config: let feature.experimental imply gc.cruftPacks=true

We are interested in exploring whether gc.cruftPacks=true should become
the default value.

To determine whether it is safe to do so, let's encourage more users to
try it out.

Users who have set feature.experimental=true have already volunteered to
try new and possibly-breaking config changes, so let's try this new
default with that set of users.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/t/t6500-gc.sh b/t/t6500-gc.sh
index 928a522194..d9acb63951 100755
--- a/t/t6500-gc.sh
+++ b/t/t6500-gc.sh
@@ -221,6 +221,11 @@ assert_cruft_packs () {
 	done <packs
 }
 
+assert_no_cruft_packs () {
+	find .git/objects/pack -name "*.mtimes" >mtimes &&
+	test_must_be_empty mtimes
+}
+
 test_expect_success 'gc --cruft generates a cruft pack' '
 	test_when_finished "rm -fr crufts" &&
 	git init crufts &&
@@ -245,6 +250,54 @@ test_expect_success 'gc.cruftPacks=true generates a cruft pack' '
 	)
 '
 
+test_expect_success 'feature.experimental=true generates a cruft pack' '
+	git init crufts &&
+	test_when_finished "rm -fr crufts" &&
+	(
+		cd crufts &&
+
+		prepare_cruft_history &&
+		git -c feature.experimental=true gc &&
+		assert_cruft_packs
+	)
+'
+
+test_expect_success 'feature.experimental=false allows explicit cruft packs' '
+	git init crufts &&
+	test_when_finished "rm -fr crufts" &&
+	(
+		cd crufts &&
+
+		prepare_cruft_history &&
+		git -c gc.cruftPacks=true -c feature.experimental=false gc &&
+		assert_cruft_packs
+	)
+'
+
+test_expect_success 'feature.experimental=true can be overridden' '
+	git init crufts &&
+	test_when_finished "rm -fr crufts" &&
+	(
+		cd crufts &&
+
+		prepare_cruft_history &&
+		git -c feature.expiremental=true -c gc.cruftPacks=false gc &&
+		assert_no_cruft_packs
+	)
+'
+
+test_expect_success 'feature.experimental=false avoids cruft packs by default' '
+	git init crufts &&
+	test_when_finished "rm -fr crufts" &&
+	(
+		cd crufts &&
+
+		prepare_cruft_history &&
+		git -c feature.experimental=false gc &&
+		assert_no_cruft_packs
+	)
+'
+
 run_and_wait_for_auto_gc () {
 	# We read stdout from gc for the side effect of waiting until the
 	# background gc process exits, closing its fd 9.  Furthermore, the