Merge branch 'jk/trailers-parse'

"git interpret-trailers" has been taught a "--parse" and a few
other options to make it easier for scripts to grab existing
trailer lines from a commit log message.

* jk/trailers-parse:
  doc/interpret-trailers: fix "the this" typo
  pretty: support normalization options for %(trailers)
  t4205: refactor %(trailers) tests
  pretty: move trailer formatting to trailer.c
  interpret-trailers: add --parse convenience option
  interpret-trailers: add an option to unfold values
  interpret-trailers: add an option to show only existing trailers
  interpret-trailers: add an option to show only the trailers
  trailer: put process_trailers() options into a struct

2 files changed, 120 insertions, 7 deletions

diff --git a/t/t4205-log-pretty-formats.sh b/t/t4205-log-pretty-formats.sh
index 18aa1b5889..ec5f530102 100755
--- a/t/t4205-log-pretty-formats.sh
+++ b/t/t4205-log-pretty-formats.sh
@@ -539,25 +539,62 @@ cat >trailers <<EOF
 Signed-off-by: A U Thor <author@example.com>
 Acked-by: A U Thor <author@example.com>
 [ v2 updated patch description ]
-Signed-off-by: A U Thor <author@example.com>
+Signed-off-by: A U Thor
+  <author@example.com>
 EOF
 
-test_expect_success 'pretty format %(trailers) shows trailers' '
+unfold () {
+	perl -0pe 's/\n\s+/ /'
+}
+
+test_expect_success 'set up trailer tests' '
 	echo "Some contents" >trailerfile &&
 	git add trailerfile &&
-	git commit -F - <<-EOF &&
+	git commit -F - <<-EOF
 	trailers: this commit message has trailers
 
 	This commit is a test commit with trailers at the end. We parse this
-	message and display the trailers using %bT
+	message and display the trailers using %(trailers).
 
 	$(cat trailers)
 	EOF
+'
+
+test_expect_success 'pretty format %(trailers) shows trailers' '
 	git log --no-walk --pretty="%(trailers)" >actual &&
-	cat >expect <<-EOF &&
-	$(cat trailers)
+	{
+		cat trailers &&
+		echo
+	} >expect &&
+	test_cmp expect actual
+'
 
-	EOF
+test_expect_success '%(trailers:only) shows only "key: value" trailers' '
+	git log --no-walk --pretty="%(trailers:only)" >actual &&
+	{
+		grep -v patch.description <trailers &&
+		echo
+	} >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success '%(trailers:unfold) unfolds trailers' '
+	git log --no-walk --pretty="%(trailers:unfold)" >actual &&
+	{
+		unfold <trailers &&
+		echo
+	} >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success ':only and :unfold work together' '
+	git log --no-walk --pretty="%(trailers:only:unfold)" >actual &&
+	git log --no-walk --pretty="%(trailers:unfold:only)" >reverse &&
+	test_cmp actual reverse &&
+	{
+		grep -v patch.description <trailers | unfold &&
+		echo
+	} >expect &&
 	test_cmp expect actual
 '
 
diff --git a/t/t7513-interpret-trailers.sh b/t/t7513-interpret-trailers.sh
index adbdf54f8d..164719d1c9 100755
--- a/t/t7513-interpret-trailers.sh
+++ b/t/t7513-interpret-trailers.sh
@@ -1341,4 +1341,80 @@ test_expect_success 'with cut line' '
 	test_cmp expected actual
 '
 
+test_expect_success 'only trailers' '
+	git config trailer.sign.command "echo config-value" &&
+	cat >expected <<-\EOF &&
+		existing: existing-value
+		sign: config-value
+		added: added-value
+	EOF
+	git interpret-trailers \
+		--trailer added:added-value \
+		--only-trailers >actual <<-\EOF &&
+		my subject
+
+		my body
+
+		existing: existing-value
+	EOF
+	test_cmp expected actual
+'
+
+test_expect_success 'only-trailers omits non-trailer in middle of block' '
+	git config trailer.sign.command "echo config-value" &&
+	cat >expected <<-\EOF &&
+		Signed-off-by: nobody <nobody@nowhere>
+		Signed-off-by: somebody <somebody@somewhere>
+		sign: config-value
+	EOF
+	git interpret-trailers --only-trailers >actual <<-\EOF &&
+		subject
+
+		it is important that the trailers below are signed-off-by
+		so that they meet the "25% trailers Git knows about" heuristic
+
+		Signed-off-by: nobody <nobody@nowhere>
+		this is not a trailer
+		Signed-off-by: somebody <somebody@somewhere>
+	EOF
+	test_cmp expected actual
+'
+
+test_expect_success 'only input' '
+	git config trailer.sign.command "echo config-value" &&
+	cat >expected <<-\EOF &&
+		existing: existing-value
+	EOF
+	git interpret-trailers \
+		--only-trailers --only-input >actual <<-\EOF &&
+		my subject
+
+		my body
+
+		existing: existing-value
+	EOF
+	test_cmp expected actual
+'
+
+test_expect_success 'unfold' '
+	cat >expected <<-\EOF &&
+		foo: continued across several lines
+	EOF
+	# pass through tr to make leading and trailing whitespace more obvious
+	tr _ " " <<-\EOF |
+		my subject
+
+		my body
+
+		foo:_
+		__continued
+		___across
+		____several
+		_____lines
+		___
+	EOF
+	git interpret-trailers --only-trailers --only-input --unfold >actual &&
+	test_cmp expected actual
+'
+
 test_done