bundle: create filtered bundles

A previous change allowed Git to parse bundles with the 'filter'
capability. Now, teach Git to create bundles with this option.

Some rearranging of code is required to get the option parsing in the
correct spot. There are now two reasons why we might need capabilities
(a new hash algorithm or an object filter) so that is pulled out into a
place where we can check both at the same time.

The --filter option is parsed as part of setup_revisions(), but it
expected the --objects flag, too. That flag is somewhat implied by 'git
bundle' because it creates a pack-file walking objects, but there is
also a walk that walks the revision range expecting only commits. Make
this parsing work by setting 'revs.tree_objects' and 'revs.blob_objects'
before the call to setup_revisions().

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 48 insertions, 0 deletions

diff --git a/t/t6020-bundle-misc.sh b/t/t6020-bundle-misc.sh
index df5ff561fa..6e97c044ee 100755
--- a/t/t6020-bundle-misc.sh
+++ b/t/t6020-bundle-misc.sh
@@ -487,4 +487,52 @@ test_expect_success 'unfiltered bundle with --objects' '
 	test_cmp expect actual
 '
 
+for filter in "blob:none" "tree:0" "tree:1" "blob:limit=100"
+do
+	test_expect_success "filtered bundle: $filter" '
+		test_when_finished rm -rf .git/objects/pack cloned unbundled &&
+		git bundle create partial.bdl \
+			--all \
+			--filter=$filter &&
+
+		git bundle verify partial.bdl >unfiltered &&
+		make_user_friendly_and_stable_output <unfiltered >actual &&
+
+		cat >expect <<-EOF &&
+		The bundle contains these 10 refs:
+		<COMMIT-P> refs/heads/main
+		<COMMIT-N> refs/heads/release
+		<COMMIT-D> refs/heads/topic/1
+		<COMMIT-H> refs/heads/topic/2
+		<COMMIT-D> refs/pull/1/head
+		<COMMIT-G> refs/pull/2/head
+		<TAG-1> refs/tags/v1
+		<TAG-2> refs/tags/v2
+		<TAG-3> refs/tags/v3
+		<COMMIT-P> HEAD
+		The bundle uses this filter: $filter
+		The bundle records a complete history.
+		EOF
+		test_cmp expect actual &&
+
+		test_config uploadpack.allowfilter 1 &&
+		test_config uploadpack.allowanysha1inwant 1 &&
+		git clone --no-local --filter=$filter --bare "file://$(pwd)" cloned &&
+
+		git init unbundled &&
+		git -C unbundled bundle unbundle ../partial.bdl >ref-list.txt &&
+
+		# Count the same number of reachable objects.
+		reflist=$(git for-each-ref --format="%(objectname)") &&
+		git rev-list --objects --filter=$filter --missing=allow-any \
+			$reflist >expect &&
+		for repo in cloned unbundled
+		do
+			git -C $repo rev-list --objects --missing=allow-any \
+				$reflist >actual &&
+			test_cmp expect actual || return 1
+		done
+	'
+done
+
 test_done