26 files changed, 1526 insertions, 250 deletions
diff --git a/t/README b/t/README
index 0f764c0aef..4982d1c521 100644
--- a/t/README
+++ b/t/README
@@ -153,6 +153,12 @@ appropriately before running "make".
 	As the names depend on the tests' file names, it is safe to
 	run the tests with this option in parallel.
 
+--verbose-log::
+	Write verbose output to the same logfile as `--tee`, but do
+	_not_ write it to stdout. Unlike `--tee --verbose`, this option
+	is safe to use when stdout is being consumed by a TAP parser
+	like `prove`. Implies `--tee` and `--verbose`.
+
 --with-dashes::
 	By default tests are run without dashed forms of
 	commands (like git-commit) in the PATH (it only uses
diff --git a/t/helper/test-dump-cache-tree.c b/t/helper/test-dump-cache-tree.c
index 44f3290258..7af116d49e 100644
--- a/t/helper/test-dump-cache-tree.c
+++ b/t/helper/test-dump-cache-tree.c
@@ -58,6 +58,7 @@ int cmd_main(int ac, const char **av)
 {
 	struct index_state istate;
 	struct cache_tree *another = cache_tree();
+	setup_git_directory();
 	if (read_cache() < 0)
 		die("unable to read index file");
 	istate = the_index;
diff --git a/t/helper/test-scrap-cache-tree.c b/t/helper/test-scrap-cache-tree.c
index 5b2fd09908..27fe0405b8 100644
--- a/t/helper/test-scrap-cache-tree.c
+++ b/t/helper/test-scrap-cache-tree.c
@@ -7,6 +7,7 @@ static struct lock_file index_lock;
 
 int cmd_main(int ac, const char **av)
 {
+	setup_git_directory();
 	hold_locked_index(&index_lock, 1);
 	if (read_cache() < 0)
 		die("unable to read index file");
diff --git a/t/perf/p5550-fetch-tags.sh b/t/perf/p5550-fetch-tags.sh
new file mode 100755
index 0000000000..a5dc39f86a
--- /dev/null
+++ b/t/perf/p5550-fetch-tags.sh
@@ -0,0 +1,99 @@
+#!/bin/sh
+
+test_description='performance of tag-following with many tags
+
+This tests a fairly pathological case, so rather than rely on a real-world
+case, we will construct our own repository. The situation is roughly as
+follows.
+
+The parent repository has a large number of tags which are disconnected from
+the rest of history. That makes them candidates for tag-following, but we never
+actually grab them (and thus they will impact each subsequent fetch).
+
+The child repository is a clone of parent, without the tags, and is at least
+one commit behind the parent (meaning that we will fetch one object and then
+examine the tags to see if they need followed). Furthermore, it has a large
+number of packs.
+
+The exact values of "large" here are somewhat arbitrary; I picked values that
+start to show a noticeable performance problem on my machine, but without
+taking too long to set up and run the tests.
+'
+. ./perf-lib.sh
+
+# make a long nonsense history on branch $1, consisting of $2 commits, each
+# with a unique file pointing to the blob at $2.
+create_history () {
+	perl -le '
+		my ($branch, $n, $blob) = @ARGV;
+		for (1..$n) {
+			print "commit refs/heads/$branch";
+			print "committer nobody <nobody@example.com> now";
+			print "data 4";
+			print "foo";
+			print "M 100644 $blob $_";
+		}
+	' "$@" |
+	git fast-import --date-format=now
+}
+
+# make a series of tags, one per commit in the revision range given by $@
+create_tags () {
+	git rev-list "$@" |
+	perl -lne 'print "create refs/tags/$. $_"' |
+	git update-ref --stdin
+}
+
+# create $1 nonsense packs, each with a single blob
+create_packs () {
+	perl -le '
+		my ($n) = @ARGV;
+		for (1..$n) {
+			print "blob";
+			print "data <<EOF";
+			print "$_";
+			print "EOF";
+		}
+	' "$@" |
+	git fast-import &&
+
+	git cat-file --batch-all-objects --batch-check='%(objectname)' |
+	while read sha1
+	do
+		echo $sha1 | git pack-objects .git/objects/pack/pack
+	done
+}
+
+test_expect_success 'create parent and child' '
+	git init parent &&
+	git -C parent commit --allow-empty -m base &&
+	git clone parent child &&
+	git -C parent commit --allow-empty -m trigger-fetch
+'
+
+test_expect_success 'populate parent tags' '
+	(
+		cd parent &&
+		blob=$(echo content | git hash-object -w --stdin) &&
+		create_history cruft 3000 $blob &&
+		create_tags cruft &&
+		git branch -D cruft
+	)
+'
+
+test_expect_success 'create child packs' '
+	(
+		cd child &&
+		git config gc.auto 0 &&
+		git config gc.autopacklimit 0 &&
+		create_packs 500
+	)
+'
+
+test_perf 'fetch' '
+	# make sure there is something to fetch on each iteration
+	git -C child update-ref -d refs/remotes/origin/master &&
+	git -C child fetch
+'
+
+test_done
diff --git a/t/t0020-crlf.sh b/t/t0020-crlf.sh
index f94120a894..71350e0657 100755
--- a/t/t0020-crlf.sh
+++ b/t/t0020-crlf.sh
@@ -83,7 +83,11 @@ test_expect_success 'safecrlf: print warning only once' '
 	git add doublewarn &&
 	git commit -m "nowarn" &&
 	for w in Oh here is CRLFQ in text; do echo $w; done | q_to_cr >doublewarn &&
-	test $(git add doublewarn 2>&1 | grep "CRLF will be replaced by LF" | wc -l) = 1
+	git add doublewarn 2>err &&
+	if test_have_prereq C_LOCALE_OUTPUT
+	then
+		test $(grep "CRLF will be replaced by LF" err | wc -l) = 1
+	fi
 '
 
 
diff --git a/t/t0021-conversion.sh b/t/t0021-conversion.sh
index e799e59544..a20b9f58e3 100755
--- a/t/t0021-conversion.sh
+++ b/t/t0021-conversion.sh
@@ -4,13 +4,72 @@ test_description='blob conversion via gitattributes'
 
 . ./test-lib.sh
 
-cat <<EOF >rot13.sh
+TEST_ROOT="$(pwd)"
+
+cat <<EOF >"$TEST_ROOT/rot13.sh"
 #!$SHELL_PATH
 tr \
   'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ' \
   'nopqrstuvwxyzabcdefghijklmNOPQRSTUVWXYZABCDEFGHIJKLM'
 EOF
-chmod +x rot13.sh
+chmod +x "$TEST_ROOT/rot13.sh"
+
+generate_random_characters () {
+	LEN=$1
+	NAME=$2
+	test-genrandom some-seed $LEN |
+		perl -pe "s/./chr((ord($&) % 26) + ord('a'))/sge" >"$TEST_ROOT/$NAME"
+}
+
+file_size () {
+	cat "$1" | wc -c | sed "s/^[ ]*//"
+}
+
+filter_git () {
+	rm -f rot13-filter.log &&
+	git "$@" 2>git-stderr.log &&
+	rm -f git-stderr.log
+}
+
+# Compare two files and ensure that `clean` and `smudge` respectively are
+# called at least once if specified in the `expect` file. The actual
+# invocation count is not relevant because their number can vary.
+# c.f. http://public-inbox.org/git/xmqqshv18i8i.fsf@gitster.mtv.corp.google.com/
+test_cmp_count () {
+	expect=$1
+	actual=$2
+	for FILE in "$expect" "$actual"
+	do
+		sort "$FILE" | uniq -c | sed "s/^[ ]*//" |
+			sed "s/^\([0-9]\) IN: clean/x IN: clean/" |
+			sed "s/^\([0-9]\) IN: smudge/x IN: smudge/" >"$FILE.tmp" &&
+		mv "$FILE.tmp" "$FILE"
+	done &&
+	test_cmp "$expect" "$actual"
+}
+
+# Compare two files but exclude all `clean` invocations because Git can
+# call `clean` zero or more times.
+# c.f. http://public-inbox.org/git/xmqqshv18i8i.fsf@gitster.mtv.corp.google.com/
+test_cmp_exclude_clean () {
+	expect=$1
+	actual=$2
+	for FILE in "$expect" "$actual"
+	do
+		grep -v "IN: clean" "$FILE" >"$FILE.tmp" &&
+		mv "$FILE.tmp" "$FILE"
+	done &&
+	test_cmp "$expect" "$actual"
+}
+
+# Check that the contents of two files are equal and that their rot13 version
+# is equal to the committed content.
+test_cmp_committed_rot13 () {
+	test_cmp "$1" "$2" &&
+	"$TEST_ROOT/rot13.sh" <"$1" >expected &&
+	git cat-file blob :"$2" >actual &&
+	test_cmp expected actual
+}
 
 test_expect_success setup '
 	git config filter.rot13.smudge ./rot13.sh &&
@@ -31,15 +90,18 @@ test_expect_success setup '
 	cat test >test.i &&
 	git add test test.t test.i &&
 	rm -f test test.t test.i &&
-	git checkout -- test test.t test.i
+	git checkout -- test test.t test.i &&
+
+	echo "content-test2" >test2.o &&
+	echo "content-test3 - filename with special characters" >"test3 '\''sq'\'',\$x.o"
 '
 
 script='s/^\$Id: \([0-9a-f]*\) \$/\1/p'
 
 test_expect_success check '
 
-	cmp test.o test &&
-	cmp test.o test.t &&
+	test_cmp test.o test &&
+	test_cmp test.o test.t &&
 
 	# ident should be stripped in the repository
 	git diff --raw --exit-code :test :test.i &&
@@ -47,10 +109,10 @@ test_expect_success check '
 	embedded=$(sed -ne "$script" test.i) &&
 	test "z$id" = "z$embedded" &&
 
-	git cat-file blob :test.t > test.r &&
+	git cat-file blob :test.t >test.r &&
 
-	./rot13.sh < test.o > test.t &&
-	cmp test.r test.t
+	./rot13.sh <test.o >test.t &&
+	test_cmp test.r test.t
 '
 
 # If an expanded ident ever gets into the repository, we want to make sure that
@@ -130,7 +192,7 @@ test_expect_success 'filter shell-escaped filenames' '
 
 	# delete the files and check them out again, using a smudge filter
 	# that will count the args and echo the command-line back to us
-	git config filter.argc.smudge "sh ./argc.sh %f" &&
+	test_config filter.argc.smudge "sh ./argc.sh %f" &&
 	rm "$normal" "$special" &&
 	git checkout -- "$normal" "$special" &&
 
@@ -141,7 +203,7 @@ test_expect_success 'filter shell-escaped filenames' '
 	test_cmp expect "$special" &&
 
 	# do the same thing, but with more args in the filter expression
-	git config filter.argc.smudge "sh ./argc.sh %f --my-extra-arg" &&
+	test_config filter.argc.smudge "sh ./argc.sh %f --my-extra-arg" &&
 	rm "$normal" "$special" &&
 	git checkout -- "$normal" "$special" &&
 
@@ -154,9 +216,9 @@ test_expect_success 'filter shell-escaped filenames' '
 '
 
 test_expect_success 'required filter should filter data' '
-	git config filter.required.smudge ./rot13.sh &&
-	git config filter.required.clean ./rot13.sh &&
-	git config filter.required.required true &&
+	test_config filter.required.smudge ./rot13.sh &&
+	test_config filter.required.clean ./rot13.sh &&
+	test_config filter.required.required true &&
 
 	echo "*.r filter=required" >.gitattributes &&
 
@@ -165,17 +227,17 @@ test_expect_success 'required filter should filter data' '
 
 	rm -f test.r &&
 	git checkout -- test.r &&
-	cmp test.o test.r &&
+	test_cmp test.o test.r &&
 
 	./rot13.sh <test.o >expected &&
 	git cat-file blob :test.r >actual &&
-	cmp expected actual
+	test_cmp expected actual
 '
 
 test_expect_success 'required filter smudge failure' '
-	git config filter.failsmudge.smudge false &&
-	git config filter.failsmudge.clean cat &&
-	git config filter.failsmudge.required true &&
+	test_config filter.failsmudge.smudge false &&
+	test_config filter.failsmudge.clean cat &&
+	test_config filter.failsmudge.required true &&
 
 	echo "*.fs filter=failsmudge" >.gitattributes &&
 
@@ -186,9 +248,9 @@ test_expect_success 'required filter smudge failure' '
 '
 
 test_expect_success 'required filter clean failure' '
-	git config filter.failclean.smudge cat &&
-	git config filter.failclean.clean false &&
-	git config filter.failclean.required true &&
+	test_config filter.failclean.smudge cat &&
+	test_config filter.failclean.clean false &&
+	test_config filter.failclean.required true &&
 
 	echo "*.fc filter=failclean" >.gitattributes &&
 
@@ -197,8 +259,8 @@ test_expect_success 'required filter clean failure' '
 '
 
 test_expect_success 'filtering large input to small output should use little memory' '
-	git config filter.devnull.clean "cat >/dev/null" &&
-	git config filter.devnull.required true &&
+	test_config filter.devnull.clean "cat >/dev/null" &&
+	test_config filter.devnull.required true &&
 	for i in $(test_seq 1 30); do printf "%1048576d" 1; done >30MB &&
 	echo "30MB filter=devnull" >.gitattributes &&
 	GIT_MMAP_LIMIT=1m GIT_ALLOC_LIMIT=1m git add 30MB
@@ -207,7 +269,7 @@ test_expect_success 'filtering large input to small output should use little mem
 test_expect_success 'filter that does not read is fine' '
 	test-genrandom foo $((128 * 1024 + 1)) >big &&
 	echo "big filter=epipe" >.gitattributes &&
-	git config filter.epipe.clean "echo xyzzy" &&
+	test_config filter.epipe.clean "echo xyzzy" &&
 	git add big &&
 	git cat-file blob :big >actual &&
 	echo xyzzy >expect &&
@@ -215,20 +277,20 @@ test_expect_success 'filter that does not read is fine' '
 '
 
 test_expect_success EXPENSIVE 'filter large file' '
-	git config filter.largefile.smudge cat &&
-	git config filter.largefile.clean cat &&
+	test_config filter.largefile.smudge cat &&
+	test_config filter.largefile.clean cat &&
 	for i in $(test_seq 1 2048); do printf "%1048576d" 1; done >2GB &&
 	echo "2GB filter=largefile" >.gitattributes &&
 	git add 2GB 2>err &&
-	! test -s err &&
+	test_must_be_empty err &&
 	rm -f 2GB &&
 	git checkout -- 2GB 2>err &&
-	! test -s err
+	test_must_be_empty err
 '
 
 test_expect_success "filter: clean empty file" '
-	git config filter.in-repo-header.clean  "echo cleaned && cat" &&
-	git config filter.in-repo-header.smudge "sed 1d" &&
+	test_config filter.in-repo-header.clean  "echo cleaned && cat" &&
+	test_config filter.in-repo-header.smudge "sed 1d" &&
 
 	echo "empty-in-worktree    filter=in-repo-header" >>.gitattributes &&
 	>empty-in-worktree &&
@@ -240,8 +302,8 @@ test_expect_success "filter: clean empty file" '
 '
 
 test_expect_success "filter: smudge empty file" '
-	git config filter.empty-in-repo.clean "cat >/dev/null" &&
-	git config filter.empty-in-repo.smudge "echo smudged && cat" &&
+	test_config filter.empty-in-repo.clean "cat >/dev/null" &&
+	test_config filter.empty-in-repo.smudge "echo smudged && cat" &&
 
 	echo "empty-in-repo filter=empty-in-repo" >>.gitattributes &&
 	echo dead data walking >empty-in-repo &&
@@ -279,4 +341,380 @@ test_expect_success 'diff does not reuse worktree files that need cleaning' '
 	test_line_count = 0 count
 '
 
+test_expect_success PERL 'required process filter should filter data' '
+	test_config_global filter.protocol.process "$TEST_DIRECTORY/t0021/rot13-filter.pl clean smudge" &&
+	test_config_global filter.protocol.required true &&
+	rm -rf repo &&
+	mkdir repo &&
+	(
+		cd repo &&
+		git init &&
+
+		echo "git-stderr.log" >.gitignore &&
+		echo "*.r filter=protocol" >.gitattributes &&
+		git add . &&
+		git commit . -m "test commit 1" &&
+		git branch empty-branch &&
+
+		cp "$TEST_ROOT/test.o" test.r &&
+		cp "$TEST_ROOT/test2.o" test2.r &&
+		mkdir testsubdir &&
+		cp "$TEST_ROOT/test3 '\''sq'\'',\$x.o" "testsubdir/test3 '\''sq'\'',\$x.r" &&
+		>test4-empty.r &&
+
+		S=$(file_size test.r) &&
+		S2=$(file_size test2.r) &&
+		S3=$(file_size "testsubdir/test3 '\''sq'\'',\$x.r") &&
+
+		filter_git add . &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: clean test.r $S [OK] -- OUT: $S . [OK]
+			IN: clean test2.r $S2 [OK] -- OUT: $S2 . [OK]
+			IN: clean test4-empty.r 0 [OK] -- OUT: 0  [OK]
+			IN: clean testsubdir/test3 '\''sq'\'',\$x.r $S3 [OK] -- OUT: $S3 . [OK]
+			STOP
+		EOF
+		test_cmp_count expected.log rot13-filter.log &&
+
+		filter_git commit . -m "test commit 2" &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: clean test.r $S [OK] -- OUT: $S . [OK]
+			IN: clean test2.r $S2 [OK] -- OUT: $S2 . [OK]
+			IN: clean test4-empty.r 0 [OK] -- OUT: 0  [OK]
+			IN: clean testsubdir/test3 '\''sq'\'',\$x.r $S3 [OK] -- OUT: $S3 . [OK]
+			IN: clean test.r $S [OK] -- OUT: $S . [OK]
+			IN: clean test2.r $S2 [OK] -- OUT: $S2 . [OK]
+			IN: clean test4-empty.r 0 [OK] -- OUT: 0  [OK]
+			IN: clean testsubdir/test3 '\''sq'\'',\$x.r $S3 [OK] -- OUT: $S3 . [OK]
+			STOP
+		EOF
+		test_cmp_count expected.log rot13-filter.log &&
+
+		rm -f test2.r "testsubdir/test3 '\''sq'\'',\$x.r" &&
+
+		filter_git checkout --quiet --no-progress . &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: smudge test2.r $S2 [OK] -- OUT: $S2 . [OK]
+			IN: smudge testsubdir/test3 '\''sq'\'',\$x.r $S3 [OK] -- OUT: $S3 . [OK]
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log rot13-filter.log &&
+
+		filter_git checkout --quiet --no-progress empty-branch &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: clean test.r $S [OK] -- OUT: $S . [OK]
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log rot13-filter.log &&
+
+		filter_git checkout --quiet --no-progress master &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: smudge test.r $S [OK] -- OUT: $S . [OK]
+			IN: smudge test2.r $S2 [OK] -- OUT: $S2 . [OK]
+			IN: smudge test4-empty.r 0 [OK] -- OUT: 0  [OK]
+			IN: smudge testsubdir/test3 '\''sq'\'',\$x.r $S3 [OK] -- OUT: $S3 . [OK]
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log rot13-filter.log &&
+
+		test_cmp_committed_rot13 "$TEST_ROOT/test.o" test.r &&
+		test_cmp_committed_rot13 "$TEST_ROOT/test2.o" test2.r &&
+		test_cmp_committed_rot13 "$TEST_ROOT/test3 '\''sq'\'',\$x.o" "testsubdir/test3 '\''sq'\'',\$x.r"
+	)
+'
+
+test_expect_success PERL 'required process filter takes precedence' '
+	test_config_global filter.protocol.clean false &&
+	test_config_global filter.protocol.process "$TEST_DIRECTORY/t0021/rot13-filter.pl clean" &&
+	test_config_global filter.protocol.required true &&
+	rm -rf repo &&
+	mkdir repo &&
+	(
+		cd repo &&
+		git init &&
+
+		echo "*.r filter=protocol" >.gitattributes &&
+		cp "$TEST_ROOT/test.o" test.r &&
+		S=$(file_size test.r) &&
+
+		# Check that the process filter is invoked here
+		filter_git add . &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: clean test.r $S [OK] -- OUT: $S . [OK]
+			STOP
+		EOF
+		test_cmp_count expected.log rot13-filter.log
+	)
+'
+
+test_expect_success PERL 'required process filter should be used only for "clean" operation only' '
+	test_config_global filter.protocol.process "$TEST_DIRECTORY/t0021/rot13-filter.pl clean" &&
+	rm -rf repo &&
+	mkdir repo &&
+	(
+		cd repo &&
+		git init &&
+
+		echo "*.r filter=protocol" >.gitattributes &&
+		cp "$TEST_ROOT/test.o" test.r &&
+		S=$(file_size test.r) &&
+
+		filter_git add . &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: clean test.r $S [OK] -- OUT: $S . [OK]
+			STOP
+		EOF
+		test_cmp_count expected.log rot13-filter.log &&
+
+		rm test.r &&
+
+		filter_git checkout --quiet --no-progress . &&
+		# If the filter would be used for "smudge", too, we would see
+		# "IN: smudge test.r 57 [OK] -- OUT: 57 . [OK]" here
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log rot13-filter.log
+	)
+'
+
+test_expect_success PERL 'required process filter should process multiple packets' '
+	test_config_global filter.protocol.process "$TEST_DIRECTORY/t0021/rot13-filter.pl clean smudge" &&
+	test_config_global filter.protocol.required true &&
+
+	rm -rf repo &&
+	mkdir repo &&
+	(
+		cd repo &&
+		git init &&
+
+		# Generate data requiring 1, 2, 3 packets
+		S=65516 && # PKTLINE_DATA_MAXLEN -> Maximal size of a packet
+		generate_random_characters $(($S    )) 1pkt_1__.file &&
+		generate_random_characters $(($S  +1)) 2pkt_1+1.file &&
+		generate_random_characters $(($S*2-1)) 2pkt_2-1.file &&
+		generate_random_characters $(($S*2  )) 2pkt_2__.file &&
+		generate_random_characters $(($S*2+1)) 3pkt_2+1.file &&
+
+		for FILE in "$TEST_ROOT"/*.file
+		do
+			cp "$FILE" . &&
+			"$TEST_ROOT/rot13.sh" <"$FILE" >"$FILE.rot13"
+		done &&
+
+		echo "*.file filter=protocol" >.gitattributes &&
+		filter_git add *.file .gitattributes &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: clean 1pkt_1__.file $(($S    )) [OK] -- OUT: $(($S    )) . [OK]
+			IN: clean 2pkt_1+1.file $(($S  +1)) [OK] -- OUT: $(($S  +1)) .. [OK]
+			IN: clean 2pkt_2-1.file $(($S*2-1)) [OK] -- OUT: $(($S*2-1)) .. [OK]
+			IN: clean 2pkt_2__.file $(($S*2  )) [OK] -- OUT: $(($S*2  )) .. [OK]
+			IN: clean 3pkt_2+1.file $(($S*2+1)) [OK] -- OUT: $(($S*2+1)) ... [OK]
+			STOP
+		EOF
+		test_cmp_count expected.log rot13-filter.log &&
+
+		rm -f *.file &&
+
+		filter_git checkout --quiet --no-progress -- *.file &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: smudge 1pkt_1__.file $(($S    )) [OK] -- OUT: $(($S    )) . [OK]
+			IN: smudge 2pkt_1+1.file $(($S  +1)) [OK] -- OUT: $(($S  +1)) .. [OK]
+			IN: smudge 2pkt_2-1.file $(($S*2-1)) [OK] -- OUT: $(($S*2-1)) .. [OK]
+			IN: smudge 2pkt_2__.file $(($S*2  )) [OK] -- OUT: $(($S*2  )) .. [OK]
+			IN: smudge 3pkt_2+1.file $(($S*2+1)) [OK] -- OUT: $(($S*2+1)) ... [OK]
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log rot13-filter.log &&
+
+		for FILE in *.file
+		do
+			test_cmp_committed_rot13 "$TEST_ROOT/$FILE" $FILE
+		done
+	)
+'
+
+test_expect_success PERL 'required process filter with clean error should fail' '
+	test_config_global filter.protocol.process "$TEST_DIRECTORY/t0021/rot13-filter.pl clean smudge" &&
+	test_config_global filter.protocol.required true &&
+	rm -rf repo &&
+	mkdir repo &&
+	(
+		cd repo &&
+		git init &&
+
+		echo "*.r filter=protocol" >.gitattributes &&
+
+		cp "$TEST_ROOT/test.o" test.r &&
+		echo "this is going to fail" >clean-write-fail.r &&
+		echo "content-test3-subdir" >test3.r &&
+
+		test_must_fail git add .
+	)
+'
+
+test_expect_success PERL 'process filter should restart after unexpected write failure' '
+	test_config_global filter.protocol.process "$TEST_DIRECTORY/t0021/rot13-filter.pl clean smudge" &&
+	rm -rf repo &&
+	mkdir repo &&
+	(
+		cd repo &&
+		git init &&
+
+		echo "*.r filter=protocol" >.gitattributes &&
+
+		cp "$TEST_ROOT/test.o" test.r &&
+		cp "$TEST_ROOT/test2.o" test2.r &&
+		echo "this is going to fail" >smudge-write-fail.o &&
+		cp smudge-write-fail.o smudge-write-fail.r &&
+
+		S=$(file_size test.r) &&
+		S2=$(file_size test2.r) &&
+		SF=$(file_size smudge-write-fail.r) &&
+
+		git add . &&
+		rm -f *.r &&
+
+		rm -f rot13-filter.log &&
+		git checkout --quiet --no-progress . 2>git-stderr.log &&
+
+		grep "smudge write error at" git-stderr.log &&
+		grep "error: external filter" git-stderr.log &&
+
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: smudge smudge-write-fail.r $SF [OK] -- OUT: $SF [WRITE FAIL]
+			START
+			init handshake complete
+			IN: smudge test.r $S [OK] -- OUT: $S . [OK]
+			IN: smudge test2.r $S2 [OK] -- OUT: $S2 . [OK]
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log rot13-filter.log &&
+
+		test_cmp_committed_rot13 "$TEST_ROOT/test.o" test.r &&
+		test_cmp_committed_rot13 "$TEST_ROOT/test2.o" test2.r &&
+
+		# Smudge failed
+		! test_cmp smudge-write-fail.o smudge-write-fail.r &&
+		"$TEST_ROOT/rot13.sh" <smudge-write-fail.o >expected &&
+		git cat-file blob :smudge-write-fail.r >actual &&
+		test_cmp expected actual
+	)
+'
+
+test_expect_success PERL 'process filter should not be restarted if it signals an error' '
+	test_config_global filter.protocol.process "$TEST_DIRECTORY/t0021/rot13-filter.pl clean smudge" &&
+	rm -rf repo &&
+	mkdir repo &&
+	(
+		cd repo &&
+		git init &&
+
+		echo "*.r filter=protocol" >.gitattributes &&
+
+		cp "$TEST_ROOT/test.o" test.r &&
+		cp "$TEST_ROOT/test2.o" test2.r &&
+		echo "this will cause an error" >error.o &&
+		cp error.o error.r &&
+
+		S=$(file_size test.r) &&
+		S2=$(file_size test2.r) &&
+		SE=$(file_size error.r) &&
+
+		git add . &&
+		rm -f *.r &&
+
+		filter_git checkout --quiet --no-progress . &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: smudge error.r $SE [OK] -- OUT: 0 [ERROR]
+			IN: smudge test.r $S [OK] -- OUT: $S . [OK]
+			IN: smudge test2.r $S2 [OK] -- OUT: $S2 . [OK]
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log rot13-filter.log &&
+
+		test_cmp_committed_rot13 "$TEST_ROOT/test.o" test.r &&
+		test_cmp_committed_rot13 "$TEST_ROOT/test2.o" test2.r &&
+		test_cmp error.o error.r
+	)
+'
+
+test_expect_success PERL 'process filter abort stops processing of all further files' '
+	test_config_global filter.protocol.process "$TEST_DIRECTORY/t0021/rot13-filter.pl clean smudge" &&
+	rm -rf repo &&
+	mkdir repo &&
+	(
+		cd repo &&
+		git init &&
+
+		echo "*.r filter=protocol" >.gitattributes &&
+
+		cp "$TEST_ROOT/test.o" test.r &&
+		cp "$TEST_ROOT/test2.o" test2.r &&
+		echo "error this blob and all future blobs" >abort.o &&
+		cp abort.o abort.r &&
+
+		SA=$(file_size abort.r) &&
+
+		git add . &&
+		rm -f *.r &&
+
+		# Note: This test assumes that Git filters files in alphabetical
+		# order ("abort.r" before "test.r").
+		filter_git checkout --quiet --no-progress . &&
+		cat >expected.log <<-EOF &&
+			START
+			init handshake complete
+			IN: smudge abort.r $SA [OK] -- OUT: 0 [ABORT]
+			STOP
+		EOF
+		test_cmp_exclude_clean expected.log rot13-filter.log &&
+
+		test_cmp "$TEST_ROOT/test.o" test.r &&
+		test_cmp "$TEST_ROOT/test2.o" test2.r &&
+		test_cmp abort.o abort.r
+	)
+'
+
+test_expect_success PERL 'invalid process filter must fail (and not hang!)' '
+	test_config_global filter.protocol.process cat &&
+	test_config_global filter.protocol.required true &&
+	rm -rf repo &&
+	mkdir repo &&
+	(
+		cd repo &&
+		git init &&
+
+		echo "*.r filter=protocol" >.gitattributes &&
+
+		cp "$TEST_ROOT/test.o" test.r &&
+		test_must_fail git add . 2>git-stderr.log &&
+		grep "does not support filter protocol version" git-stderr.log
+	)
+'
+
 test_done
diff --git a/t/t0021/rot13-filter.pl b/t/t0021/rot13-filter.pl
new file mode 100755
index 0000000000..ae4c50f5c5
--- /dev/null
+++ b/t/t0021/rot13-filter.pl
@@ -0,0 +1,192 @@
+#!/usr/bin/perl
+#
+# Example implementation for the Git filter protocol version 2
+# See Documentation/gitattributes.txt, section "Filter Protocol"
+#
+# The script takes the list of supported protocol capabilities as
+# arguments ("clean", "smudge", etc).
+#
+# This implementation supports special test cases:
+# (1) If data with the pathname "clean-write-fail.r" is processed with
+#     a "clean" operation then the write operation will die.
+# (2) If data with the pathname "smudge-write-fail.r" is processed with
+#     a "smudge" operation then the write operation will die.
+# (3) If data with the pathname "error.r" is processed with any
+#     operation then the filter signals that it cannot or does not want
+#     to process the file.
+# (4) If data with the pathname "abort.r" is processed with any
+#     operation then the filter signals that it cannot or does not want
+#     to process the file and any file after that is processed with the
+#     same command.
+#
+
+use strict;
+use warnings;
+
+my $MAX_PACKET_CONTENT_SIZE = 65516;
+my @capabilities            = @ARGV;
+
+open my $debug, ">>", "rot13-filter.log" or die "cannot open log file: $!";
+
+sub rot13 {
+	my $str = shift;
+	$str =~ y/A-Za-z/N-ZA-Mn-za-m/;
+	return $str;
+}
+
+sub packet_bin_read {
+	my $buffer;
+	my $bytes_read = read STDIN, $buffer, 4;
+	if ( $bytes_read == 0 ) {
+		# EOF - Git stopped talking to us!
+		print $debug "STOP\n";
+		exit();
+	}
+	elsif ( $bytes_read != 4 ) {
+		die "invalid packet: '$buffer'";
+	}
+	my $pkt_size = hex($buffer);
+	if ( $pkt_size == 0 ) {
+		return ( 1, "" );
+	}
+	elsif ( $pkt_size > 4 ) {
+		my $content_size = $pkt_size - 4;
+		$bytes_read = read STDIN, $buffer, $content_size;
+		if ( $bytes_read != $content_size ) {
+			die "invalid packet ($content_size bytes expected; $bytes_read bytes read)";
+		}
+		return ( 0, $buffer );
+	}
+	else {
+		die "invalid packet size: $pkt_size";
+	}
+}
+
+sub packet_txt_read {
+	my ( $res, $buf ) = packet_bin_read();
+	unless ( $buf =~ s/\n$// ) {
+		die "A non-binary line MUST be terminated by an LF.";
+	}
+	return ( $res, $buf );
+}
+
+sub packet_bin_write {
+	my $buf = shift;
+	print STDOUT sprintf( "%04x", length($buf) + 4 );
+	print STDOUT $buf;
+	STDOUT->flush();
+}
+
+sub packet_txt_write {
+	packet_bin_write( $_[0] . "\n" );
+}
+
+sub packet_flush {
+	print STDOUT sprintf( "%04x", 0 );
+	STDOUT->flush();
+}
+
+print $debug "START\n";
+$debug->flush();
+
+( packet_txt_read() eq ( 0, "git-filter-client" ) ) || die "bad initialize";
+( packet_txt_read() eq ( 0, "version=2" ) )         || die "bad version";
+( packet_bin_read() eq ( 1, "" ) )                  || die "bad version end";
+
+packet_txt_write("git-filter-server");
+packet_txt_write("version=2");
+packet_flush();
+
+( packet_txt_read() eq ( 0, "capability=clean" ) )  || die "bad capability";
+( packet_txt_read() eq ( 0, "capability=smudge" ) ) || die "bad capability";
+( packet_bin_read() eq ( 1, "" ) )                  || die "bad capability end";
+
+foreach (@capabilities) {
+	packet_txt_write( "capability=" . $_ );
+}
+packet_flush();
+print $debug "init handshake complete\n";
+$debug->flush();
+
+while (1) {
+	my ($command) = packet_txt_read() =~ /^command=([^=]+)$/;
+	print $debug "IN: $command";
+	$debug->flush();
+
+	my ($pathname) = packet_txt_read() =~ /^pathname=([^=]+)$/;
+	print $debug " $pathname";
+	$debug->flush();
+
+	# Flush
+	packet_bin_read();
+
+	my $input = "";
+	{
+		binmode(STDIN);
+		my $buffer;
+		my $done = 0;
+		while ( !$done ) {
+			( $done, $buffer ) = packet_bin_read();
+			$input .= $buffer;
+		}
+		print $debug " " . length($input) . " [OK] -- ";
+		$debug->flush();
+	}
+
+	my $output;
+	if ( $pathname eq "error.r" or $pathname eq "abort.r" ) {
+		$output = "";
+	}
+	elsif ( $command eq "clean" and grep( /^clean$/, @capabilities ) ) {
+		$output = rot13($input);
+	}
+	elsif ( $command eq "smudge" and grep( /^smudge$/, @capabilities ) ) {
+		$output = rot13($input);
+	}
+	else {
+		die "bad command '$command'";
+	}
+
+	print $debug "OUT: " . length($output) . " ";
+	$debug->flush();
+
+	if ( $pathname eq "error.r" ) {
+		print $debug "[ERROR]\n";
+		$debug->flush();
+		packet_txt_write("status=error");
+		packet_flush();
+	}
+	elsif ( $pathname eq "abort.r" ) {
+		print $debug "[ABORT]\n";
+		$debug->flush();
+		packet_txt_write("status=abort");
+		packet_flush();
+	}
+	else {
+		packet_txt_write("status=success");
+		packet_flush();
+
+		if ( $pathname eq "${command}-write-fail.r" ) {
+			print $debug "[WRITE FAIL]\n";
+			$debug->flush();
+			die "${command} write error";
+		}
+
+		while ( length($output) > 0 ) {
+			my $packet = substr( $output, 0, $MAX_PACKET_CONTENT_SIZE );
+			packet_bin_write($packet);
+			# dots represent the number of packets
+			print $debug ".";
+			if ( length($output) > $MAX_PACKET_CONTENT_SIZE ) {
+				$output = substr( $output, $MAX_PACKET_CONTENT_SIZE );
+			}
+			else {
+				$output = "";
+			}
+		}
+		packet_flush();
+		print $debug " [OK]\n";
+		$debug->flush();
+		packet_flush();
+	}
+}
diff --git a/t/t0040-parse-options.sh b/t/t0040-parse-options.sh
index db5f60d0c5..74d2cd76fe 100755
--- a/t/t0040-parse-options.sh
+++ b/t/t0040-parse-options.sh
@@ -208,32 +208,15 @@ test_expect_success 'unambiguously abbreviated option' '
 '
 
 test_expect_success 'unambiguously abbreviated option with "="' '
-	test-parse-options --int=2 >output 2>output.err &&
-	test_must_be_empty output.err &&
-	test_cmp expect output
+	test-parse-options --expect="integer: 2" --int=2
 '
 
 test_expect_success 'ambiguously abbreviated option' '
 	test_expect_code 129 test-parse-options --strin 123
 '
 
-cat >expect <<\EOF
-boolean: 0
-integer: 0
-magnitude: 0
-timestamp: 0
-string: 123
-abbrev: 7
-verbose: -1
-quiet: 0
-dry run: no
-file: (not set)
-EOF
-
 test_expect_success 'non ambiguous option (after two options it abbreviates)' '
-	test-parse-options --st 123 >output 2>output.err &&
-	test_must_be_empty output.err &&
-	test_cmp expect output
+	test-parse-options --expect="string: 123" --st 123
 '
 
 cat >typo.err <<\EOF
@@ -256,24 +239,8 @@ test_expect_success 'detect possible typos' '
 	test_cmp typo.err output.err
 '
 
-cat >expect <<\EOF
-boolean: 0
-integer: 0
-magnitude: 0
-timestamp: 0
-string: (not set)
-abbrev: 7
-verbose: -1
-quiet: 0
-dry run: no
-file: (not set)
-arg 00: --quux
-EOF
-
 test_expect_success 'keep some options as arguments' '
-	test-parse-options --quux >output 2>output.err &&
-	test_must_be_empty output.err &&
-	test_cmp expect output
+	test-parse-options --expect="arg 00: --quux" --quux
 '
 
 cat >expect <<\EOF
@@ -350,54 +317,20 @@ test_expect_success 'OPT_NEGBIT() and OPT_SET_INT() work' '
 	test_cmp expect output
 '
 
-cat >expect <<\EOF
-boolean: 6
-integer: 0
-magnitude: 0
-timestamp: 0
-string: (not set)
-abbrev: 7
-verbose: -1
-quiet: 0
-dry run: no
-file: (not set)
-EOF
-
 test_expect_success 'OPT_BIT() works' '
-	test-parse-options -bb --or4 >output 2>output.err &&
-	test_must_be_empty output.err &&
-	test_cmp expect output
+	test-parse-options --expect="boolean: 6" -bb --or4
 '
 
 test_expect_success 'OPT_NEGBIT() works' '
-	test-parse-options -bb --no-neg-or4 >output 2>output.err &&
-	test_must_be_empty output.err &&
-	test_cmp expect output
+	test-parse-options --expect="boolean: 6" -bb --no-neg-or4
 '
 
 test_expect_success 'OPT_COUNTUP() with PARSE_OPT_NODASH works' '
-	test-parse-options + + + + + + >output 2>output.err &&
-	test_must_be_empty output.err &&
-	test_cmp expect output
+	test-parse-options --expect="boolean: 6" + + + + + +
 '
 
-cat >expect <<\EOF
-boolean: 0
-integer: 12345
-magnitude: 0
-timestamp: 0
-string: (not set)
-abbrev: 7
-verbose: -1
-quiet: 0
-dry run: no
-file: (not set)
-EOF
-
 test_expect_success 'OPT_NUMBER_CALLBACK() works' '
-	test-parse-options -12345 >output 2>output.err &&
-	test_must_be_empty output.err &&
-	test_cmp expect output
+	test-parse-options --expect="integer: 12345" -12345
 '
 
 cat >expect <<\EOF
@@ -435,118 +368,28 @@ test_expect_success '--no-list resets list' '
 	test_cmp expect output
 '
 
-cat >expect <<\EOF
-boolean: 0
-integer: 0
-magnitude: 0
-timestamp: 0
-string: (not set)
-abbrev: 7
-verbose: -1
-quiet: 3
-dry run: no
-file: (not set)
-EOF
-
 test_expect_success 'multiple quiet levels' '
-	test-parse-options -q -q -q >output 2>output.err &&
-	test_must_be_empty output.err &&
-	test_cmp expect output
+	test-parse-options --expect="quiet: 3" -q -q -q
 '
 
-cat >expect <<\EOF
-boolean: 0
-integer: 0
-magnitude: 0
-timestamp: 0
-string: (not set)
-abbrev: 7
-verbose: 3
-quiet: 0
-dry run: no
-file: (not set)
-EOF
-
 test_expect_success 'multiple verbose levels' '
-	test-parse-options -v -v -v >output 2>output.err &&
-	test_must_be_empty output.err &&
-	test_cmp expect output
+	test-parse-options --expect="verbose: 3" -v -v -v
 '
 
-cat >expect <<\EOF
-boolean: 0
-integer: 0
-magnitude: 0
-timestamp: 0
-string: (not set)
-abbrev: 7
-verbose: -1
-quiet: 0
-dry run: no
-file: (not set)
-EOF
-
 test_expect_success '--no-quiet sets --quiet to 0' '
-	test-parse-options --no-quiet >output 2>output.err &&
-	test_must_be_empty output.err &&
-	test_cmp expect output
+	test-parse-options --expect="quiet: 0" --no-quiet
 '
 
-cat >expect <<\EOF
-boolean: 0
-integer: 0
-magnitude: 0
-timestamp: 0
-string: (not set)
-abbrev: 7
-verbose: -1
-quiet: 0
-dry run: no
-file: (not set)
-EOF
-
 test_expect_success '--no-quiet resets multiple -q to 0' '
-	test-parse-options -q -q -q --no-quiet >output 2>output.err &&
-	test_must_be_empty output.err &&
-	test_cmp expect output
+	test-parse-options --expect="quiet: 0" -q -q -q --no-quiet
 '
 
-cat >expect <<\EOF
-boolean: 0
-integer: 0
-magnitude: 0
-timestamp: 0
-string: (not set)
-abbrev: 7
-verbose: 0
-quiet: 0
-dry run: no
-file: (not set)
-EOF
-
 test_expect_success '--no-verbose sets verbose to 0' '
-	test-parse-options --no-verbose >output 2>output.err &&
-	test_must_be_empty output.err &&
-	test_cmp expect output
+	test-parse-options --expect="verbose: 0" --no-verbose
 '
 
-cat >expect <<\EOF
-boolean: 0
-integer: 0
-magnitude: 0
-timestamp: 0
-string: (not set)
-abbrev: 7
-verbose: 0
-quiet: 0
-dry run: no
-file: (not set)
-EOF
-
 test_expect_success '--no-verbose resets multiple verbose to 0' '
-	test-parse-options -v -v -v --no-verbose >output 2>output.err &&
-	test_must_be_empty output.err &&
-	test_cmp expect output
+	test-parse-options --expect="verbose: 0" -v -v -v --no-verbose
 '
 
 test_done
diff --git a/t/t0060-path-utils.sh b/t/t0060-path-utils.sh
index bf2deee109..444b5a4df8 100755
--- a/t/t0060-path-utils.sh
+++ b/t/t0060-path-utils.sh
@@ -305,8 +305,9 @@ test_git_path GIT_COMMON_DIR=bar config                   bar/config
 test_git_path GIT_COMMON_DIR=bar packed-refs              bar/packed-refs
 test_git_path GIT_COMMON_DIR=bar shallow                  bar/shallow
 
-# In the tests below, the distinction between $PWD and $(pwd) is important:
-# on Windows, $PWD is POSIX style (/c/foo), $(pwd) has drive letter (c:/foo).
+# In the tests below, $(pwd) must be used because it is a native path on
+# Windows and avoids MSYS's path mangling (which simplifies "foo/../bar" and
+# strips the dot from trailing "/.").
 
 test_submodule_relative_url "../" "../foo" "../submodule" "../../submodule"
 test_submodule_relative_url "../" "../foo/bar" "../submodule" "../../foo/submodule"
@@ -314,27 +315,29 @@ test_submodule_relative_url "../" "../foo/submodule" "../submodule" "../../foo/s
 test_submodule_relative_url "../" "./foo" "../submodule" "../submodule"
 test_submodule_relative_url "../" "./foo/bar" "../submodule" "../foo/submodule"
 test_submodule_relative_url "../../../" "../foo/bar" "../sub/a/b/c" "../../../../foo/sub/a/b/c"
-test_submodule_relative_url "../" "$PWD/addtest" "../repo" "$(pwd)/repo"
+test_submodule_relative_url "../" "$(pwd)/addtest" "../repo" "$(pwd)/repo"
 test_submodule_relative_url "../" "foo/bar" "../submodule" "../foo/submodule"
 test_submodule_relative_url "../" "foo" "../submodule" "../submodule"
 
 test_submodule_relative_url "(null)" "../foo/bar" "../sub/a/b/c" "../foo/sub/a/b/c"
+test_submodule_relative_url "(null)" "../foo/bar" "../sub/a/b/c/" "../foo/sub/a/b/c"
+test_submodule_relative_url "(null)" "../foo/bar/" "../sub/a/b/c" "../foo/sub/a/b/c"
 test_submodule_relative_url "(null)" "../foo/bar" "../submodule" "../foo/submodule"
 test_submodule_relative_url "(null)" "../foo/submodule" "../submodule" "../foo/submodule"
 test_submodule_relative_url "(null)" "../foo" "../submodule" "../submodule"
 test_submodule_relative_url "(null)" "./foo/bar" "../submodule" "foo/submodule"
 test_submodule_relative_url "(null)" "./foo" "../submodule" "submodule"
 test_submodule_relative_url "(null)" "//somewhere else/repo" "../subrepo" "//somewhere else/subrepo"
-test_submodule_relative_url "(null)" "$PWD/subsuper_update_r" "../subsubsuper_update_r" "$(pwd)/subsubsuper_update_r"
-test_submodule_relative_url "(null)" "$PWD/super_update_r2" "../subsuper_update_r" "$(pwd)/subsuper_update_r"
-test_submodule_relative_url "(null)" "$PWD/." "../." "$(pwd)/."
-test_submodule_relative_url "(null)" "$PWD" "./." "$(pwd)/."
-test_submodule_relative_url "(null)" "$PWD/addtest" "../repo" "$(pwd)/repo"
-test_submodule_relative_url "(null)" "$PWD" "./å äö" "$(pwd)/å äö"
-test_submodule_relative_url "(null)" "$PWD/." "../submodule" "$(pwd)/submodule"
-test_submodule_relative_url "(null)" "$PWD/submodule" "../submodule" "$(pwd)/submodule"
-test_submodule_relative_url "(null)" "$PWD/home2/../remote" "../bundle1" "$(pwd)/home2/../bundle1"
-test_submodule_relative_url "(null)" "$PWD/submodule_update_repo" "./." "$(pwd)/submodule_update_repo/."
+test_submodule_relative_url "(null)" "$(pwd)/subsuper_update_r" "../subsubsuper_update_r" "$(pwd)/subsubsuper_update_r"
+test_submodule_relative_url "(null)" "$(pwd)/super_update_r2" "../subsuper_update_r" "$(pwd)/subsuper_update_r"
+test_submodule_relative_url "(null)" "$(pwd)/." "../." "$(pwd)/."
+test_submodule_relative_url "(null)" "$(pwd)" "./." "$(pwd)/."
+test_submodule_relative_url "(null)" "$(pwd)/addtest" "../repo" "$(pwd)/repo"
+test_submodule_relative_url "(null)" "$(pwd)" "./å äö" "$(pwd)/å äö"
+test_submodule_relative_url "(null)" "$(pwd)/." "../submodule" "$(pwd)/submodule"
+test_submodule_relative_url "(null)" "$(pwd)/submodule" "../submodule" "$(pwd)/submodule"
+test_submodule_relative_url "(null)" "$(pwd)/home2/../remote" "../bundle1" "$(pwd)/home2/../bundle1"
+test_submodule_relative_url "(null)" "$(pwd)/submodule_update_repo" "./." "$(pwd)/submodule_update_repo/."
 test_submodule_relative_url "(null)" "file:///tmp/repo" "../subrepo" "file:///tmp/subrepo"
 test_submodule_relative_url "(null)" "foo/bar" "../submodule" "foo/submodule"
 test_submodule_relative_url "(null)" "foo" "../submodule" "submodule"
diff --git a/t/t1512-rev-parse-disambiguation.sh b/t/t1512-rev-parse-disambiguation.sh
index 7c659eb585..711704ba5a 100755
--- a/t/t1512-rev-parse-disambiguation.sh
+++ b/t/t1512-rev-parse-disambiguation.sh
@@ -42,7 +42,7 @@ test_expect_success 'blob and tree' '
 
 test_expect_success 'warn ambiguity when no candidate matches type hint' '
 	test_must_fail git rev-parse --verify 000000000^{commit} 2>actual &&
-	grep "short SHA1 000000000 is ambiguous" actual
+	test_i18ngrep "short SHA1 000000000 is ambiguous" actual
 '
 
 test_expect_success 'disambiguate tree-ish' '
diff --git a/t/t2025-worktree-add.sh b/t/t2025-worktree-add.sh
index 4bcc335a19..b618d6be21 100755
--- a/t/t2025-worktree-add.sh
+++ b/t/t2025-worktree-add.sh
@@ -138,6 +138,14 @@ test_expect_success 'checkout from a bare repo without "add"' '
 	)
 '
 
+test_expect_success '"add" default branch of a bare repo' '
+	(
+		git clone --bare . bare2 &&
+		cd bare2 &&
+		git worktree add ../there3 master
+	)
+'
+
 test_expect_success 'checkout with grafts' '
 	test_when_finished rm .git/info/grafts &&
 	test_commit abc &&
diff --git a/t/t2203-add-intent.sh b/t/t2203-add-intent.sh
index 8f22c43e24..84a9028c43 100755
--- a/t/t2203-add-intent.sh
+++ b/t/t2203-add-intent.sh
@@ -5,10 +5,24 @@ test_description='Intent to add'
 . ./test-lib.sh
 
 test_expect_success 'intent to add' '
+	test_commit 1 &&
+	git rm 1.t &&
+	echo hello >1.t &&
 	echo hello >file &&
 	echo hello >elif &&
 	git add -N file &&
-	git add elif
+	git add elif &&
+	git add -N 1.t
+'
+
+test_expect_success 'git status' '
+	git status --porcelain | grep -v actual >actual &&
+	cat >expect <<-\EOF &&
+	DA 1.t
+	A  elif
+	 A file
+	EOF
+	test_cmp expect actual
 '
 
 test_expect_success 'check result of "add -N"' '
@@ -43,7 +57,9 @@ test_expect_success 'i-t-a entry is simply ignored' '
 	git add -N nitfol &&
 	git commit -m second &&
 	test $(git ls-tree HEAD -- nitfol | wc -l) = 0 &&
-	test $(git diff --name-only HEAD -- nitfol | wc -l) = 1
+	test $(git diff --name-only HEAD -- nitfol | wc -l) = 1 &&
+	test $(git diff --name-only --ita-invisible-in-index HEAD -- nitfol | wc -l) = 0 &&
+	test $(git diff --name-only --ita-invisible-in-index -- nitfol | wc -l) = 1
 '
 
 test_expect_success 'can commit with an unrelated i-t-a entry in index' '
@@ -113,5 +129,26 @@ test_expect_success 'cache-tree does skip dir that becomes empty' '
 	)
 '
 
+test_expect_success 'commit: ita entries ignored in empty intial commit check' '
+	git init empty-intial-commit &&
+	(
+		cd empty-intial-commit &&
+		: >one &&
+		git add -N one &&
+		test_must_fail git commit -m nothing-new-here
+	)
+'
+
+test_expect_success 'commit: ita entries ignored in empty commit check' '
+	git init empty-subsequent-commit &&
+	(
+		cd empty-subsequent-commit &&
+		test_commit one &&
+		: >two &&
+		git add -N two &&
+		test_must_fail git commit -m nothing-new-here
+	)
+'
+
 test_done
 
diff --git a/t/t3007-ls-files-recurse-submodules.sh b/t/t3007-ls-files-recurse-submodules.sh
new file mode 100755
index 0000000000..a5426171d3
--- /dev/null
+++ b/t/t3007-ls-files-recurse-submodules.sh
@@ -0,0 +1,210 @@
+#!/bin/sh
+
+test_description='Test ls-files recurse-submodules feature
+
+This test verifies the recurse-submodules feature correctly lists files from
+submodules.
+'
+
+. ./test-lib.sh
+
+test_expect_success 'setup directory structure and submodules' '
+	echo a >a &&
+	mkdir b &&
+	echo b >b/b &&
+	git add a b &&
+	git commit -m "add a and b" &&
+	git init submodule &&
+	echo c >submodule/c &&
+	git -C submodule add c &&
+	git -C submodule commit -m "add c" &&
+	git submodule add ./submodule &&
+	git commit -m "added submodule"
+'
+
+test_expect_success 'ls-files correctly outputs files in submodule' '
+	cat >expect <<-\EOF &&
+	.gitmodules
+	a
+	b/b
+	submodule/c
+	EOF
+
+	git ls-files --recurse-submodules >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'ls-files correctly outputs files in submodule with -z' '
+	lf_to_nul >expect <<-\EOF &&
+	.gitmodules
+	a
+	b/b
+	submodule/c
+	EOF
+
+	git ls-files --recurse-submodules -z >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'ls-files does not output files not added to a repo' '
+	cat >expect <<-\EOF &&
+	.gitmodules
+	a
+	b/b
+	submodule/c
+	EOF
+
+	echo a >not_added &&
+	echo b >b/not_added &&
+	echo c >submodule/not_added &&
+	git ls-files --recurse-submodules >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'ls-files recurses more than 1 level' '
+	cat >expect <<-\EOF &&
+	.gitmodules
+	a
+	b/b
+	submodule/.gitmodules
+	submodule/c
+	submodule/subsub/d
+	EOF
+
+	git init submodule/subsub &&
+	echo d >submodule/subsub/d &&
+	git -C submodule/subsub add d &&
+	git -C submodule/subsub commit -m "add d" &&
+	git -C submodule submodule add ./subsub &&
+	git -C submodule commit -m "added subsub" &&
+	git ls-files --recurse-submodules >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--recurse-submodules and pathspecs setup' '
+	echo e >submodule/subsub/e.txt &&
+	git -C submodule/subsub add e.txt &&
+	git -C submodule/subsub commit -m "adding e.txt" &&
+	echo f >submodule/f.TXT &&
+	echo g >submodule/g.txt &&
+	git -C submodule add f.TXT g.txt &&
+	git -C submodule commit -m "add f and g" &&
+	echo h >h.txt &&
+	mkdir sib &&
+	echo sib >sib/file &&
+	git add h.txt sib/file &&
+	git commit -m "add h and sib/file" &&
+	git init sub &&
+	echo sub >sub/file &&
+	git -C sub add file &&
+	git -C sub commit -m "add file" &&
+	git submodule add ./sub &&
+	git commit -m "added sub" &&
+
+	cat >expect <<-\EOF &&
+	.gitmodules
+	a
+	b/b
+	h.txt
+	sib/file
+	sub/file
+	submodule/.gitmodules
+	submodule/c
+	submodule/f.TXT
+	submodule/g.txt
+	submodule/subsub/d
+	submodule/subsub/e.txt
+	EOF
+
+	git ls-files --recurse-submodules >actual &&
+	test_cmp expect actual &&
+	cat actual &&
+	git ls-files --recurse-submodules "*" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--recurse-submodules and pathspecs' '
+	cat >expect <<-\EOF &&
+	h.txt
+	submodule/g.txt
+	submodule/subsub/e.txt
+	EOF
+
+	git ls-files --recurse-submodules "*.txt" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--recurse-submodules and pathspecs' '
+	cat >expect <<-\EOF &&
+	h.txt
+	submodule/f.TXT
+	submodule/g.txt
+	submodule/subsub/e.txt
+	EOF
+
+	git ls-files --recurse-submodules ":(icase)*.txt" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--recurse-submodules and pathspecs' '
+	cat >expect <<-\EOF &&
+	h.txt
+	submodule/f.TXT
+	submodule/g.txt
+	EOF
+
+	git ls-files --recurse-submodules ":(icase)*.txt" ":(exclude)submodule/subsub/*" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--recurse-submodules and pathspecs' '
+	cat >expect <<-\EOF &&
+	sub/file
+	EOF
+
+	git ls-files --recurse-submodules "sub" >actual &&
+	test_cmp expect actual &&
+	git ls-files --recurse-submodules "sub/" >actual &&
+	test_cmp expect actual &&
+	git ls-files --recurse-submodules "sub/file" >actual &&
+	test_cmp expect actual &&
+	git ls-files --recurse-submodules "su*/file" >actual &&
+	test_cmp expect actual &&
+	git ls-files --recurse-submodules "su?/file" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--recurse-submodules and pathspecs' '
+	cat >expect <<-\EOF &&
+	sib/file
+	sub/file
+	EOF
+
+	git ls-files --recurse-submodules "s??/file" >actual &&
+	test_cmp expect actual &&
+	git ls-files --recurse-submodules "s???file" >actual &&
+	test_cmp expect actual &&
+	git ls-files --recurse-submodules "s*file" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--recurse-submodules does not support --error-unmatch' '
+	test_must_fail git ls-files --recurse-submodules --error-unmatch 2>actual &&
+	test_i18ngrep "does not support --error-unmatch" actual
+'
+
+test_incompatible_with_recurse_submodules () {
+	test_expect_success "--recurse-submodules and $1 are incompatible" "
+		test_must_fail git ls-files --recurse-submodules $1 2>actual &&
+		test_i18ngrep 'unsupported mode' actual
+	"
+}
+
+test_incompatible_with_recurse_submodules --deleted
+test_incompatible_with_recurse_submodules --modified
+test_incompatible_with_recurse_submodules --others
+test_incompatible_with_recurse_submodules --stage
+test_incompatible_with_recurse_submodules --killed
+test_incompatible_with_recurse_submodules --unmerged
+
+test_done
diff --git a/t/t3501-revert-cherry-pick.sh b/t/t3501-revert-cherry-pick.sh
index 51f3bbb8af..394f0005a1 100755
--- a/t/t3501-revert-cherry-pick.sh
+++ b/t/t3501-revert-cherry-pick.sh
@@ -96,7 +96,7 @@ test_expect_success 'revert forbidden on dirty working tree' '
 	echo content >extra_file &&
 	git add extra_file &&
 	test_must_fail git revert HEAD 2>errors &&
-	test_i18ngrep "Your local changes would be overwritten by " errors
+	test_i18ngrep "your local changes would be overwritten by " errors
 
 '
 
diff --git a/t/t3600-rm.sh b/t/t3600-rm.sh
index d046d98aec..14f0edca2b 100755
--- a/t/t3600-rm.sh
+++ b/t/t3600-rm.sh
@@ -881,4 +881,9 @@ test_expect_success 'rm files with two different errors' '
 	test_i18ncmp expect actual
 '
 
+test_expect_success 'rm empty string should invoke warning' '
+	git rm -rf "" 2>output &&
+	test_i18ngrep "warning: empty strings" output
+'
+
 test_done
diff --git a/t/t3700-add.sh b/t/t3700-add.sh
index 924a266126..f3a4b4a913 100755
--- a/t/t3700-add.sh
+++ b/t/t3700-add.sh
@@ -331,6 +331,11 @@ test_expect_success 'git add --dry-run --ignore-missing of non-existing file out
 	test_i18ncmp expect.err actual.err
 '
 
+test_expect_success 'git add empty string should invoke warning' '
+	git add "" 2>output &&
+	test_i18ngrep "warning: empty strings" output
+'
+
 test_expect_success 'git add --chmod=[+-]x stages correctly' '
 	rm -f foo1 &&
 	echo foo >foo1 &&
@@ -350,6 +355,7 @@ test_expect_success POSIXPERM,SYMLINKS 'git add --chmod=+x with symlinks' '
 '
 
 test_expect_success 'git add --chmod=[+-]x changes index with already added file' '
+	rm -f foo3 xfoo3 &&
 	echo foo >foo3 &&
 	git add foo3 &&
 	git add --chmod=+x foo3 &&
diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh
index 2434157aa7..289806d0c7 100755
--- a/t/t4015-diff-whitespace.sh
+++ b/t/t4015-diff-whitespace.sh
@@ -869,7 +869,8 @@ test_expect_success 'diff that introduces and removes ws breakages' '
 	test_cmp expected current
 '
 
-test_expect_success 'the same with --ws-error-highlight' '
+test_expect_success 'ws-error-highlight test setup' '
+
 	git reset --hard &&
 	{
 		echo "0. blank-at-eol " &&
@@ -882,10 +883,7 @@ test_expect_success 'the same with --ws-error-highlight' '
 		echo "2. and a new line "
 	} >x &&
 
-	git -c color.diff=always diff --ws-error-highlight=default,old |
-	test_decode_color >current &&
-
-	cat >expected <<-\EOF &&
+	cat >expect.default-old <<-\EOF &&
 	<BOLD>diff --git a/x b/x<RESET>
 	<BOLD>index d0233a2..700886e 100644<RESET>
 	<BOLD>--- a/x<RESET>
@@ -897,12 +895,7 @@ test_expect_success 'the same with --ws-error-highlight' '
 	<GREEN>+<RESET><GREEN>2. and a new line<RESET><BLUE> <RESET>
 	EOF
 
-	test_cmp expected current &&
-
-	git -c color.diff=always diff --ws-error-highlight=all |
-	test_decode_color >current &&
-
-	cat >expected <<-\EOF &&
+	cat >expect.all <<-\EOF &&
 	<BOLD>diff --git a/x b/x<RESET>
 	<BOLD>index d0233a2..700886e 100644<RESET>
 	<BOLD>--- a/x<RESET>
@@ -914,12 +907,7 @@ test_expect_success 'the same with --ws-error-highlight' '
 	<GREEN>+<RESET><GREEN>2. and a new line<RESET><BLUE> <RESET>
 	EOF
 
-	test_cmp expected current &&
-
-	git -c color.diff=always diff --ws-error-highlight=none |
-	test_decode_color >current &&
-
-	cat >expected <<-\EOF &&
+	cat >expect.none <<-\EOF
 	<BOLD>diff --git a/x b/x<RESET>
 	<BOLD>index d0233a2..700886e 100644<RESET>
 	<BOLD>--- a/x<RESET>
@@ -931,7 +919,57 @@ test_expect_success 'the same with --ws-error-highlight' '
 	<GREEN>+2. and a new line <RESET>
 	EOF
 
-	test_cmp expected current
+'
+
+test_expect_success 'test --ws-error-highlight option' '
+
+	git -c color.diff=always diff --ws-error-highlight=default,old |
+	test_decode_color >current &&
+	test_cmp expect.default-old current &&
+
+	git -c color.diff=always diff --ws-error-highlight=all |
+	test_decode_color >current &&
+	test_cmp expect.all current &&
+
+	git -c color.diff=always diff --ws-error-highlight=none |
+	test_decode_color >current &&
+	test_cmp expect.none current
+
+'
+
+test_expect_success 'test diff.wsErrorHighlight config' '
+
+	git -c color.diff=always -c diff.wsErrorHighlight=default,old diff |
+	test_decode_color >current &&
+	test_cmp expect.default-old current &&
+
+	git -c color.diff=always -c diff.wsErrorHighlight=all diff |
+	test_decode_color >current &&
+	test_cmp expect.all current &&
+
+	git -c color.diff=always -c diff.wsErrorHighlight=none diff |
+	test_decode_color >current &&
+	test_cmp expect.none current
+
+'
+
+test_expect_success 'option overrides diff.wsErrorHighlight' '
+
+	git -c color.diff=always -c diff.wsErrorHighlight=none \
+		diff --ws-error-highlight=default,old |
+	test_decode_color >current &&
+	test_cmp expect.default-old current &&
+
+	git -c color.diff=always -c diff.wsErrorHighlight=default \
+		diff --ws-error-highlight=all |
+	test_decode_color >current &&
+	test_cmp expect.all current &&
+
+	git -c color.diff=always -c diff.wsErrorHighlight=all \
+		diff --ws-error-highlight=none |
+	test_decode_color >current &&
+	test_cmp expect.none current
+
 '
 
 test_done
diff --git a/t/t4254-am-corrupt.sh b/t/t4254-am-corrupt.sh
index 9bd7dd2ba1..168739c721 100755
--- a/t/t4254-am-corrupt.sh
+++ b/t/t4254-am-corrupt.sh
@@ -31,7 +31,7 @@ test_expect_success 'try to apply corrupted patch' '
 test_expect_success 'compare diagnostic; ensure file is still here' '
 	echo "error: git diff header lacks filename information (line 4)" >expected &&
 	test_path_is_file f &&
-	test_cmp expected actual
+	test_i18ncmp expected actual
 '
 
 test_done
diff --git a/t/t6000-rev-list-misc.sh b/t/t6000-rev-list-misc.sh
index 3e752ce032..969e4e9e52 100755
--- a/t/t6000-rev-list-misc.sh
+++ b/t/t6000-rev-list-misc.sh
@@ -100,4 +100,18 @@ test_expect_success '--bisect and --first-parent can not be combined' '
 	test_must_fail git rev-list --bisect --first-parent HEAD
 '
 
+test_expect_success '--header shows a NUL after each commit' '
+	# We know that there is no Q in the true payload; names and
+	# addresses of the authors and the committers do not have
+	# any, and object names or header names do not, either.
+	git rev-list --header --max-count=2 HEAD |
+	nul_to_q |
+	grep "^Q" >actual &&
+	cat >expect <<-EOF &&
+	Q$(git rev-parse HEAD~1)
+	Q
+	EOF
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t6010-merge-base.sh b/t/t6010-merge-base.sh
index e0c5f44cac..31db7b5f91 100755
--- a/t/t6010-merge-base.sh
+++ b/t/t6010-merge-base.sh
@@ -260,6 +260,12 @@ test_expect_success 'using reflog to find the fork point' '
 	test_cmp expect3 actual
 '
 
+test_expect_success '--fork-point works with empty reflog' '
+	git -c core.logallrefupdates=false branch no-reflog base &&
+	git merge-base --fork-point no-reflog derived &&
+	test_cmp expect3 actual
+'
+
 test_expect_success 'merge-base --octopus --all for complex tree' '
 	# Best common ancestor for JE, JAA and JDD is JC
 	#             JE
diff --git a/t/t7064-wtstatus-pv2.sh b/t/t7064-wtstatus-pv2.sh
index 3012a4d7c0..e319fa2e84 100755
--- a/t/t7064-wtstatus-pv2.sh
+++ b/t/t7064-wtstatus-pv2.sh
@@ -246,8 +246,8 @@ test_expect_success 'verify --intent-to-add output' '
 	git add --intent-to-add intent1.add intent2.add &&
 
 	cat >expect <<-EOF &&
-	1 AM N... 000000 100644 100644 $_z40 $EMPTY_BLOB intent1.add
-	1 AM N... 000000 100644 100644 $_z40 $EMPTY_BLOB intent2.add
+	1 .A N... 000000 000000 100644 $_z40 $_z40 intent1.add
+	1 .A N... 000000 000000 100644 $_z40 $_z40 intent2.add
 	EOF
 
 	git status --porcelain=v2 >actual &&
diff --git a/t/t7510-signed-commit.sh b/t/t7510-signed-commit.sh
index 6e839f5489..762135adea 100755
--- a/t/t7510-signed-commit.sh
+++ b/t/t7510-signed-commit.sh
@@ -2,6 +2,7 @@
 
 test_description='signed commit tests'
 . ./test-lib.sh
+GNUPGHOME_NOT_USED=$GNUPGHOME
 . "$TEST_DIRECTORY/lib-gpg.sh"
 
 test_expect_success GPG 'create signed commits' '
@@ -190,7 +191,7 @@ test_expect_success GPG 'show bad signature with custom format' '
 	test_cmp expect actual
 '
 
-test_expect_success GPG 'show unknown signature with custom format' '
+test_expect_success GPG 'show untrusted signature with custom format' '
 	cat >expect <<-\EOF &&
 	U
 	61092E85B7227189
@@ -200,6 +201,16 @@ test_expect_success GPG 'show unknown signature with custom format' '
 	test_cmp expect actual
 '
 
+test_expect_success GPG 'show unknown signature with custom format' '
+	cat >expect <<-\EOF &&
+	E
+	61092E85B7227189
+
+	EOF
+	GNUPGHOME="$GNUPGHOME_NOT_USED" git log -1 --format="%G?%n%GK%n%GS" eighth-signed-alt >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success GPG 'show lack of signature with custom format' '
 	cat >expect <<-\EOF &&
 	N
diff --git a/t/t7513-interpret-trailers.sh b/t/t7513-interpret-trailers.sh
index aee785cffa..4dd1d7c520 100755
--- a/t/t7513-interpret-trailers.sh
+++ b/t/t7513-interpret-trailers.sh
@@ -126,6 +126,305 @@ test_expect_success 'with multiline title in the message' '
 	test_cmp expected actual
 '
 
+test_expect_success 'with non-trailer lines mixed with Signed-off-by' '
+	cat >patch <<-\EOF &&
+
+		this is not a trailer
+		this is not a trailer
+		Signed-off-by: a <a@example.com>
+		this is not a trailer
+	EOF
+	cat >expected <<-\EOF &&
+
+		this is not a trailer
+		this is not a trailer
+		Signed-off-by: a <a@example.com>
+		this is not a trailer
+		token: value
+	EOF
+	git interpret-trailers --trailer "token: value" patch >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'with non-trailer lines mixed with cherry picked from' '
+	cat >patch <<-\EOF &&
+
+		this is not a trailer
+		this is not a trailer
+		(cherry picked from commit x)
+		this is not a trailer
+	EOF
+	cat >expected <<-\EOF &&
+
+		this is not a trailer
+		this is not a trailer
+		(cherry picked from commit x)
+		this is not a trailer
+		token: value
+	EOF
+	git interpret-trailers --trailer "token: value" patch >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'with non-trailer lines mixed with a configured trailer' '
+	cat >patch <<-\EOF &&
+
+		this is not a trailer
+		this is not a trailer
+		My-trailer: x
+		this is not a trailer
+	EOF
+	cat >expected <<-\EOF &&
+
+		this is not a trailer
+		this is not a trailer
+		My-trailer: x
+		this is not a trailer
+		token: value
+	EOF
+	test_config trailer.my.key "My-trailer: " &&
+	git interpret-trailers --trailer "token: value" patch >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'with non-trailer lines mixed with a non-configured trailer' '
+	cat >patch <<-\EOF &&
+
+		this is not a trailer
+		this is not a trailer
+		I-am-not-configured: x
+		this is not a trailer
+	EOF
+	cat >expected <<-\EOF &&
+
+		this is not a trailer
+		this is not a trailer
+		I-am-not-configured: x
+		this is not a trailer
+
+		token: value
+	EOF
+	test_config trailer.my.key "My-trailer: " &&
+	git interpret-trailers --trailer "token: value" patch >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'with all non-configured trailers' '
+	cat >patch <<-\EOF &&
+
+		I-am-not-configured: x
+		I-am-also-not-configured: x
+	EOF
+	cat >expected <<-\EOF &&
+
+		I-am-not-configured: x
+		I-am-also-not-configured: x
+		token: value
+	EOF
+	test_config trailer.my.key "My-trailer: " &&
+	git interpret-trailers --trailer "token: value" patch >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'with non-trailer lines only' '
+	cat >patch <<-\EOF &&
+
+		this is not a trailer
+	EOF
+	cat >expected <<-\EOF &&
+
+		this is not a trailer
+
+		token: value
+	EOF
+	git interpret-trailers --trailer "token: value" patch >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'line with leading whitespace is not trailer' '
+	q_to_tab >patch <<-\EOF &&
+
+		Qtoken: value
+	EOF
+	q_to_tab >expected <<-\EOF &&
+
+		Qtoken: value
+
+		token: value
+	EOF
+	git interpret-trailers --trailer "token: value" patch >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'multiline field treated as one trailer for 25% check' '
+	q_to_tab >patch <<-\EOF &&
+
+		Signed-off-by: a <a@example.com>
+		name: value on
+		Qmultiple lines
+		this is not a trailer
+		this is not a trailer
+		this is not a trailer
+		this is not a trailer
+		this is not a trailer
+		this is not a trailer
+	EOF
+	q_to_tab >expected <<-\EOF &&
+
+		Signed-off-by: a <a@example.com>
+		name: value on
+		Qmultiple lines
+		this is not a trailer
+		this is not a trailer
+		this is not a trailer
+		this is not a trailer
+		this is not a trailer
+		this is not a trailer
+		name: value
+	EOF
+	git interpret-trailers --trailer "name: value" patch >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'multiline field treated as atomic for placement' '
+	q_to_tab >patch <<-\EOF &&
+
+		another: trailer
+		name: value on
+		Qmultiple lines
+		another: trailer
+	EOF
+	q_to_tab >expected <<-\EOF &&
+
+		another: trailer
+		name: value on
+		Qmultiple lines
+		name: value
+		another: trailer
+	EOF
+	test_config trailer.name.where after &&
+	git interpret-trailers --trailer "name: value" patch >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'multiline field treated as atomic for replacement' '
+	q_to_tab >patch <<-\EOF &&
+
+		another: trailer
+		name: value on
+		Qmultiple lines
+		another: trailer
+	EOF
+	q_to_tab >expected <<-\EOF &&
+
+		another: trailer
+		another: trailer
+		name: value
+	EOF
+	test_config trailer.name.ifexists replace &&
+	git interpret-trailers --trailer "name: value" patch >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'multiline field treated as atomic for difference check' '
+	q_to_tab >patch <<-\EOF &&
+
+		another: trailer
+		name: first line
+		Qsecond line
+		another: trailer
+	EOF
+	test_config trailer.name.ifexists addIfDifferent &&
+
+	q_to_tab >trailer <<-\EOF &&
+		name: first line
+		Qsecond line
+	EOF
+	q_to_tab >expected <<-\EOF &&
+
+		another: trailer
+		name: first line
+		Qsecond line
+		another: trailer
+	EOF
+	git interpret-trailers --trailer "$(cat trailer)" patch >actual &&
+	test_cmp expected actual &&
+
+	q_to_tab >trailer <<-\EOF &&
+		name: first line
+		QQQQQsecond line
+	EOF
+	q_to_tab >expected <<-\EOF &&
+
+		another: trailer
+		name: first line
+		Qsecond line
+		another: trailer
+		name: first line
+		QQQQQsecond line
+	EOF
+	git interpret-trailers --trailer "$(cat trailer)" patch >actual &&
+	test_cmp expected actual &&
+
+	q_to_tab >trailer <<-\EOF &&
+		name: first line *DIFFERENT*
+		Qsecond line
+	EOF
+	q_to_tab >expected <<-\EOF &&
+
+		another: trailer
+		name: first line
+		Qsecond line
+		another: trailer
+		name: first line *DIFFERENT*
+		Qsecond line
+	EOF
+	git interpret-trailers --trailer "$(cat trailer)" patch >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'multiline field treated as atomic for neighbor check' '
+	q_to_tab >patch <<-\EOF &&
+
+		another: trailer
+		name: first line
+		Qsecond line
+		another: trailer
+	EOF
+	test_config trailer.name.where after &&
+	test_config trailer.name.ifexists addIfDifferentNeighbor &&
+
+	q_to_tab >trailer <<-\EOF &&
+		name: first line
+		Qsecond line
+	EOF
+	q_to_tab >expected <<-\EOF &&
+
+		another: trailer
+		name: first line
+		Qsecond line
+		another: trailer
+	EOF
+	git interpret-trailers --trailer "$(cat trailer)" patch >actual &&
+	test_cmp expected actual &&
+
+	q_to_tab >trailer <<-\EOF &&
+		name: first line
+		QQQQQsecond line
+	EOF
+	q_to_tab >expected <<-\EOF &&
+
+		another: trailer
+		name: first line
+		Qsecond line
+		name: first line
+		QQQQQsecond line
+		another: trailer
+	EOF
+	git interpret-trailers --trailer "$(cat trailer)" patch >actual &&
+	test_cmp expected actual
+'
+
 test_expect_success 'with config setup' '
 	git config trailer.ack.key "Acked-by: " &&
 	cat >expected <<-\EOF &&
diff --git a/t/t9000/test.pl b/t/t9000/test.pl
index 2d05d3eeab..dfeaa9c655 100755
--- a/t/t9000/test.pl
+++ b/t/t9000/test.pl
@@ -32,15 +32,15 @@ my @success_list = (q[Jane],
 	q["Jane\" Doe" <jdoe@example.com>],
 	q[Doe, jane <jdoe@example.com>],
 	q["Jane Doe <jdoe@example.com>],
-	q['Jane 'Doe' <jdoe@example.com>]);
+	q['Jane 'Doe' <jdoe@example.com>],
+	q[Jane@:;\.,()<>Doe <jdoe@example.com>],
+	q[Jane <jdoe@example.com> Doe],
+	q[<jdoe@example.com> Jane Doe]);
 
 my @known_failure_list = (q[Jane\ Doe <jdoe@example.com>],
 	q["Doe, Ja"ne <jdoe@example.com>],
 	q["Doe, Katarina" Jane <jdoe@example.com>],
-	q[Jane@:;\.,()<>Doe <jdoe@example.com>],
 	q[Jane jdoe@example.com],
-	q[<jdoe@example.com> Jane Doe],
-	q[Jane <jdoe@example.com> Doe],
 	q["Jane "Kat"a" ri"na" ",Doe" <jdoe@example.com>],
 	q[Jane Doe],
 	q[Jane "Doe <jdoe@example.com>"],
diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
index b3355d2c70..3dc4a3454d 100755
--- a/t/t9001-send-email.sh
+++ b/t/t9001-send-email.sh
@@ -140,6 +140,35 @@ test_expect_success $PREREQ 'Verify commandline' '
 	test_cmp expected commandline1
 '
 
+test_expect_success $PREREQ 'setup expect for cc trailer' "
+cat >expected-cc <<\EOF
+!recipient@example.com!
+!author@example.com!
+!one@example.com!
+!two@example.com!
+!three@example.com!
+!four@example.com!
+!five@example.com!
+EOF
+"
+
+test_expect_success $PREREQ 'cc trailer with various syntax' '
+	test_commit cc-trailer &&
+	test_when_finished "git reset --hard HEAD^" &&
+	git commit --amend -F - <<-EOF &&
+	Test Cc: trailers.
+
+	Cc: one@example.com
+	Cc: <two@example.com> # this is part of the name
+	Cc: <three@example.com>, <four@example.com> # not.five@example.com
+	Cc: "Some # Body" <five@example.com> [part.of.name.too]
+	EOF
+	clean_fake_sendmail &&
+	git send-email -1 --to=recipient@example.com \
+		--smtp-server="$(pwd)/fake.sendmail" &&
+	test_cmp expected-cc commandline1
+'
+
 test_expect_success $PREREQ 'setup expect' "
 cat >expected-show-all-headers <<\EOF
 0001-Second.patch
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 11562bde10..b859db61ac 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -54,12 +54,22 @@ case "$GIT_TEST_TEE_STARTED, $* " in
 done,*)
 	# do not redirect again
 	;;
-*' --tee '*|*' --va'*)
+*' --tee '*|*' --va'*|*' --verbose-log '*)
 	mkdir -p "$TEST_OUTPUT_DIRECTORY/test-results"
 	BASE="$TEST_OUTPUT_DIRECTORY/test-results/$(basename "$0" .sh)"
+
+	# Make this filename available to the sub-process in case it is using
+	# --verbose-log.
+	GIT_TEST_TEE_OUTPUT_FILE=$BASE.out
+	export GIT_TEST_TEE_OUTPUT_FILE
+
+	# Truncate before calling "tee -a" to get rid of the results
+	# from any previous runs.
+	>"$GIT_TEST_TEE_OUTPUT_FILE"
+
 	(GIT_TEST_TEE_STARTED=done ${SHELL_PATH} "$0" "$@" 2>&1;
-	 echo $? > $BASE.exit) | tee $BASE.out
-	test "$(cat $BASE.exit)" = 0
+	 echo $? >"$BASE.exit") | tee -a "$GIT_TEST_TEE_OUTPUT_FILE"
+	test "$(cat "$BASE.exit")" = 0
 	exit
 	;;
 esac
@@ -246,6 +256,9 @@ do
 		trace=t
 		verbose=t
 		shift ;;
+	--verbose-log)
+		verbose_log=t
+		shift ;;
 	*)
 		echo "error: unknown test option '$1'" >&2; exit 1 ;;
 	esac
@@ -308,6 +321,16 @@ say () {
 	say_color info "$*"
 }
 
+if test -n "$HARNESS_ACTIVE"
+then
+	if test "$verbose" = t || test -n "$verbose_only"
+	then
+		printf 'Bail out! %s\n' \
+		 'verbose mode forbidden under TAP harness; try --verbose-log'
+		exit 1
+	fi
+fi
+
 test "${test_description}" != "" ||
 error "Test script did not set test_description."
 
@@ -319,7 +342,10 @@ fi
 
 exec 5>&1
 exec 6<&0
-if test "$verbose" = "t"
+if test "$verbose_log" = "t"
+then
+	exec 3>>"$GIT_TEST_TEE_OUTPUT_FILE" 4>&3
+elif test "$verbose" = "t"
 then
 	exec 4>&2 3>&1
 else