Merge branch 'jt/trailer-with-cruft'

Update "interpret-trailers" machinery and teaches it that people in
real world write all sorts of crufts in the "trailer" that was
originally designed to have the neat-o "Mail-Header: like thing"
and nothing else.

* jt/trailer-with-cruft:
  trailer: support values folded to multiple lines
  trailer: forbid leading whitespace in trailers
  trailer: allow non-trailers in trailer block
  trailer: clarify failure modes in parse_trailer
  trailer: make args have their own struct
  trailer: streamline trailer item create and add
  trailer: use list.h for doubly-linked list
  trailer: improve const correctness

1 files changed, 299 insertions, 0 deletions

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 &&