Merge branch 'ab/mailmap'

Clean-up docs, codepaths and tests around mailmap.

* ab/mailmap: (22 commits)
  shortlog: remove unused(?) "repo-abbrev" feature
  mailmap doc + tests: document and test for case-insensitivity
  mailmap tests: add tests for empty "<>" syntax
  mailmap tests: add tests for whitespace syntax
  mailmap tests: add a test for comment syntax
  mailmap doc + tests: add better examples & test them
  tests: refactor a few tests to use "test_commit --append"
  test-lib functions: add an --append option to test_commit
  test-lib functions: add --author support to test_commit
  test-lib functions: document arguments to test_commit
  test-lib functions: expand "test_commit" comment template
  mailmap: test for silent exiting on missing file/blob
  mailmap tests: get rid of overly complex blame fuzzing
  mailmap tests: add a test for "not a blob" error
  mailmap tests: remove redundant entry in test
  mailmap tests: improve --stdin tests
  mailmap tests: modernize syntax & test idioms
  mailmap tests: use our preferred whitespace syntax
  mailmap doc: start by mentioning the comment syntax
  check-mailmap doc: note config options
  ...

6 files changed, 615 insertions, 291 deletions

diff --git a/t/t1412-reflog-loop.sh b/t/t1412-reflog-loop.sh
index 3acd895..977603f 100755
--- a/t/t1412-reflog-loop.sh
+++ b/t/t1412-reflog-loop.sh
@@ -4,11 +4,8 @@ test_description='reflog walk shows repeated commits again'
 . ./test-lib.sh
 
 test_expect_success 'setup commits' '
-	test_tick &&
-	echo content >file && git add file && git commit -m one &&
-	git tag one &&
-	echo content >>file && git add file && git commit -m two &&
-	git tag two
+	test_commit one file content &&
+	test_commit --append two file content
 '
 
 test_expect_success 'setup reflog with alternating commits' '
diff --git a/t/t2012-checkout-last.sh b/t/t2012-checkout-last.sh
index 028a00d..0e7d47a 100755
--- a/t/t2012-checkout-last.sh
+++ b/t/t2012-checkout-last.sh
@@ -8,13 +8,9 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 . ./test-lib.sh
 
 test_expect_success 'setup' '
-	echo hello >world &&
-	git add world &&
-	git commit -m initial &&
+	test_commit initial world hello &&
 	git branch other &&
-	echo "hello again" >>world &&
-	git add world &&
-	git commit -m second
+	test_commit --append second world "hello again"
 '
 
 test_expect_success '"checkout -" does not work initially' '
@@ -96,9 +92,7 @@ test_expect_success 'switch to twelfth from the last' '
 
 test_expect_success 'merge base test setup' '
 	git checkout -b another other &&
-	echo "hello again" >>world &&
-	git add world &&
-	git commit -m third
+	test_commit --append third world "hello again"
 '
 
 test_expect_success 'another...main' '
diff --git a/t/t4203-mailmap.sh b/t/t4203-mailmap.sh
index 3f82c65..6fb18a3 100755
--- a/t/t4203-mailmap.sh
+++ b/t/t4203-mailmap.sh
@@ -7,28 +7,9 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
 
-fuzz_blame () {
-	sed "
-		s/$_x05[0-9a-f][0-9a-f][0-9a-f]/OBJID/g
-		s/$_x05[0-9a-f][0-9a-f]/OBJI/g
-		s/[-0-9]\{10\} [:0-9]\{8\} [-+][0-9]\{4\}/DATE/g
-	" "$@"
-}
-
-test_expect_success setup '
-	cat >contacts <<- EOF &&
-	$GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL>
-	nick1 <bugs@company.xx>
-	EOF
-
-	echo one >one &&
-	git add one &&
-	test_tick &&
-	git commit -m initial &&
-	echo two >>one &&
-	git add one &&
-	test_tick &&
-	git commit --author "nick1 <bugs@company.xx>" -m second
+test_expect_success 'setup commits and contacts file' '
+	test_commit initial one one &&
+	test_commit --author "nick1 <bugs@company.xx>" --append second one two
 '
 
 test_expect_success 'check-mailmap no arguments' '
@@ -36,7 +17,7 @@ test_expect_success 'check-mailmap no arguments' '
 '
 
 test_expect_success 'check-mailmap arguments' '
-	cat >expect <<- EOF &&
+	cat >expect <<-EOF &&
 	$GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL>
 	nick1 <bugs@company.xx>
 	EOF
@@ -47,150 +28,229 @@ test_expect_success 'check-mailmap arguments' '
 '
 
 test_expect_success 'check-mailmap --stdin' '
-	cat >expect <<- EOF &&
+	cat >expect <<-EOF &&
 	$GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL>
 	nick1 <bugs@company.xx>
 	EOF
-	git check-mailmap --stdin <contacts >actual &&
+	git check-mailmap --stdin <expect >actual &&
 	test_cmp expect actual
 '
 
-test_expect_success 'check-mailmap --stdin arguments' '
+test_expect_success 'check-mailmap --stdin arguments: no mapping' '
+	test_when_finished "rm contacts" &&
+	cat >contacts <<-EOF &&
+	$GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL>
+	nick1 <bugs@company.xx>
+	EOF
 	cat >expect <<-\EOF &&
 	Internal Guy <bugs@company.xy>
 	EOF
-	cat <contacts >>expect &&
+	cat contacts >>expect &&
+
 	git check-mailmap --stdin "Internal Guy <bugs@company.xy>" \
 		<contacts >actual &&
 	test_cmp expect actual
 '
 
+test_expect_success 'check-mailmap --stdin arguments: mapping' '
+	test_when_finished "rm .mailmap" &&
+	cat >.mailmap <<-EOF &&
+	New Name <$GIT_AUTHOR_EMAIL>
+	EOF
+	cat >stdin <<-EOF &&
+	Old Name <$GIT_AUTHOR_EMAIL>
+	EOF
+
+	cp .mailmap expect &&
+	git check-mailmap --stdin <stdin >actual &&
+	test_cmp expect actual &&
+
+	cat .mailmap >>expect &&
+	git check-mailmap --stdin "Another Old Name <$GIT_AUTHOR_EMAIL>" \
+		<stdin >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'check-mailmap bogus contact' '
 	test_must_fail git check-mailmap bogus
 '
 
-cat >expect << EOF
-$GIT_AUTHOR_NAME (1):
-      initial
+test_expect_success 'check-mailmap bogus contact --stdin' '
+	test_must_fail git check-mailmap --stdin bogus </dev/null
+'
 
-nick1 (1):
-      second
+test_expect_success 'No mailmap' '
+	cat >expect <<-EOF &&
+	$GIT_AUTHOR_NAME (1):
+	      initial
 
-EOF
+	nick1 (1):
+	      second
 
-test_expect_success 'No mailmap' '
+	EOF
 	git shortlog HEAD >actual &&
 	test_cmp expect actual
 '
 
-cat >expect <<\EOF
-Repo Guy (1):
-      initial
+test_expect_success 'setup default .mailmap' '
+	cat >default.map <<-EOF
+	Repo Guy <$GIT_AUTHOR_EMAIL>
+	EOF
+'
 
-nick1 (1):
-      second
+test_expect_success 'test default .mailmap' '
+	test_when_finished "rm .mailmap" &&
+	cp default.map .mailmap &&
 
-EOF
+	cat >expect <<-\EOF &&
+	Repo Guy (1):
+	      initial
+
+	nick1 (1):
+	      second
 
-test_expect_success 'default .mailmap' '
-	echo "Repo Guy <$GIT_AUTHOR_EMAIL>" > .mailmap &&
+	EOF
 	git shortlog HEAD >actual &&
 	test_cmp expect actual
 '
 
-# Using a mailmap file in a subdirectory of the repo here, but
-# could just as well have been a file outside of the repository
-cat >expect <<\EOF
-Internal Guy (1):
-      second
+test_expect_success 'mailmap.file set' '
+	test_when_finished "rm .mailmap" &&
+	cp default.map .mailmap &&
 
-Repo Guy (1):
-      initial
+	test_config mailmap.file internal.map &&
+	cat >internal.map <<-\EOF &&
+	Internal Guy <bugs@company.xx>
+	EOF
 
-EOF
-test_expect_success 'mailmap.file set' '
-	mkdir -p internal_mailmap &&
-	echo "Internal Guy <bugs@company.xx>" > internal_mailmap/.mailmap &&
-	git config mailmap.file internal_mailmap/.mailmap &&
+	cat >expect <<-\EOF &&
+	Internal Guy (1):
+	      second
+
+	Repo Guy (1):
+	      initial
+
+	EOF
 	git shortlog HEAD >actual &&
-	test_cmp expect actual
+	test_cmp expect actual &&
+
+	# The internal_mailmap/.mailmap file is an a subdirectory, but
+	# as shown here it can also be outside the repository
+	test_when_finished "rm -rf sub-repo" &&
+	git clone . sub-repo &&
+	(
+		cd sub-repo &&
+		cp ../.mailmap . &&
+		git config mailmap.file ../internal.map &&
+		git shortlog HEAD >actual &&
+		test_cmp ../expect actual
+	)
 '
 
-cat >expect <<\EOF
-External Guy (1):
-      initial
+test_expect_success 'mailmap.file override' '
+	test_config mailmap.file internal.map &&
+	cat >internal.map <<-EOF &&
+	Internal Guy <bugs@company.xx>
+	External Guy <$GIT_AUTHOR_EMAIL>
+	EOF
 
-Internal Guy (1):
-      second
+	cat >expect <<-\EOF &&
+	External Guy (1):
+	      initial
 
-EOF
-test_expect_success 'mailmap.file override' '
-	echo "External Guy <$GIT_AUTHOR_EMAIL>" >> internal_mailmap/.mailmap &&
-	git config mailmap.file internal_mailmap/.mailmap &&
+	Internal Guy (1):
+	      second
+
+	EOF
 	git shortlog HEAD >actual &&
 	test_cmp expect actual
 '
 
-cat >expect <<\EOF
-Repo Guy (1):
-      initial
+test_expect_success 'mailmap.file non-existent' '
+	test_when_finished "rm .mailmap" &&
+	cp default.map .mailmap &&
 
-nick1 (1):
-      second
+	cat >expect <<-\EOF &&
+	Repo Guy (1):
+	      initial
 
-EOF
+	nick1 (1):
+	      second
 
-test_expect_success 'mailmap.file non-existent' '
-	rm internal_mailmap/.mailmap &&
-	rmdir internal_mailmap &&
+	EOF
 	git shortlog HEAD >actual &&
 	test_cmp expect actual
 '
 
-cat >expect <<\EOF
-Internal Guy (1):
-      second
+test_expect_success 'name entry after email entry' '
+	test_when_finished "rm .mailmap" &&
+	cp default.map .mailmap &&
+
+	test_config mailmap.file internal.map &&
+	cat >internal.map <<-\EOF &&
+	<bugs@company.xy> <bugs@company.xx>
+	Internal Guy <bugs@company.xx>
+	EOF
 
-Repo Guy (1):
-      initial
+	cat >expect <<-\EOF &&
+	Internal Guy (1):
+	      second
 
-EOF
+	Repo Guy (1):
+	      initial
+
+	EOF
 
-test_expect_success 'name entry after email entry' '
-	mkdir -p internal_mailmap &&
-	echo "<bugs@company.xy> <bugs@company.xx>" >internal_mailmap/.mailmap &&
-	echo "Internal Guy <bugs@company.xx>" >>internal_mailmap/.mailmap &&
 	git shortlog HEAD >actual &&
 	test_cmp expect actual
 '
 
-cat >expect <<\EOF
-Internal Guy (1):
-      second
+test_expect_success 'name entry after email entry, case-insensitive' '
+	test_when_finished "rm .mailmap" &&
+	cp default.map .mailmap &&
 
-Repo Guy (1):
-      initial
+	test_config mailmap.file internal.map &&
+	cat >internal.map <<-\EOF &&
+	<bugs@company.xy> <bugs@company.xx>
+	Internal Guy <BUGS@Company.xx>
+	EOF
 
-EOF
+	cat >expect <<-\EOF &&
+	Internal Guy (1):
+	      second
 
-test_expect_success 'name entry after email entry, case-insensitive' '
-	mkdir -p internal_mailmap &&
-	echo "<bugs@company.xy> <bugs@company.xx>" >internal_mailmap/.mailmap &&
-	echo "Internal Guy <BUGS@Company.xx>" >>internal_mailmap/.mailmap &&
+	Repo Guy (1):
+	      initial
+
+	EOF
+	git shortlog HEAD >actual &&
+	test_cmp expect actual &&
+
+	cat >internal.map <<-\EOF &&
+	NiCk <BuGs@CoMpAnY.Xy> NICK1 <BUGS@COMPANY.XX>
+	EOF
+
+	cat >expect <<-\EOF &&
+	NiCk (1):
+	      second
+
+	Repo Guy (1):
+	      initial
+
+	EOF
 	git shortlog HEAD >actual &&
 	test_cmp expect actual
 '
 
-cat >expect << EOF
-$GIT_AUTHOR_NAME (1):
-      initial
+test_expect_success 'No mailmap files, but configured' '
+	cat >expect <<-EOF &&
+	$GIT_AUTHOR_NAME (1):
+	      initial
 
-nick1 (1):
-      second
+	nick1 (1):
+	      second
 
-EOF
-test_expect_success 'No mailmap files, but configured' '
-	rm -f .mailmap internal_mailmap/.mailmap &&
+	EOF
 	git shortlog HEAD >actual &&
 	test_cmp expect actual
 '
@@ -198,21 +258,26 @@ test_expect_success 'No mailmap files, but configured' '
 test_expect_success 'setup mailmap blob tests' '
 	git checkout -b map &&
 	test_when_finished "git checkout main" &&
-	cat >just-bugs <<- EOF &&
+	cat >just-bugs <<-\EOF &&
 	Blob Guy <bugs@company.xx>
 	EOF
-	cat >both <<- EOF &&
+	cat >both <<-EOF &&
 	Blob Guy <$GIT_AUTHOR_EMAIL>
 	Blob Guy <bugs@company.xx>
 	EOF
 	printf "Tricky Guy <$GIT_AUTHOR_EMAIL>" >no-newline &&
 	git add just-bugs both no-newline &&
 	git commit -m "my mailmaps" &&
-	echo "Repo Guy <$GIT_AUTHOR_EMAIL>" >.mailmap &&
-	echo "Internal Guy <$GIT_AUTHOR_EMAIL>" >internal.map
+
+	cat >internal.map <<-EOF
+	Internal Guy <$GIT_AUTHOR_EMAIL>
+	EOF
 '
 
 test_expect_success 'mailmap.blob set' '
+	test_when_finished "rm .mailmap" &&
+	cp default.map .mailmap &&
+
 	cat >expect <<-\EOF &&
 	Blob Guy (1):
 	      second
@@ -226,6 +291,9 @@ test_expect_success 'mailmap.blob set' '
 '
 
 test_expect_success 'mailmap.blob overrides .mailmap' '
+	test_when_finished "rm .mailmap" &&
+	cp default.map .mailmap &&
+
 	cat >expect <<-\EOF &&
 	Blob Guy (2):
 	      initial
@@ -252,7 +320,28 @@ test_expect_success 'mailmap.file overrides mailmap.blob' '
 	test_cmp expect actual
 '
 
+test_expect_success 'mailmap.file can be missing' '
+	test_when_finished "rm .mailmap" &&
+	cp default.map .mailmap &&
+
+	test_config mailmap.file nonexistent &&
+	cat >expect <<-\EOF &&
+	Repo Guy (1):
+	      initial
+
+	nick1 (1):
+	      second
+
+	EOF
+	git shortlog HEAD >actual 2>err &&
+	test_must_be_empty err &&
+	test_cmp expect actual
+'
+
 test_expect_success 'mailmap.blob can be missing' '
+	test_when_finished "rm .mailmap" &&
+	cp default.map .mailmap &&
+
 	cat >expect <<-\EOF &&
 	Repo Guy (1):
 	      initial
@@ -261,7 +350,17 @@ test_expect_success 'mailmap.blob can be missing' '
 	      second
 
 	EOF
-	git -c mailmap.blob=map:nonexistent shortlog HEAD >actual &&
+	git -c mailmap.blob=map:nonexistent shortlog HEAD >actual 2>err &&
+	test_must_be_empty err &&
+	test_cmp expect actual
+'
+
+test_expect_success 'mailmap.blob might be the wrong type' '
+	test_when_finished "rm .mailmap" &&
+	cp default.map .mailmap &&
+
+	git -c mailmap.blob=HEAD: shortlog HEAD >actual 2>err &&
+	test_i18ngrep "mailmap is not a blob" err &&
 	test_cmp expect actual
 '
 
@@ -270,11 +369,15 @@ test_expect_success 'mailmap.blob defaults to off in non-bare repo' '
 	(
 		cd non-bare &&
 		test_commit one .mailmap "Fake Name <$GIT_AUTHOR_EMAIL>" &&
-		echo "     1	Fake Name" >expect &&
+		cat >expect <<-\EOF &&
+		     1	Fake Name
+		EOF
 		git shortlog -ns HEAD >actual &&
 		test_cmp expect actual &&
 		rm .mailmap &&
-		echo "     1	$GIT_AUTHOR_NAME" >expect &&
+		cat >expect <<-EOF &&
+		     1	$GIT_AUTHOR_NAME
+		EOF
 		git shortlog -ns HEAD >actual &&
 		test_cmp expect actual
 	)
@@ -284,7 +387,9 @@ test_expect_success 'mailmap.blob defaults to HEAD:.mailmap in bare repo' '
 	git clone --bare non-bare bare &&
 	(
 		cd bare &&
-		echo "     1	Fake Name" >expect &&
+		cat >expect <<-\EOF &&
+		     1	Fake Name
+		EOF
 		git shortlog -ns HEAD >actual &&
 		test_cmp expect actual
 	)
@@ -303,178 +408,258 @@ test_expect_success 'mailmap.blob can handle blobs without trailing newline' '
 	test_cmp expect actual
 '
 
-test_expect_success 'cleanup after mailmap.blob tests' '
-	rm -f .mailmap
-'
-
 test_expect_success 'single-character name' '
-	echo "     1	A <$GIT_AUTHOR_EMAIL>" >expect &&
-	echo "     1	nick1 <bugs@company.xx>" >>expect &&
-	echo "A <$GIT_AUTHOR_EMAIL>" >.mailmap &&
 	test_when_finished "rm .mailmap" &&
+	cat >.mailmap <<-EOF &&
+	A <$GIT_AUTHOR_EMAIL>
+	EOF
+
+	cat >expect <<-EOF &&
+	     1	A <$GIT_AUTHOR_EMAIL>
+	     1	nick1 <bugs@company.xx>
+	EOF
 	git shortlog -es HEAD >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success 'preserve canonical email case' '
-	echo "     1	$GIT_AUTHOR_NAME <AUTHOR@example.com>" >expect &&
-	echo "     1	nick1 <bugs@company.xx>" >>expect &&
-	echo "<AUTHOR@example.com> <$GIT_AUTHOR_EMAIL>" >.mailmap &&
 	test_when_finished "rm .mailmap" &&
+	cat >.mailmap <<-EOF &&
+	<AUTHOR@example.com> <$GIT_AUTHOR_EMAIL>
+	EOF
+
+	cat >expect <<-EOF &&
+	     1	$GIT_AUTHOR_NAME <AUTHOR@example.com>
+	     1	nick1 <bugs@company.xx>
+	EOF
 	git shortlog -es HEAD >actual &&
 	test_cmp expect actual
 '
 
-# Extended mailmap configurations should give us the following output for shortlog
-cat >expect << EOF
-$GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL> (1):
-      initial
+test_expect_success 'gitmailmap(5) example output: setup' '
+	test_create_repo doc &&
+	test_commit -C doc --author "Joe Developer <joe@example.com>" A &&
+	test_commit -C doc --author "Joe R. Developer <joe@example.com>" B &&
+	test_commit -C doc --author "Jane Doe <jane@example.com>" C &&
+	test_commit -C doc --author "Jane Doe <jane@laptop.(none)>" D &&
+	test_commit -C doc --author "Jane D. <jane@desktop.(none)>" E
+'
+
+test_expect_success 'gitmailmap(5) example output: example #1' '
+	test_config -C doc mailmap.file ../doc.map &&
+	cat >doc.map <<-\EOF &&
+	Joe R. Developer <joe@example.com>
+	Jane Doe <jane@example.com>
+	Jane Doe <jane@desktop.(none)>
+	EOF
+
+	cat >expect <<-\EOF &&
+	Author Joe Developer <joe@example.com> maps to Joe R. Developer <joe@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author Joe R. Developer <joe@example.com> maps to Joe R. Developer <joe@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author Jane Doe <jane@example.com> maps to Jane Doe <jane@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author Jane Doe <jane@laptop.(none)> maps to Jane Doe <jane@laptop.(none)>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author Jane D <jane@desktop.(none)> maps to Jane Doe <jane@desktop.(none)>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+	EOF
+	git -C doc log --reverse --pretty=format:"Author %an <%ae> maps to %aN <%aE>%nCommitter %cn <%ce> maps to %cN <%cE>%n" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'gitmailmap(5) example output: example #2' '
+	test_config -C doc mailmap.file ../doc.map &&
+	cat >doc.map <<-\EOF &&
+	Joe R. Developer <joe@example.com>
+	Jane Doe <jane@example.com> <jane@laptop.(none)>
+	Jane Doe <jane@example.com> <jane@desktop.(none)>
+	EOF
+
+	cat >expect <<-\EOF &&
+	Author Joe Developer <joe@example.com> maps to Joe R. Developer <joe@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author Joe R. Developer <joe@example.com> maps to Joe R. Developer <joe@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author Jane Doe <jane@example.com> maps to Jane Doe <jane@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author Jane Doe <jane@laptop.(none)> maps to Jane Doe <jane@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author Jane D <jane@desktop.(none)> maps to Jane Doe <jane@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+	EOF
+	git -C doc log --reverse --pretty=format:"Author %an <%ae> maps to %aN <%aE>%nCommitter %cn <%ce> maps to %cN <%cE>%n" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'gitmailmap(5) example output: example #3' '
+	test_config -C doc mailmap.file ../doc.map &&
+	cat >>doc.map <<-\EOF &&
+	Joe R. Developer <joe@example.com> Joe <bugs@example.com>
+	Jane Doe <jane@example.com> Jane <bugs@example.com>
+	EOF
 
-CTO <cto@company.xx> (1):
-      seventh
+	test_commit -C doc --author "Joe <bugs@example.com>" F &&
+	test_commit -C doc --author "Jane <bugs@example.com>" G &&
 
-Other Author <other@author.xx> (2):
-      third
-      fourth
+	cat >>expect <<-\EOF &&
 
-Santa Claus <santa.claus@northpole.xx> (2):
-      fifth
-      sixth
+	Author Joe <bugs@example.com> maps to Joe R. Developer <joe@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
 
-Some Dude <some@dude.xx> (1):
-      second
+	Author Jane <bugs@example.com> maps to Jane Doe <jane@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+	EOF
+	git -C doc log --reverse --pretty=format:"Author %an <%ae> maps to %aN <%aE>%nCommitter %cn <%ce> maps to %cN <%cE>%n" >actual &&
+	test_cmp expect actual
+'
 
-EOF
 
 test_expect_success 'Shortlog output (complex mapping)' '
-	echo three >>one &&
-	git add one &&
-	test_tick &&
-	git commit --author "nick2 <bugs@company.xx>" -m third &&
-
-	echo four >>one &&
-	git add one &&
-	test_tick &&
-	git commit --author "nick2 <nick2@company.xx>" -m fourth &&
-
-	echo five >>one &&
-	git add one &&
-	test_tick &&
-	git commit --author "santa <me@company.xx>" -m fifth &&
-
-	echo six >>one &&
-	git add one &&
-	test_tick &&
-	git commit --author "claus <me@company.xx>" -m sixth &&
-
-	echo seven >>one &&
-	git add one &&
-	test_tick &&
-	git commit --author "CTO <cto@coompany.xx>" -m seventh &&
-
-	mkdir -p internal_mailmap &&
-	echo "Committed <$GIT_COMMITTER_EMAIL>" > internal_mailmap/.mailmap &&
-	echo "<cto@company.xx>                       <cto@coompany.xx>" >> internal_mailmap/.mailmap &&
-	echo "Some Dude <some@dude.xx>         nick1 <bugs@company.xx>" >> internal_mailmap/.mailmap &&
-	echo "Other Author <other@author.xx>   nick2 <bugs@company.xx>" >> internal_mailmap/.mailmap &&
-	echo "Other Author <other@author.xx>         <nick2@company.xx>" >> internal_mailmap/.mailmap &&
-	echo "Santa Claus <santa.claus@northpole.xx> <me@company.xx>" >> internal_mailmap/.mailmap &&
-	echo "Santa Claus <santa.claus@northpole.xx> <me@company.xx>" >> internal_mailmap/.mailmap &&
+	test_config mailmap.file complex.map &&
+	cat >complex.map <<-EOF &&
+	Committed <$GIT_COMMITTER_EMAIL>
+	<cto@company.xx> <cto@coompany.xx>
+	Some Dude <some@dude.xx>         nick1 <bugs@company.xx>
+	Other Author <other@author.xx>   nick2 <bugs@company.xx>
+	Other Author <other@author.xx>         <nick2@company.xx>
+	Santa Claus <santa.claus@northpole.xx> <me@company.xx>
+	EOF
+
+	test_commit --author "nick2 <bugs@company.xx>" --append third one three &&
+	test_commit --author "nick2 <nick2@company.xx>" --append fourth one four &&
+	test_commit --author "santa <me@company.xx>" --append fifth one five &&
+	test_commit --author "claus <me@company.xx>" --append sixth one six &&
+	test_commit --author "CTO <cto@coompany.xx>" --append seventh one seven &&
+
+	cat >expect <<-EOF &&
+	$GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL> (1):
+	      initial
+
+	CTO <cto@company.xx> (1):
+	      seventh
+
+	Other Author <other@author.xx> (2):
+	      third
+	      fourth
+
+	Santa Claus <santa.claus@northpole.xx> (2):
+	      fifth
+	      sixth
+
+	Some Dude <some@dude.xx> (1):
+	      second
+
+	EOF
 
 	git shortlog -e HEAD >actual &&
 	test_cmp expect actual
 
 '
 
-# git log with --pretty format which uses the name and email mailmap placemarkers
-cat >expect << EOF
-Author CTO <cto@coompany.xx> maps to CTO <cto@company.xx>
-Committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> maps to Committed <$GIT_COMMITTER_EMAIL>
+test_expect_success 'Log output (complex mapping)' '
+	test_config mailmap.file complex.map &&
 
-Author claus <me@company.xx> maps to Santa Claus <santa.claus@northpole.xx>
-Committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> maps to Committed <$GIT_COMMITTER_EMAIL>
+	cat >expect <<-EOF &&
+	Author CTO <cto@coompany.xx> maps to CTO <cto@company.xx>
+	Committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> maps to Committed <$GIT_COMMITTER_EMAIL>
 
-Author santa <me@company.xx> maps to Santa Claus <santa.claus@northpole.xx>
-Committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> maps to Committed <$GIT_COMMITTER_EMAIL>
+	Author claus <me@company.xx> maps to Santa Claus <santa.claus@northpole.xx>
+	Committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> maps to Committed <$GIT_COMMITTER_EMAIL>
 
-Author nick2 <nick2@company.xx> maps to Other Author <other@author.xx>
-Committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> maps to Committed <$GIT_COMMITTER_EMAIL>
+	Author santa <me@company.xx> maps to Santa Claus <santa.claus@northpole.xx>
+	Committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> maps to Committed <$GIT_COMMITTER_EMAIL>
 
-Author nick2 <bugs@company.xx> maps to Other Author <other@author.xx>
-Committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> maps to Committed <$GIT_COMMITTER_EMAIL>
+	Author nick2 <nick2@company.xx> maps to Other Author <other@author.xx>
+	Committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> maps to Committed <$GIT_COMMITTER_EMAIL>
 
-Author nick1 <bugs@company.xx> maps to Some Dude <some@dude.xx>
-Committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> maps to Committed <$GIT_COMMITTER_EMAIL>
+	Author nick2 <bugs@company.xx> maps to Other Author <other@author.xx>
+	Committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> maps to Committed <$GIT_COMMITTER_EMAIL>
 
-Author $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL> maps to $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL>
-Committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> maps to Committed <$GIT_COMMITTER_EMAIL>
-EOF
+	Author nick1 <bugs@company.xx> maps to Some Dude <some@dude.xx>
+	Committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> maps to Committed <$GIT_COMMITTER_EMAIL>
+
+	Author $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL> maps to $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL>
+	Committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> maps to Committed <$GIT_COMMITTER_EMAIL>
+	EOF
 
-test_expect_success 'Log output (complex mapping)' '
 	git log --pretty=format:"Author %an <%ae> maps to %aN <%aE>%nCommitter %cn <%ce> maps to %cN <%cE>%n" >actual &&
 	test_cmp expect actual
 '
 
-cat >expect << EOF
-Author email cto@coompany.xx has local-part cto
-Committer email $GIT_COMMITTER_EMAIL has local-part $TEST_COMMITTER_LOCALNAME
+test_expect_success 'Log output (local-part email address)' '
+	cat >expect <<-EOF &&
+	Author email cto@coompany.xx has local-part cto
+	Committer email $GIT_COMMITTER_EMAIL has local-part $TEST_COMMITTER_LOCALNAME
 
-Author email me@company.xx has local-part me
-Committer email $GIT_COMMITTER_EMAIL has local-part $TEST_COMMITTER_LOCALNAME
+	Author email me@company.xx has local-part me
+	Committer email $GIT_COMMITTER_EMAIL has local-part $TEST_COMMITTER_LOCALNAME
 
-Author email me@company.xx has local-part me
-Committer email $GIT_COMMITTER_EMAIL has local-part $TEST_COMMITTER_LOCALNAME
+	Author email me@company.xx has local-part me
+	Committer email $GIT_COMMITTER_EMAIL has local-part $TEST_COMMITTER_LOCALNAME
 
-Author email nick2@company.xx has local-part nick2
-Committer email $GIT_COMMITTER_EMAIL has local-part $TEST_COMMITTER_LOCALNAME
+	Author email nick2@company.xx has local-part nick2
+	Committer email $GIT_COMMITTER_EMAIL has local-part $TEST_COMMITTER_LOCALNAME
 
-Author email bugs@company.xx has local-part bugs
-Committer email $GIT_COMMITTER_EMAIL has local-part $TEST_COMMITTER_LOCALNAME
+	Author email bugs@company.xx has local-part bugs
+	Committer email $GIT_COMMITTER_EMAIL has local-part $TEST_COMMITTER_LOCALNAME
 
-Author email bugs@company.xx has local-part bugs
-Committer email $GIT_COMMITTER_EMAIL has local-part $TEST_COMMITTER_LOCALNAME
+	Author email bugs@company.xx has local-part bugs
+	Committer email $GIT_COMMITTER_EMAIL has local-part $TEST_COMMITTER_LOCALNAME
 
-Author email author@example.com has local-part author
-Committer email $GIT_COMMITTER_EMAIL has local-part $TEST_COMMITTER_LOCALNAME
-EOF
+	Author email author@example.com has local-part author
+	Committer email $GIT_COMMITTER_EMAIL has local-part $TEST_COMMITTER_LOCALNAME
+	EOF
 
-test_expect_success 'Log output (local-part email address)' '
 	git log --pretty=format:"Author email %ae has local-part %al%nCommitter email %ce has local-part %cl%n" >actual &&
 	test_cmp expect actual
 '
 
-cat >expect << EOF
-Author: CTO <cto@company.xx>
-Author: Santa Claus <santa.claus@northpole.xx>
-Author: Santa Claus <santa.claus@northpole.xx>
-Author: Other Author <other@author.xx>
-Author: Other Author <other@author.xx>
-Author: Some Dude <some@dude.xx>
-Author: $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL>
-EOF
-
 test_expect_success 'Log output with --use-mailmap' '
+	test_config mailmap.file complex.map &&
+
+	cat >expect <<-EOF &&
+	Author: CTO <cto@company.xx>
+	Author: Santa Claus <santa.claus@northpole.xx>
+	Author: Santa Claus <santa.claus@northpole.xx>
+	Author: Other Author <other@author.xx>
+	Author: Other Author <other@author.xx>
+	Author: Some Dude <some@dude.xx>
+	Author: $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL>
+	EOF
+
 	git log --use-mailmap | grep Author >actual &&
 	test_cmp expect actual
 '
 
-cat >expect << EOF
-Author: CTO <cto@company.xx>
-Author: Santa Claus <santa.claus@northpole.xx>
-Author: Santa Claus <santa.claus@northpole.xx>
-Author: Other Author <other@author.xx>
-Author: Other Author <other@author.xx>
-Author: Some Dude <some@dude.xx>
-Author: $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL>
-EOF
-
 test_expect_success 'Log output with log.mailmap' '
+	test_config mailmap.file complex.map &&
+
+	cat >expect <<-EOF &&
+	Author: CTO <cto@company.xx>
+	Author: Santa Claus <santa.claus@northpole.xx>
+	Author: Santa Claus <santa.claus@northpole.xx>
+	Author: Other Author <other@author.xx>
+	Author: Other Author <other@author.xx>
+	Author: Some Dude <some@dude.xx>
+	Author: $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL>
+	EOF
+
 	git -c log.mailmap=True log | grep Author >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success 'log.mailmap=false disables mailmap' '
-	cat >expect <<- EOF &&
+	cat >expect <<-EOF &&
 	Author: CTO <cto@coompany.xx>
 	Author: claus <me@company.xx>
 	Author: santa <me@company.xx>
@@ -483,12 +668,12 @@ test_expect_success 'log.mailmap=false disables mailmap' '
 	Author: nick1 <bugs@company.xx>
 	Author: $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL>
 	EOF
-	git -c log.mailmap=False log | grep Author > actual &&
+	git -c log.mailmap=false log | grep Author >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success '--no-use-mailmap disables mailmap' '
-	cat >expect <<- EOF &&
+	cat >expect <<-EOF &&
 	Author: CTO <cto@coompany.xx>
 	Author: claus <me@company.xx>
 	Author: santa <me@company.xx>
@@ -501,60 +686,200 @@ test_expect_success '--no-use-mailmap disables mailmap' '
 	test_cmp expect actual
 '
 
-cat >expect <<\EOF
-Author: Santa Claus <santa.claus@northpole.xx>
-Author: Santa Claus <santa.claus@northpole.xx>
-EOF
-
 test_expect_success 'Grep author with --use-mailmap' '
+	test_config mailmap.file complex.map &&
+
+	cat >expect <<-\EOF &&
+	Author: Santa Claus <santa.claus@northpole.xx>
+	Author: Santa Claus <santa.claus@northpole.xx>
+	EOF
 	git log --use-mailmap --author Santa | grep Author >actual &&
 	test_cmp expect actual
 '
-cat >expect <<\EOF
-Author: Santa Claus <santa.claus@northpole.xx>
-Author: Santa Claus <santa.claus@northpole.xx>
-EOF
 
 test_expect_success 'Grep author with log.mailmap' '
+	test_config mailmap.file complex.map &&
+
+	cat >expect <<-\EOF &&
+	Author: Santa Claus <santa.claus@northpole.xx>
+	Author: Santa Claus <santa.claus@northpole.xx>
+	EOF
+
 	git -c log.mailmap=True log --author Santa | grep Author >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success 'log.mailmap is true by default these days' '
+	test_config mailmap.file complex.map &&
 	git log --author Santa | grep Author >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success 'Only grep replaced author with --use-mailmap' '
+	test_config mailmap.file complex.map &&
 	git log --use-mailmap --author "<cto@coompany.xx>" >actual &&
 	test_must_be_empty actual
 '
 
-# git blame
-cat >expect <<EOF
-^OBJI ($GIT_AUTHOR_NAME     DATE 1) one
-OBJID (Some Dude    DATE 2) two
-OBJID (Other Author DATE 3) three
-OBJID (Other Author DATE 4) four
-OBJID (Santa Claus  DATE 5) five
-OBJID (Santa Claus  DATE 6) six
-OBJID (CTO          DATE 7) seven
-EOF
-test_expect_success 'Blame output (complex mapping)' '
-	git blame one >actual &&
-	fuzz_blame actual >actual.fuzz &&
+test_expect_success 'Blame --porcelain output (complex mapping)' '
+	test_config mailmap.file complex.map &&
+
+	cat >expect <<-EOF &&
+	1 1 1
+	A U Thor
+	2 2 1
+	Some Dude
+	3 3 1
+	Other Author
+	4 4 1
+	Other Author
+	5 5 1
+	Santa Claus
+	6 6 1
+	Santa Claus
+	7 7 1
+	CTO
+	EOF
+
+	git blame --porcelain one >actual.blame &&
+	grep -E \
+		-e "[0-9]+ [0-9]+ [0-9]+$" \
+		-e "^author .*$" \
+		actual.blame >actual.grep &&
+	cut -d " " -f2-4 <actual.grep >actual.fuzz &&
 	test_cmp expect actual.fuzz
 '
 
-cat >expect <<\EOF
-Some Dude <some@dude.xx>
-EOF
+test_expect_success 'Blame output (complex mapping)' '
+	git -c mailmap.file=complex.map blame one >a &&
+	git blame one >b &&
+	test_file_not_empty a &&
+	! cmp a b
+'
 
 test_expect_success 'commit --author honors mailmap' '
+	test_config mailmap.file complex.map &&
+
+	cat >expect <<-\EOF &&
+	Some Dude <some@dude.xx>
+	EOF
+
 	test_must_fail git commit --author "nick" --allow-empty -meight &&
 	git commit --author "Some Dude" --allow-empty -meight &&
 	git show --pretty=format:"%an <%ae>%n" >actual &&
 	test_cmp expect actual
 '
 
+test_expect_success 'comment syntax: setup' '
+	test_create_repo comm &&
+	test_commit -C comm --author "A <a@example.com>" A &&
+	test_commit -C comm --author "B <b@example.com>" B &&
+	test_commit -C comm --author "C <#@example.com>" C &&
+	test_commit -C comm --author "D <d@e#ample.com>" D &&
+
+	test_config -C comm mailmap.file ../doc.map &&
+	cat >>doc.map <<-\EOF &&
+	# Ah <a@example.com>
+
+	; Bee <b@example.com>
+	Cee <cee@example.com> <#@example.com>
+	Dee <dee@example.com> <d@e#ample.com>
+	EOF
+
+	cat >expect <<-\EOF &&
+	Author A <a@example.com> maps to A <a@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author B <b@example.com> maps to ; Bee <b@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author C <#@example.com> maps to Cee <cee@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author D <d@e#ample.com> maps to Dee <dee@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+	EOF
+	git -C comm log --reverse --pretty=format:"Author %an <%ae> maps to %aN <%aE>%nCommitter %cn <%ce> maps to %cN <%cE>%n" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'whitespace syntax: setup' '
+	test_create_repo space &&
+	test_commit -C space --author "A <a@example.com>" A &&
+	test_commit -C space --author "B <b@example.com>" B &&
+	test_commit -C space --author " C <c@example.com>" C &&
+	test_commit -C space --author " D  <d@example.com>" D &&
+	test_commit -C space --author "E E <e@example.com>" E &&
+	test_commit -C space --author "F  F <f@example.com>" F &&
+	test_commit -C space --author "G   G <g@example.com>" G &&
+	test_commit -C space --author "H   H <h@example.com>" H &&
+
+	test_config -C space mailmap.file ../space.map &&
+	cat >>space.map <<-\EOF &&
+	Ah <ah@example.com> < a@example.com >
+	Bee <bee@example.com  > <  b@example.com  >
+	Cee <cee@example.com> C <c@example.com>
+	dee <dee@example.com>  D  <d@example.com>
+	eee <eee@example.com> E E <e@example.com>
+	eff <eff@example.com> F  F <f@example.com>
+	gee <gee@example.com> G   G <g@example.com>
+	aitch <aitch@example.com> H  H <h@example.com>
+	EOF
+
+	cat >expect <<-\EOF &&
+	Author A <a@example.com> maps to A <a@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author B <b@example.com> maps to B <b@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author C <c@example.com> maps to Cee <cee@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author D <d@example.com> maps to dee <dee@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author E E <e@example.com> maps to eee <eee@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author F  F <f@example.com> maps to eff <eff@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author G   G <g@example.com> maps to gee <gee@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author H   H <h@example.com> maps to H   H <h@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+	EOF
+	git -C space log --reverse --pretty=format:"Author %an <%ae> maps to %aN <%aE>%nCommitter %cn <%ce> maps to %cN <%cE>%n" >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'empty syntax: setup' '
+	test_create_repo empty &&
+	test_commit -C empty --author "A <>" A &&
+	test_commit -C empty --author "B <b@example.com>" B &&
+	test_commit -C empty --author "C <c@example.com>" C &&
+
+	test_config -C empty mailmap.file ../empty.map &&
+	cat >>empty.map <<-\EOF &&
+	Ah <ah@example.com> <>
+	Bee <bee@example.com> <>
+	Cee <> <c@example.com>
+	EOF
+
+	cat >expect <<-\EOF &&
+	Author A <> maps to Bee <bee@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author B <b@example.com> maps to B <b@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+
+	Author C <c@example.com> maps to C <c@example.com>
+	Committer C O Mitter <committer@example.com> maps to C O Mitter <committer@example.com>
+	EOF
+	git -C empty log --reverse --pretty=format:"Author %an <%ae> maps to %aN <%aE>%nCommitter %cn <%ce> maps to %cN <%cE>%n" >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t7509-commit-authorship.sh b/t/t7509-commit-authorship.sh
index 500ab2f..ee6c474 100755
--- a/t/t7509-commit-authorship.sh
+++ b/t/t7509-commit-authorship.sh
@@ -18,11 +18,8 @@ message_body () {
 }
 
 test_expect_success '-C option copies authorship and message' '
-	echo "Initial" >foo &&
-	git add foo &&
-	test_tick &&
-	git commit -m "Initial Commit" --author Frigate\ \<flying@over.world\> &&
-	git tag Initial &&
+	test_commit --author Frigate\ \<flying@over.world\> \
+		"Initial Commit" foo Initial Initial &&
 	echo "Test 1" >>foo &&
 	test_tick &&
 	git commit -a -C Initial &&
diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index 9f1aa9e..8f7591c 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh
@@ -690,21 +690,9 @@ test_expect_success 'grep -C1 hunk mark between files' '
 '
 
 test_expect_success 'log grep setup' '
-	echo a >>file &&
-	test_tick &&
-	GIT_AUTHOR_NAME="With * Asterisk" \
-	GIT_AUTHOR_EMAIL="xyzzy@frotz.com" \
-	git commit -a -m "second" &&
-
-	echo a >>file &&
-	test_tick &&
-	git commit -a -m "third" &&
-
-	echo a >>file &&
-	test_tick &&
-	GIT_AUTHOR_NAME="Night Fall" \
-	GIT_AUTHOR_EMAIL="nitfol@frobozz.com" \
-	git commit -a -m "fourth"
+	test_commit --append --author "With * Asterisk <xyzzy@frotz.com>" second file a &&
+	test_commit --append third file a &&
+	test_commit --append --author "Night Fall <nitfol@frobozz.com>" fourth file a
 '
 
 test_expect_success 'log grep (1)' '
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 2f08ce7..c31a411 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -178,19 +178,28 @@ debug () {
 	GIT_DEBUGGER="${GIT_DEBUGGER}" "$@" <&6 >&5 2>&7
 }
 
-# Call test_commit with the arguments
-# [-C <directory>] <message> [<file> [<contents> [<tag>]]]"
+# Usage: test_commit [options] <message> [<file> [<contents> [<tag>]]]
+#   -C <dir>:
+#	Run all git commands in directory <dir>
+#   --notick
+#	Do not call test_tick before making a commit
+#   --append
+#	Use "echo >>" instead of "echo >" when writing "<contents>" to
+#	"<file>"
+#   --signoff
+#	Invoke "git commit" with --signoff
+#   --author=<author>
+#	Invoke "git commit" with --author=<author>
 #
 # This will commit a file with the given contents and the given commit
 # message, and tag the resulting commit with the given tag name.
 #
 # <file>, <contents>, and <tag> all default to <message>.
-#
-# If the first argument is "-C", the second argument is used as a path for
-# the git invocations.
 
 test_commit () {
 	notick= &&
+	append= &&
+	author= &&
 	signoff= &&
 	indir= &&
 	while test $# != 0
@@ -199,6 +208,13 @@ test_commit () {
 		--notick)
 			notick=yes
 			;;
+		--append)
+			append=yes
+			;;
+		--author)
+			author="$2"
+			shift
+			;;
 		--signoff)
 			signoff="$1"
 			;;
@@ -214,13 +230,20 @@ test_commit () {
 	done &&
 	indir=${indir:+"$indir"/} &&
 	file=${2:-"$1.t"} &&
-	echo "${3-$1}" > "$indir$file" &&
+	if test -n "$append"
+	then
+		echo "${3-$1}" >>"$indir$file"
+	else
+		echo "${3-$1}" >"$indir$file"
+	fi &&
 	git ${indir:+ -C "$indir"} add "$file" &&
 	if test -z "$notick"
 	then
 		test_tick
 	fi &&
-	git ${indir:+ -C "$indir"} commit $signoff -m "$1" &&
+	git ${indir:+ -C "$indir"} commit \
+	    ${author:+ --author "$author"} \
+	    $signoff -m "$1" &&
 	git ${indir:+ -C "$indir"} tag "${4:-$1}"
 }