[PATCH v3 3/3] patch-id-test: test --stable and --unstable flags

["Michael S. Tsirkin" <mst@redhat.com>]

Verify that patch ID is now stable against diff split and reordering.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---

Changes from v2:
	added test to verify patch ID is stable against diff splitting

 t/t4204-patch-id.sh | 117 ++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 109 insertions(+), 8 deletions(-)

diff --git a/t/t4204-patch-id.sh b/t/t4204-patch-id.sh
index d2c930d..1679714 100755
--- a/t/t4204-patch-id.sh
+++ b/t/t4204-patch-id.sh
@@ -5,12 +5,46 @@ test_description='git patch-id'
 . ./test-lib.sh
 
 test_expect_success 'setup' '
-	test_commit initial foo a &&
-	test_commit first foo b &&
-	git checkout -b same HEAD^ &&
-	test_commit same-msg foo b &&
-	git checkout -b notsame HEAD^ &&
-	test_commit notsame-msg foo c
+	cat > a <<-\EOF &&
+		a
+		a
+		a
+		a
+		a
+		a
+		a
+		a
+		EOF
+	(cat a; echo b) > ab &&
+	(echo d; cat a; echo b) > dab &&
+	cp a foo &&
+	cp a bar &&
+	git add foo bar &&
+	git commit -a -m initial &&
+	cp ab foo &&
+	cp ab bar &&
+	git commit -a -m first &&
+	git checkout -b same master &&
+	git commit --amend -m same-msg &&
+	git checkout -b notsame master &&
+	echo c > foo &&
+	echo c > bar &&
+	git commit --amend -a -m notsame-msg &&
+	git checkout -b split master &&
+	cp dab foo &&
+	cp dab bar &&
+	git commit -a -m split &&
+	git checkout -b merged master &&
+	git checkout split -- foo bar &&
+	git commit --amend -a -m merged &&
+	cat > bar-then-foo <<-\EOF &&
+		bar
+		foo
+		EOF
+	cat > foo-then-bar <<-\EOF
+		foo
+		bar
+		EOF
 '
 
 test_expect_success 'patch-id output is well-formed' '
@@ -23,11 +57,33 @@ calc_patch_id () {
 		sed "s# .*##" > patch-id_"$1"
 }
 
+calc_patch_id_unstable () {
+	git patch-id --unstable |
+		sed "s# .*##" > patch-id_"$1"
+}
+
+calc_patch_id_stable () {
+	git patch-id --stable |
+		sed "s# .*##" > patch-id_"$1"
+}
+
+
 get_patch_id () {
-	git log -p -1 "$1" | git patch-id |
+	git log -p -1 "$1" -O bar-then-foo -- | git patch-id |
 		sed "s# .*##" > patch-id_"$1"
 }
 
+get_patch_id_stable () {
+	git log -p -1 "$1" -O bar-then-foo | git patch-id --stable |
+		sed "s# .*##" > patch-id_"$1"
+}
+
+get_patch_id_unstable () {
+	git log -p -1 "$1" -O bar-then-foo | git patch-id --unstable |
+		sed "s# .*##" > patch-id_"$1"
+}
+
+
 test_expect_success 'patch-id detects equality' '
 	get_patch_id master &&
 	get_patch_id same &&
@@ -52,10 +108,55 @@ test_expect_success 'patch-id supports git-format-patch output' '
 test_expect_success 'whitespace is irrelevant in footer' '
 	get_patch_id master &&
 	git checkout same &&
-	git format-patch -1 --stdout | sed "s/ \$//" | calc_patch_id same &&
+	git format-patch -1 --stdout | sed "s/ \$//" |
+		calc_patch_id same &&
 	test_cmp patch-id_master patch-id_same
 '
 
+test_expect_success 'file order is irrelevant by default' '
+	get_patch_id master &&
+	git checkout same &&
+	git format-patch -1 --stdout -O foo-then-bar |
+		calc_patch_id same &&
+	test_cmp patch-id_master patch-id_same
+'
+
+test_expect_success 'file order is irrelevant with --stable' '
+	get_patch_id_stable master &&
+	git checkout same &&
+	git format-patch -1 --stdout -O foo-then-bar |
+		calc_patch_id_stable same &&
+	test_cmp patch-id_master patch-id_same
+'
+
+test_expect_success 'file order is relevant with --unstable' '
+	get_patch_id_unstable master &&
+	git checkout same &&
+	git format-patch -1 --stdout -O foo-then-bar | calc_patch_id_unstable notsame &&
+	! test_cmp patch-id_master patch-id_notsame
+'
+
+test_expect_success 'splitting patch does not affect id by default' '
+	get_patch_id merged &&
+	(git log -p -1 -O foo-then-bar split~1; git diff split~1..split) |
+		calc_patch_id split &&
+	test_cmp patch-id_merged patch-id_split
+'
+
+test_expect_success 'splitting patch does not affect id with --stable' '
+	get_patch_id_stable merged &&
+	(git log -p -1 -O foo-then-bar split~1; git diff split~1..split) |
+		calc_patch_id_stable split &&
+	test_cmp patch-id_merged patch-id_split
+'
+
+test_expect_success 'splitting patch affects id with --unstable' '
+	get_patch_id_unstable merged &&
+	(git log -p -1 -O foo-then-bar split~1; git diff split~1..split) |
+		calc_patch_id_unstable split &&
+	! test_cmp patch-id_merged patch-id_split
+'
+
 test_expect_success 'patch-id supports git-format-patch MIME output' '
 	get_patch_id master &&
 	git checkout same &&
-- 
MST