[PATCH v2] test: add test for git bisect skip with --term* arguments

[Bagas Sanjaya <bagasdotme@gmail.com>]

Trygve Aaberge reported the current git bisect breakage on [1].
After starting bisection with --term-new and --term-old arguments to git
bisect start, skipping with git bisect skip does not change HEAD as
expected.

Let's add the test to catch this breakage.

[1]: https://lore.kernel.org/git/20210418151459.GC10839@aaberge.net/

Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
---

Changes from v1:
  * style changes requested by Junio
  * rename test script and edit test description to be more descriptive
  * remove exec </dev/null (I don't know what it means)
  * repo initialization is now on test_expect_success block (as
    requested by Junio)
  
 t/t6031-bisect-skip-with-term.sh | 36 ++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100755 t/t6031-bisect-skip-with-term.sh

diff --git a/t/t6031-bisect-skip-with-term.sh b/t/t6031-bisect-skip-with-term.sh
new file mode 100755
index 0000000000..f1e1c4c1a2
--- /dev/null
+++ b/t/t6031-bisect-skip-with-term.sh
@@ -0,0 +1,36 @@
+#!/bin/sh
+
+#
+# Copyright (c) 2021 Bagas Sanjaya
+#
+
+test_description='Tests skipping bisect which the bisection is started with --term* arguments'
+
+GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
+export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
+
+. ./test-lib.sh
+
+# hash variables to be used in bisection test
+HASH_SKIPPED_FROM=
+HASH_SKIPPED_TO=
+
+# test repo initialization
+test_expect_success 'initialize testing repo with 20 commits' '
+	for i in $(test_seq 1 20); do
+		echo $i >>test &&
+		git add test && git commit -m "commit $i" &&
+		test_tick
+	done
+'
+
+# actual bisection test
+test_expect_success 'test moving HEAD when skip bisecting' '
+	git bisect start --term-new=ok --term-old=whoops HEAD HEAD~9 &&
+	HASH_SKIPPED_FROM=$(git rev-parse --verify HEAD) &&
+	git bisect skip &&
+	HASH_SKIPPED_TO=$(git rev-parse --verify HEAD) &&
+	test $HASH_SKIPPED_FROM != $HASH_SKIPPED_TO
+'
+
+test_done

base-commit: b0c09ab8796fb736efa432b8e817334f3e5ee75a
-- 
2.25.1