list-objects-filter: disable 'sparse:path' filters

If someone wants to use as a filter a sparse file that is in the
repository, something like "--filter=sparse:oid=<ref>:<path>"
already works.

So 'sparse:path' is only interesting if the sparse file is not in
the repository. In this case though the current implementation has
a big security issue, as it makes it possible to ask the server to
read any file, like for example /etc/password, and to explore the
filesystem, as well as individual lines of files.

If someone is interested in using a sparse file that is not in the
repository as a filter, then at the minimum a config option, such
as "uploadpack.sparsePathFilter", should be implemented first to
restrict the directory from which the files specified by
'sparse:path' can be read.

For now though, let's just disable 'sparse:path' filters.

Helped-by: Matthew DeVore <matvore@google.com>
Helped-by: Jeff Hostetler <git@jeffhostetler.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 13 insertions, 26 deletions

diff --git a/t/t6112-rev-list-filters-objects.sh b/t/t6112-rev-list-filters-objects.sh
index 9c11427719..acd7f5ab80 100755
--- a/t/t6112-rev-list-filters-objects.sh
+++ b/t/t6112-rev-list-filters-objects.sh
@@ -157,6 +157,10 @@ test_expect_success 'verify blob:limit=1m' '
 '
 
 # Test sparse:path=<path> filter.
+# !!!!
+# NOTE: sparse:path filter support has been dropped for security reasons,
+# so the tests have been changed to make sure that using it fails.
+# !!!!
 # Use a local file containing a sparse-checkout specification to filter
 # out blobs not required for the corresponding sparse-checkout.  We do not
 # require sparse-checkout to actually be enabled.
@@ -176,37 +180,20 @@ test_expect_success 'setup r3' '
 	echo sparse1 >pattern2
 '
 
-test_expect_success 'verify sparse:path=pattern1 omits top-level files' '
-	git -C r3 ls-files -s sparse1 sparse2 >ls_files_result &&
-	awk -f print_2.awk ls_files_result |
-	sort >expected &&
-
-	git -C r3 rev-list --quiet --objects --filter-print-omitted \
-		--filter=sparse:path=../pattern1 HEAD >revs &&
-	awk -f print_1.awk revs |
-	sed "s/~//" |
-	sort >observed &&
-
-	test_cmp expected observed
+test_expect_success 'verify sparse:path=pattern1 fails' '
+	test_must_fail git -C r3 rev-list --quiet --objects \
+		--filter-print-omitted --filter=sparse:path=../pattern1 HEAD
 '
 
-test_expect_success 'verify sparse:path=pattern2 omits both sparse2 files' '
-	git -C r3 ls-files -s sparse2 dir1/sparse2 >ls_files_result &&
-	awk -f print_2.awk ls_files_result |
-	sort >expected &&
-
-	git -C r3 rev-list --quiet --objects --filter-print-omitted \
-		--filter=sparse:path=../pattern2 HEAD >revs &&
-	awk -f print_1.awk revs |
-	sed "s/~//" |
-	sort >observed &&
-
-	test_cmp expected observed
+test_expect_success 'verify sparse:path=pattern2 fails' '
+	test_must_fail git -C r3 rev-list --quiet --objects \
+		--filter-print-omitted --filter=sparse:path=../pattern2 HEAD
 '
 
 # Test sparse:oid=<oid-ish> filter.
-# Like sparse:path, but we get the sparse-checkout specification from
-# a blob rather than a file on disk.
+# Use a blob containing a sparse-checkout specification to filter
+# out blobs not required for the corresponding sparse-checkout.  We do not
+# require sparse-checkout to actually be enabled.
 
 test_expect_success 'setup r3 part 2' '
 	echo dir1/ >r3/pattern &&