receive-pack: allow a maximum input size to be specified

Receive-pack feeds its input to either index-pack or
unpack-objects, which will happily accept as many bytes as
a sender is willing to provide. Let's allow an arbitrary
cutoff point where we will stop writing bytes to disk.

Cleaning up what has already been written to disk is a
related problem that is not addressed by this patch.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 55 insertions, 0 deletions

diff --git a/t/t5546-receive-limits.sh b/t/t5546-receive-limits.sh
new file mode 100755
index 000000000..10cb0be2b
--- /dev/null
+++ b/t/t5546-receive-limits.sh
@@ -0,0 +1,55 @@
+#!/bin/sh
+
+test_description='check receive input limits'
+. ./test-lib.sh
+
+# Let's run tests with different unpack limits: 1 and 10000
+# When the limit is 1, `git receive-pack` will call `git index-pack`.
+# When the limit is 10000, `git receive-pack` will call `git unpack-objects`.
+
+test_pack_input_limit () {
+	case "$1" in
+	index) unpack_limit=1 ;;
+	unpack) unpack_limit=10000 ;;
+	esac
+
+	test_expect_success 'prepare destination repository' '
+		rm -fr dest &&
+		git --bare init dest
+	'
+
+	test_expect_success "set unpacklimit to $unpack_limit" '
+		git --git-dir=dest config receive.unpacklimit "$unpack_limit"
+	'
+
+	test_expect_success 'setting receive.maxInputSize to 512 rejects push' '
+		git --git-dir=dest config receive.maxInputSize 512 &&
+		test_must_fail git push dest HEAD
+	'
+
+	test_expect_success 'bumping limit to 4k allows push' '
+		git --git-dir=dest config receive.maxInputSize 4k &&
+		git push dest HEAD
+	'
+
+	test_expect_success 'prepare destination repository (again)' '
+		rm -fr dest &&
+		git --bare init dest
+	'
+
+	test_expect_success 'lifting the limit allows push' '
+		git --git-dir=dest config receive.maxInputSize 0 &&
+		git push dest HEAD
+	'
+}
+
+test_expect_success "create known-size (1024 bytes) commit" '
+	test-genrandom foo 1024 >one-k &&
+	git add one-k &&
+	test_commit one-k
+'
+
+test_pack_input_limit index
+test_pack_input_limit unpack
+
+test_done