd",
+]
+
+[[package]]
+name = "libz-sys"
+version = "1.1.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d2d16453e800a8cf6dd2fc3eb4bc99b786a9b90c663b8559a5b1a041bf89e472"
+dependencies = [
+ "cc",
+ "libc",
+ "pkg-config",
+ "vcpkg",
+]
+
+[[package]]
+name = "make-cmd"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a8ca8afbe8af1785e09636acb5a41e08a765f5f0340568716c18a8700ba3c0d3"
+
+[[package]]
+name = "pkg-config"
+version = "0.3.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d231b230927b5e4ad203db57bbcbee2802f6bce620b1e4a9024a07d94e2907ec"
+
+[[package]]
+name = "shlex"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
+
+[[package]]
+name = "vcpkg"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "accd4ea62f7bb7a82fe23066fb0957d48ef677f6eeb8215f372f52e48bb32426"
diff --git a/contrib/libgit-sys/Cargo.toml b/contrib/libgit-sys/Cargo.toml
new file mode 100644
index 0000000000..e0623022c3
--- /dev/null
+++ b/contrib/libgit-sys/Cargo.toml
@@ -0,0 +1,19 @@
+[package]
+name = "libgit-sys"
+version = "0.1.0"
+edition = "2021"
+build = "build.rs"
+links = "gitpub"
+rust-version = "1.63" # TODO: Once we hit 1.84 or newer, we may want to remove Cargo.lock from
+                      # version control. See https://lore.kernel.org/git/Z47jgK-oMjFRSslr@tapette.crustytoothpaste.net/
+description = "Native bindings to a portion of libgit"
+
+[lib]
+path = "src/lib.rs"
+
+[dependencies]
+libz-sys = "1.1.19"
+
+[build-dependencies]
+autocfg = "1.4.0"
+make-cmd = "0.1.0"
diff --git a/contrib/libgit-sys/README.md b/contrib/libgit-sys/README.md
new file mode 100644
index 0000000000..c061cfcaf5
--- /dev/null
+++ b/contrib/libgit-sys/README.md
@@ -0,0 +1,4 @@
+# libgit-sys
+
+A small proof-of-concept crate showing how to provide a Rust FFI to Git
+internals.
diff --git a/contrib/libgit-sys/build.rs b/contrib/libgit-sys/build.rs
new file mode 100644
index 0000000000..3ffd80ad91
--- /dev/null
+++ b/contrib/libgit-sys/build.rs
@@ -0,0 +1,35 @@
+use std::env;
+use std::path::PathBuf;
+
+pub fn main() -> std::io::Result<()> {
+    let ac = autocfg::new();
+    ac.emit_has_path("std::ffi::c_char");
+
+    let crate_root = PathBuf::from(env::var_os("CARGO_MANIFEST_DIR").unwrap());
+    let git_root = crate_root.join("../..");
+    let dst = PathBuf::from(env::var_os("OUT_DIR").unwrap());
+
+    let make_output = make_cmd::gnu_make()
+        .env("DEVELOPER", "1")
+        .env_remove("PROFILE")
+        .current_dir(git_root.clone())
+        .args([
+            "INCLUDE_LIBGIT_RS=YesPlease",
+            "contrib/libgit-sys/libgitpub.a",
+        ])
+        .output()
+        .expect("Make failed to run");
+    if !make_output.status.success() {
+        panic!(
+            "Make failed:\n  stdout = {}\n  stderr = {}\n",
+            String::from_utf8(make_output.stdout).unwrap(),
+            String::from_utf8(make_output.stderr).unwrap()
+        );
+    }
+    std::fs::copy(crate_root.join("libgitpub.a"), dst.join("libgitpub.a"))?;
+    println!("cargo:rustc-link-search=native={}", dst.display());
+    println!("cargo:rustc-link-lib=gitpub");
+    println!("cargo:rerun-if-changed={}", git_root.display());
+
+    Ok(())
+}
diff --git a/contrib/libgit-sys/public_symbol_export.c b/contrib/libgit-sys/public_symbol_export.c
new file mode 100644
index 0000000000..dfbb257115
--- /dev/null
+++ b/contrib/libgit-sys/public_symbol_export.c
@@ -0,0 +1,59 @@
+/*
+ * Shim to publicly export Git symbols. These must be renamed so that the
+ * original symbols can be hidden. Renaming these with a "libgit_" prefix also
+ * avoids conflicts with other libraries such as libgit2.
+ */
+
+#include "git-compat-util.h"
+#include "config.h"
+#include "contrib/libgit-sys/public_symbol_export.h"
+#include "version.h"
+
+#pragma GCC visibility push(default)
+
+struct libgit_config_set {
+	struct config_set cs;
+};
+
+struct libgit_config_set *libgit_configset_alloc(void)
+{
+	struct libgit_config_set *cs =
+			xmalloc(sizeof(struct libgit_config_set));
+	git_configset_init(&cs->cs);
+	return cs;
+}
+
+void libgit_configset_free(struct libgit_config_set *cs)
+{
+	git_configset_clear(&cs->cs);
+	free(cs);
+}
+
+int libgit_configset_add_file(struct libgit_config_set *cs, const char *filename)
+{
+	return git_configset_add_file(&cs->cs, filename);
+}
+
+int libgit_configset_get_int(struct libgit_config_set *cs, const char *key,
+			     int *dest)
+{
+	return git_configset_get_int(&cs->cs, key, dest);
+}
+
+int libgit_configset_get_string(struct libgit_config_set *cs, const char *key,
+				char **dest)
+{
+	return git_configset_get_string(&cs->cs, key, dest);
+}
+
+const char *libgit_user_agent(void)
+{
+	return git_user_agent();
+}
+
+const char *libgit_user_agent_sanitized(void)
+{
+	return git_user_agent_sanitized();
+}
+
+#pragma GCC visibility pop
diff --git a/contrib/libgit-sys/public_symbol_export.h b/contrib/libgit-sys/public_symbol_export.h
new file mode 100644
index 0000000000..701db92d53
--- /dev/null
+++ b/contrib/libgit-sys/public_symbol_export.h
@@ -0,0 +1,18 @@
+#ifndef PUBLIC_SYMBOL_EXPORT_H
+#define PUBLIC_SYMBOL_EXPORT_H
+
+struct libgit_config_set *libgit_configset_alloc(void);
+
+void libgit_configset_free(struct libgit_config_set *cs);
+
+int libgit_configset_add_file(struct libgit_config_set *cs, const char *filename);
+
+int libgit_configset_get_int(struct libgit_config_set *cs, const char *key, int *dest);
+
+int libgit_configset_get_string(struct libgit_config_set *cs, const char *key, char **dest);
+
+const char *libgit_user_agent(void);
+
+const char *libgit_user_agent_sanitized(void);
+
+#endif /* PUBLIC_SYMBOL_EXPORT_H */
diff --git a/contrib/libgit-sys/src/lib.rs b/contrib/libgit-sys/src/lib.rs
new file mode 100644
index 0000000000..4bfc650450
--- /dev/null
+++ b/contrib/libgit-sys/src/lib.rs
@@ -0,0 +1,79 @@
+use std::ffi::c_void;
+
+#[cfg(has_std__ffi__c_char)]
+use std::ffi::{c_char, c_int};
+
+#[cfg(not(has_std__ffi__c_char))]
+#[allow(non_camel_case_types)]
+pub type c_char = i8;
+
+#[cfg(not(has_std__ffi__c_char))]
+#[allow(non_camel_case_types)]
+pub type c_int = i32;
+
+extern crate libz_sys;
+
+#[allow(non_camel_case_types)]
+#[repr(C)]
+pub struct libgit_config_set {
+    _data: [u8; 0],
+    _marker: core::marker::PhantomData<(*mut u8, core::marker::PhantomPinned)>,
+}
+
+extern "C" {
+    pub fn free(ptr: *mut c_void);
+
+    pub fn libgit_user_agent() -> *const c_char;
+    pub fn libgit_user_agent_sanitized() -> *const c_char;
+
+    pub fn libgit_configset_alloc() -> *mut libgit_config_set;
+    pub fn libgit_configset_free(cs: *mut libgit_config_set);
+
+    pub fn libgit_configset_add_file(cs: *mut libgit_config_set, filename: *const c_char) -> c_int;
+
+    pub fn libgit_configset_get_int(
+        cs: *mut libgit_config_set,
+        key: *const c_char,
+        int: *mut c_int,
+    ) -> c_int;
+
+    pub fn libgit_configset_get_string(
+        cs: *mut libgit_config_set,
+        key: *const c_char,
+        dest: *mut *mut c_char,
+    ) -> c_int;
+
+}
+
+#[cfg(test)]
+mod tests {
+    use std::ffi::CStr;
+
+    use super::*;
+
+    #[test]
+    fn user_agent_starts_with_git() {
+        let c_str = unsafe { CStr::from_ptr(libgit_user_agent()) };
+        let agent = c_str
+            .to_str()
+            .expect("User agent contains invalid UTF-8 data");
+        assert!(
+            agent.starts_with("git/"),
+            r#"Expected user agent to start with "git/", got: {}"#,
+            agent
+        );
+    }
+
+    #[test]
+    fn sanitized_user_agent_starts_with_git() {
+        let c_str = unsafe { CStr::from_ptr(libgit_user_agent_sanitized()) };
+        let agent = c_str
+            .to_str()
+            .expect("Sanitized user agent contains invalid UTF-8 data");
+        assert!(
+            agent.starts_with("git/"),
+            r#"Expected user agent to start with "git/", got: {}"#,
+            agent
+        );
+    }
+}
diff --git a/contrib/long-running-filter/example.pl b/contrib/long-running-filter/example.pl
index a677569ddd..4b83e4c5e8 100755
--- a/contrib/long-running-filter/example.pl
+++ b/contrib/long-running-filter/example.pl
@@ -1,7 +1,7 @@
 #!/usr/bin/perl
 #
 # Example implementation for the Git filter protocol version 2
-# See Documentation/gitattributes.txt, section "Filter Protocol"
+# See Documentation/gitattributes.adoc, section "Filter Protocol"
 #
 # Please note, this pass-thru filter is a minimal skeleton. No proper
 # error handling was implemented.
diff --git a/contrib/meson.build b/contrib/meson.build
index a7b77b87c2..a88c5dfe09 100644
--- a/contrib/meson.build
+++ b/contrib/meson.build
@@ -1 +1,6 @@
-subdir('completion')
+foreach feature : get_option('contrib')
+  subdir(feature)
+endforeach
+
+subdir('coccinelle')
+subdir('credential')
diff --git a/contrib/mw-to-git/Makefile b/contrib/mw-to-git/Makefile
index 4e603512a3..497ac434d6 100644
--- a/contrib/mw-to-git/Makefile
+++ b/contrib/mw-to-git/Makefile
@@ -12,6 +12,9 @@
 #
 #   make install
 
+# The default target of this Makefile is...
+all::
+
 GIT_MEDIAWIKI_PM=Git/Mediawiki.pm
 SCRIPT_PERL=git-remote-mediawiki.perl
 SCRIPT_PERL+=git-mw.perl
@@ -27,7 +30,7 @@ INSTLIBDIR=$(shell $(MAKE) -C $(GIT_ROOT_DIR)/ \
 DESTDIR_SQ = $(subst ','\'',$(DESTDIR))
 INSTLIBDIR_SQ = $(subst ','\'',$(INSTLIBDIR))
 
-all: build
+all:: build
 
 test: all
 	$(MAKE) -C t
diff --git a/contrib/mw-to-git/t/Makefile b/contrib/mw-to-git/t/Makefile
index f422203fa0..6c9f377caa 100644
--- a/contrib/mw-to-git/t/Makefile
+++ b/contrib/mw-to-git/t/Makefile
@@ -8,7 +8,8 @@
 #
 ## Test git-remote-mediawiki
 
-all: test
+# The default target of this Makefile is...
+all:: test
 
 -include ../../../config.mak.autogen
 -include ../../../config.mak
diff --git a/contrib/persistent-https/Makefile b/contrib/persistent-https/Makefile
index 52b84ba3d4..691737e76b 100644
--- a/contrib/persistent-https/Makefile
+++ b/contrib/persistent-https/Makefile
@@ -12,10 +12,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+# The default target of this Makefile is...
+all::
+
 BUILD_LABEL=$(shell cut -d" " -f3 ../../GIT-VERSION-FILE)
 TAR_OUT=$(shell go env GOOS)_$(shell go env GOARCH).tar.gz
 
-all: git-remote-persistent-https git-remote-persistent-https--proxy \
+all:: git-remote-persistent-https git-remote-persistent-https--proxy \
 	git-remote-persistent-http
 
 git-remote-persistent-https--proxy: git-remote-persistent-https
diff --git a/contrib/subtree/.gitignore b/contrib/subtree/.gitignore
index 0b9381abca..6deaf177c7 100644
--- a/contrib/subtree/.gitignore
+++ b/contrib/subtree/.gitignore
@@ -1,4 +1,6 @@
 *~
+asciidoc.conf
+asciidoctor-extensions.rb
 git-subtree
 git-subtree.1
 git-subtree.html
diff --git a/contrib/subtree/Makefile b/contrib/subtree/Makefile
index 6fa7496bfd..c0c9f21cb7 100644
--- a/contrib/subtree/Makefile
+++ b/contrib/subtree/Makefile
@@ -1,6 +1,7 @@
 # The default target of this Makefile is...
 all::
 
+-include ../../shared.mak
 -include ../../config.mak.autogen
 -include ../../config.mak
 
@@ -13,17 +14,16 @@ htmldir ?= $(prefix)/share/doc/git-doc
 ../../GIT-VERSION-FILE: FORCE
 	$(MAKE) -C ../../ GIT-VERSION-FILE
 
--include ../../GIT-VERSION-FILE
-
 # this should be set to a 'standard' bsd-type install program
 INSTALL  ?= install
 RM       ?= rm -f
 
 ASCIIDOC         = asciidoc
-ASCIIDOC_CONF    = -f ../../Documentation/asciidoc.conf
+ASCIIDOC_CONF    = -f asciidoc.conf
 ASCIIDOC_HTML    = xhtml11
 ASCIIDOC_DOCBOOK = docbook
 ASCIIDOC_EXTRA   =
+ASCIIDOC_DEPS    = asciidoc.conf
 XMLTO            = xmlto
 XMLTO_EXTRA      =
 
@@ -32,8 +32,9 @@ ASCIIDOC         = asciidoctor
 ASCIIDOC_CONF    =
 ASCIIDOC_HTML    = xhtml5
 ASCIIDOC_DOCBOOK = docbook
-ASCIIDOC_EXTRA  += -I../../Documentation -rasciidoctor-extensions
+ASCIIDOC_EXTRA  += -I. -rasciidoctor-extensions
 ASCIIDOC_EXTRA  += -alitdd='&\#x2d;&\#x2d;'
+ASCIIDOC_DEPS    = asciidoctor-extensions.rb
 XMLTO_EXTRA     += --skip-validation
 endif
 
@@ -49,7 +50,7 @@ GIT_SUBTREE    := git-subtree
 
 GIT_SUBTREE_DOC := git-subtree.1
 GIT_SUBTREE_XML := git-subtree.xml
-GIT_SUBTREE_TXT := git-subtree.txt
+GIT_SUBTREE_TXT := git-subtree.adoc
 GIT_SUBTREE_HTML := git-subtree.html
 GIT_SUBTREE_TEST := ../../git-subtree
 
@@ -82,13 +83,13 @@ install-html: $(GIT_SUBTREE_HTML)
 $(GIT_SUBTREE_DOC): $(GIT_SUBTREE_XML)
 	$(XMLTO) -m $(MANPAGE_XSL) $(XMLTO_EXTRA) man $^
 
-$(GIT_SUBTREE_XML): $(GIT_SUBTREE_TXT)
+$(GIT_SUBTREE_XML): $(GIT_SUBTREE_TXT) $(ASCIIDOC_DEPS)
 	$(ASCIIDOC) -b $(ASCIIDOC_DOCBOOK) -d manpage $(ASCIIDOC_CONF) \
-		-agit_version=$(GIT_VERSION) $(ASCIIDOC_EXTRA) $^
+		$(ASCIIDOC_EXTRA) $<
 
-$(GIT_SUBTREE_HTML): $(GIT_SUBTREE_TXT)
+$(GIT_SUBTREE_HTML): $(GIT_SUBTREE_TXT) $(ASCIIDOC_DEPS)
 	$(ASCIIDOC) -b $(ASCIIDOC_HTML) -d manpage $(ASCIIDOC_CONF) \
-		-agit_version=$(GIT_VERSION) $(ASCIIDOC_EXTRA) $^
+		$(ASCIIDOC_EXTRA) $<
 
 $(GIT_SUBTREE_TEST): $(GIT_SUBTREE)
 	cp $< $@
@@ -98,6 +99,12 @@ test: $(GIT_SUBTREE_TEST)
 
 clean:
 	$(RM) $(GIT_SUBTREE)
+	$(RM) asciidoc.conf asciidoctor-extensions.rb
 	$(RM) *.xml *.html *.1
 
+asciidoc.conf: ../../Documentation/asciidoc.conf.in ../../GIT-VERSION-FILE
+	$(QUIET_GEN)$(call version_gen,"$(shell pwd)/../..",$<,$@)
+asciidoctor-extensions.rb: ../../Documentation/asciidoctor-extensions.rb.in ../../GIT-VERSION-FILE
+	$(QUIET_GEN)$(call version_gen,"$(shell pwd)/../..",$<,$@)
+
 .PHONY: FORCE
diff --git a/contrib/subtree/git-subtree.txt b/contrib/subtree/git-subtree.adoc
index 004abf415b..004abf415b 100644
--- a/contrib/subtree/git-subtree.txt
+++ b/contrib/subtree/git-subtree.adoc
diff --git a/contrib/subtree/meson.build b/contrib/subtree/meson.build
new file mode 100644
index 0000000000..63714166a6
--- /dev/null
+++ b/contrib/subtree/meson.build
@@ -0,0 +1,73 @@
+git_subtree = custom_target(
+  input: 'git-subtree.sh',
+  output: 'git-subtree',
+  command: [
+    shell,
+    meson.project_source_root() / 'generate-script.sh',
+    '@INPUT@',
+    '@OUTPUT@',
+    meson.project_build_root() / 'GIT-BUILD-OPTIONS',
+  ],
+  install: true,
+  install_dir: get_option('libexecdir') / 'git-core',
+)
+
+if get_option('tests')
+  subtree_test_environment = test_environment
+  subtree_test_environment.prepend('PATH', meson.current_build_dir())
+
+  test('t7900-subtree', shell,
+    args: [ 't7900-subtree.sh' ],
+    env: subtree_test_environment,
+    workdir: meson.current_source_dir() / 't',
+    depends: test_dependencies + bin_wrappers + [ git_subtree ],
+    timeout: 0,
+  )
+endif
+
+if get_option('docs').contains('man')
+  subtree_xml = custom_target(
+    command: asciidoc_common_options + [
+      '--backend=' + asciidoc_docbook,
+      '--doctype=manpage',
+      '--out-file=@OUTPUT@',
+      '@INPUT@',
+    ],
+    depends: documentation_deps,
+    input: 'git-subtree.adoc',
+    output: 'git-subtree.xml',
+  )
+
+  custom_target(
+    command: [
+      xmlto,
+      '-m', '@INPUT@',
+      'man',
+      subtree_xml,
+      '-o',
+      meson.current_build_dir(),
+    ] + xmlto_extra,
+    input: [
+      '../../Documentation/manpage-normal.xsl',
+    ],
+    output: 'git-subtree.1',
+    install: true,
+    install_dir: get_option('mandir') / 'man1',
+  )
+endif
+
+if get_option('docs').contains('html')
+  custom_target(
+    command: asciidoc_common_options + [
+      '--backend=' + asciidoc_html,
+      '--doctype=manpage',
+      '--out-file=@OUTPUT@',
+      '@INPUT@',
+    ],
+    depends: documentation_deps,
+    input: 'git-subtree.adoc',
+    output: 'git-subtree.html',
+    install: true,
+    install_dir: get_option('datadir') / 'doc/git-doc',
+  )
+endif
diff --git a/contrib/subtree/t/Makefile b/contrib/subtree/t/Makefile
index 093399c788..2a85f5ee84 100644
--- a/contrib/subtree/t/Makefile
+++ b/contrib/subtree/t/Makefile
@@ -3,6 +3,9 @@
 # Copyright (c) 2005 Junio C Hamano
 #
 
+# The default target of this Makefile is...
+all::
+
 -include ../../../config.mak.autogen
 -include ../../../config.mak
 
@@ -31,7 +34,7 @@ TSVN = $(sort $(wildcard t91[0-9][0-9]-*.sh))
 TGITWEB = $(sort $(wildcard t95[0-9][0-9]-*.sh))
 THELPERS = $(sort $(filter-out $(T),$(wildcard *.sh)))
 
-all: $(DEFAULT_TEST_TARGET)
+all:: $(DEFAULT_TEST_TARGET)
 
 test: pre-clean $(TEST_LINT)
 	$(MAKE) aggregate-results-and-cleanup
diff --git a/contrib/thunderbird-patch-inline/appp.sh b/contrib/thunderbird-patch-inline/appp.sh
index 1053872eea..fdcc948352 100755
--- a/contrib/thunderbird-patch-inline/appp.sh
+++ b/contrib/thunderbird-patch-inline/appp.sh
@@ -31,7 +31,7 @@ BODY=$(sed -e "1,/${SEP}/d" $1)
 CMT_MSG=$(sed -e '1,/^$/d' -e '/^---$/,$d' "${PATCH}")
 DIFF=$(sed -e '1,/^---$/d' "${PATCH}")
 
-CCS=$(echo -e "$CMT_MSG\n$HEADERS" | sed -n -e 's/^Cc: \(.*\)$/\1,/gp' \
+CCS=$(printf '%s\n%s\n' "$CMT_MSG" "$HEADERS" | sed -n -e 's/^Cc: \(.*\)$/\1,/gp' \
 	-e 's/^Signed-off-by: \(.*\)/\1,/gp')
 
 echo "$SUBJECT" > $1