1 files changed, 121 insertions, 1 deletions
diff --git a/t/t5331-pack-objects-stdin.sh b/t/t5331-pack-objects-stdin.sh
index b48c0cbe8f..4a8df5a389 100755
--- a/t/t5331-pack-objects-stdin.sh
+++ b/t/t5331-pack-objects-stdin.sh
@@ -64,7 +64,7 @@ test_expect_success '--stdin-packs is incompatible with --filter' '
 		cd stdin-packs &&
 		test_must_fail git pack-objects --stdin-packs --stdout \
 			--filter=blob:none </dev/null 2>err &&
-		test_grep "cannot use --filter with --stdin-packs" err
+		test_grep "options .--stdin-packs. and .--filter. cannot be used together" err
 	)
 '
 
@@ -236,4 +236,124 @@ test_expect_success 'pack-objects --stdin with packfiles from main and alternate
 	test_cmp expected-objects actual-objects
 '
 
+objdir=.git/objects
+packdir=$objdir/pack
+
+objects_in_packs () {
+	for p in "$@"
+	do
+		git show-index <"$packdir/pack-$p.idx" || return 1
+	done >objects.raw &&
+
+	cut -d' ' -f2 objects.raw | sort &&
+	rm -f objects.raw
+}
+
+test_expect_success '--stdin-packs=follow walks into unknown packs' '
+	test_when_finished "rm -fr repo" &&
+
+	git init repo &&
+	(
+		cd repo &&
+
+		for c in A B C D
+		do
+			test_commit "$c" || return 1
+		done &&
+
+		A="$(echo A | git pack-objects --revs $packdir/pack)" &&
+		B="$(echo A..B | git pack-objects --revs $packdir/pack)" &&
+		C="$(echo B..C | git pack-objects --revs $packdir/pack)" &&
+		D="$(echo C..D | git pack-objects --revs $packdir/pack)" &&
+		test_commit E &&
+
+		git prune-packed &&
+
+		cat >in <<-EOF &&
+		pack-$B.pack
+		^pack-$C.pack
+		pack-$D.pack
+		EOF
+
+		# With just --stdin-packs, pack "A" is unknown to us, so
+		# only objects from packs "B" and "D" are included in
+		# the output pack.
+		P=$(git pack-objects --stdin-packs $packdir/pack <in) &&
+		objects_in_packs $B $D >expect &&
+		objects_in_packs $P >actual &&
+		test_cmp expect actual &&
+
+		# But with --stdin-packs=follow, objects from both
+		# included packs reach objects from the unknown pack, so
+		# objects from pack "A" is included in the output pack
+		# in addition to the above.
+		P=$(git pack-objects --stdin-packs=follow $packdir/pack <in) &&
+		objects_in_packs $A $B $D >expect &&
+		objects_in_packs $P >actual &&
+		test_cmp expect actual &&
+
+		# And with --unpacked, we will pick up objects from unknown
+		# packs that are reachable from loose objects. Loose object E
+		# reaches objects in pack A, but there are three excluded packs
+		# in between.
+		#
+		# The resulting pack should include objects reachable from E
+		# that are not present in packs B, C, or D, along with those
+		# present in pack A.
+		cat >in <<-EOF &&
+		^pack-$B.pack
+		^pack-$C.pack
+		^pack-$D.pack
+		EOF
+
+		P=$(git pack-objects --stdin-packs=follow --unpacked \
+			$packdir/pack <in) &&
+
+		{
+			objects_in_packs $A &&
+			git rev-list --objects --no-object-names D..E
+		}>expect.raw &&
+		sort expect.raw >expect &&
+		objects_in_packs $P >actual &&
+		test_cmp expect actual
+	)
+'
+
+stdin_packs__follow_with_only () {
+	rm -fr stdin_packs__follow_with_only &&
+	git init stdin_packs__follow_with_only &&
+	(
+		cd stdin_packs__follow_with_only &&
+
+		test_commit A &&
+		test_commit B &&
+
+		git rev-parse "$@" >B.objects &&
+
+		echo A | git pack-objects --revs $packdir/pack &&
+		B="$(git pack-objects $packdir/pack <B.objects)" &&
+
+		git cat-file --batch-check="%(objectname)" --batch-all-objects >objs &&
+		for obj in $(cat objs)
+		do
+			rm -f $objdir/$(test_oid_to_path $obj) || return 1
+		done &&
+
+		( cd $packdir && ls pack-*.pack ) >in &&
+		git pack-objects --stdin-packs=follow --stdout >/dev/null <in
+	)
+}
+
+test_expect_success '--stdin-packs=follow tolerates missing blobs' '
+	stdin_packs__follow_with_only HEAD HEAD^{tree}
+'
+
+test_expect_success '--stdin-packs=follow tolerates missing trees' '
+	stdin_packs__follow_with_only HEAD HEAD:B.t
+'
+
+test_expect_success '--stdin-packs=follow tolerates missing commits' '
+	stdin_packs__follow_with_only HEAD HEAD^{tree}
+'
+
 test_done