t/t3511: add some tests of 'cherry-pick -s' functionality

Add some tests to ensure that 'cherry-pick -s' operates in the following
manner:

   * Inserts a blank line before appending a s-o-b to a commit message that
     does not contain a s-o-b footer

   * Does not mistake first line "subject: description" as a s-o-b footer

   * Does not mistake single word message body as conforming to rfc2822

   * Appends a s-o-b when last s-o-b in footer does not match committer
     s-o-b, even when committer's s-o-b exists elsewhere in footer.

   * Does not append a s-o-b when last s-o-b matches committer s-o-b

   * Correctly detects a non-conforming footer containing a mix of s-o-b
     like elements and s-o-b elements. (marked "expect failure")

Signed-off-by: Brandon Casey <bcasey@nvidia.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t3511-cherry-pick-x.sh

@@ -0,0 +1,111 @@
+#!/bin/sh
+
+test_description='Test cherry-pick -x and -s'
+
+. ./test-lib.sh
+
+pristine_detach () {
+	git cherry-pick --quit &&
+	git checkout -f "$1^0" &&
+	git read-tree -u --reset HEAD &&
+	git clean -d -f -f -q -x
+}
+
+mesg_one_line='base: commit message'
+
+mesg_no_footer="$mesg_one_line
+
+OneWordBodyThatsNotA-S-o-B"
+
+mesg_with_footer="$mesg_no_footer
+
+Signed-off-by: $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>
+Signed-off-by: A.U. Thor <author@example.com>
+Signed-off-by: B.U. Thor <buthor@example.com>"
+
+mesg_broken_footer="$mesg_no_footer
+
+The signed-off-by string should begin with the words Signed-off-by followed
+by a colon and space, and then the signers name and email address. e.g.
+Signed-off-by: $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>"
+
+mesg_with_footer_sob="$mesg_with_footer
+Signed-off-by: $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>"
+
+
+test_expect_success setup '
+	git config advice.detachedhead false &&
+	echo unrelated >unrelated &&
+	git add unrelated &&
+	test_commit initial foo a &&
+	test_commit "$mesg_one_line" foo b mesg-one-line &&
+	git reset --hard initial &&
+	test_commit "$mesg_no_footer" foo b mesg-no-footer &&
+	git reset --hard initial &&
+	test_commit "$mesg_broken_footer" foo b mesg-broken-footer &&
+	git reset --hard initial &&
+	test_commit "$mesg_with_footer" foo b mesg-with-footer &&
+	git reset --hard initial &&
+	test_commit "$mesg_with_footer_sob" foo b mesg-with-footer-sob &&
+	pristine_detach initial &&
+	test_commit conflicting unrelated
+'
+
+test_expect_success 'cherry-pick -s inserts blank line after one line subject' '
+	pristine_detach initial &&
+	git cherry-pick -s mesg-one-line &&
+	cat <<-EOF >expect &&
+		$mesg_one_line
+
+		Signed-off-by: $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>
+	EOF
+	git log -1 --pretty=format:%B >actual &&
+	test_cmp expect actual
+'
+
+test_expect_failure 'cherry-pick -s inserts blank line after non-conforming footer' '
+	pristine_detach initial &&
+	git cherry-pick -s mesg-broken-footer &&
+	cat <<-EOF >expect &&
+		$mesg_broken_footer
+
+		Signed-off-by: $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>
+	EOF
+	git log -1 --pretty=format:%B >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'cherry-pick -s inserts blank line when conforming footer not found' '
+	pristine_detach initial &&
+	git cherry-pick -s mesg-no-footer &&
+	cat <<-EOF >expect &&
+		$mesg_no_footer
+
+		Signed-off-by: $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>
+	EOF
+	git log -1 --pretty=format:%B >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'cherry-pick -s adds sob when last sob doesnt match committer' '
+	pristine_detach initial &&
+	git cherry-pick -s mesg-with-footer &&
+	cat <<-EOF >expect &&
+		$mesg_with_footer
+		Signed-off-by: $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL>
+	EOF
+	git log -1 --pretty=format:%B >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'cherry-pick -s refrains from adding duplicate trailing sob' '
+	pristine_detach initial &&
+	git cherry-pick -s mesg-with-footer-sob &&
+	cat <<-EOF >expect &&
+		$mesg_with_footer_sob
+	EOF
+	git log -1 --pretty=format:%B >actual &&
+	test_cmp expect actual
+'
+
+test_done