bisect: add tests for the --no-checkout option.

These tests verify that git-bisect --no-checkout can successfully
bisect commit histories that reference damaged trees.
Signed-off-by: NJon Seymour <jon.seymour@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

t/t6030-bisect-porcelain.sh

@@ -126,6 +126,18 @@ test_expect_success 'bisect reset removes packed refs' '
 	test -z "$(git for-each-ref "refs/heads/bisect")"
 '
 
+test_expect_success 'bisect reset removes bisect state after --no-checkout' '
+	git bisect reset &&
+	git bisect start --no-checkout &&
+	git bisect good $HASH1 &&
+	git bisect bad $HASH3 &&
+	git bisect next &&
+	git bisect reset &&
+	test -z "$(git for-each-ref "refs/bisect/*")" &&
+	test -z "$(git for-each-ref "refs/heads/bisect")" &&
+	test -z "$(git for-each-ref "BISECT_HEAD")"
+'
+
 test_expect_success 'bisect start: back in good branch' '
 	git branch > branch.output &&
 	grep "* other" branch.output > /dev/null &&
@@ -630,4 +642,74 @@ test_expect_success 'bisect fails if tree is broken on trial commit' '
 	test_cmp expected.missing-tree.default error.txt
 '
 
+check_same()
+{
+	echo "Checking $1 is the same as $2" &&
+	git rev-parse "$1" > expected.same &&
+	git rev-parse "$2" > expected.actual &&
+	test_cmp expected.same expected.actual
+}
+
+test_expect_success 'bisect: --no-checkout - start commit bad' '
+	git bisect reset &&
+	git bisect start BROKEN_HASH7 BROKEN_HASH4 --no-checkout &&
+	check_same BROKEN_HASH6 BISECT_HEAD &&
+	git bisect reset
+'
+
+test_expect_success 'bisect: --no-checkout - trial commit bad' '
+	git bisect reset &&
+	git bisect start broken BROKEN_HASH4 --no-checkout &&
+	check_same BROKEN_HASH6 BISECT_HEAD &&
+	git bisect reset
+'
+
+test_expect_success 'bisect: --no-checkout - target before breakage' '
+	git bisect reset &&
+	git bisect start broken BROKEN_HASH4 --no-checkout &&
+	check_same BROKEN_HASH6 BISECT_HEAD &&
+	git bisect bad BISECT_HEAD &&
+	check_same BROKEN_HASH5 BISECT_HEAD &&
+	git bisect bad BISECT_HEAD &&
+	check_same BROKEN_HASH5 bisect/bad &&
+	git bisect reset
+'
+
+test_expect_success 'bisect: --no-checkout - target in breakage' '
+	git bisect reset &&
+	git bisect start broken BROKEN_HASH4 --no-checkout &&
+	check_same BROKEN_HASH6 BISECT_HEAD &&
+	git bisect bad BISECT_HEAD &&
+	check_same BROKEN_HASH5 BISECT_HEAD &&
+	git bisect good BISECT_HEAD &&
+	check_same BROKEN_HASH6 bisect/bad &&
+	git bisect reset
+'
+
+test_expect_success 'bisect: --no-checkout - target after breakage' '
+	git bisect reset &&
+	git bisect start broken BROKEN_HASH4 --no-checkout &&
+	check_same BROKEN_HASH6 BISECT_HEAD &&
+	git bisect good BISECT_HEAD &&
+	check_same BROKEN_HASH8 BISECT_HEAD &&
+	git bisect good BISECT_HEAD &&
+	check_same BROKEN_HASH9 bisect/bad &&
+	git bisect reset
+'
+
+test_expect_success 'bisect: demonstrate identification of damage boundary' "
+	git bisect reset &&
+	git checkout broken &&
+	git bisect start broken master --no-checkout &&
+	git bisect run sh -c '
+		GOOD=\$(git for-each-ref \"--format=%(objectname)\" refs/bisect/good-*) &&
+		git rev-list --objects BISECT_HEAD --not \$GOOD >tmp.\$\$ &&
+		git pack-objects --stdout >/dev/null < tmp.\$\$
+		rc=\$?
+		rm -f tmp.\$\$
+		test \$rc = 0' &&
+	check_same BROKEN_HASH6 bisect/bad &&
+	git bisect reset
+"
+
 test_done