merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 39 insertions, 3 deletions

diff --git a/third_party/git/t/t5300-pack-object.sh b/third_party/git/t/t5300-pack-object.sh
index 410a09b0dd75..392201cabdfe 100755
--- a/third_party/git/t/t5300-pack-object.sh
+++ b/third_party/git/t/t5300-pack-object.sh
@@ -412,18 +412,18 @@ test_expect_success 'set up pack for non-repo tests' '
 '
 
 test_expect_success 'index-pack --stdin complains of non-repo' '
-	nongit test_must_fail git index-pack --stdin <foo.pack &&
+	nongit test_must_fail git index-pack --object-format=$(test_oid algo) --stdin <foo.pack &&
 	test_path_is_missing non-repo/.git
 '
 
 test_expect_success 'index-pack <pack> works in non-repo' '
-	nongit git index-pack ../foo.pack &&
+	nongit git index-pack --object-format=$(test_oid algo) ../foo.pack &&
 	test_path_is_file foo.idx
 '
 
 test_expect_success 'index-pack --strict <pack> works in non-repo' '
 	rm -f foo.idx &&
-	nongit git index-pack --strict ../foo.pack &&
+	nongit git index-pack --strict --object-format=$(test_oid algo) ../foo.pack &&
 	test_path_is_file foo.idx
 '
 
@@ -496,4 +496,40 @@ test_expect_success 'make sure index-pack detects the SHA1 collision (large blob
 	)
 '
 
+test_expect_success 'prefetch objects' '
+	rm -rf server client &&
+
+	git init server &&
+	test_config -C server uploadpack.allowanysha1inwant 1 &&
+	test_config -C server uploadpack.allowfilter 1 &&
+	test_config -C server protocol.version 2 &&
+
+	echo one >server/one &&
+	git -C server add one &&
+	git -C server commit -m one &&
+	git -C server branch one_branch &&
+
+	echo two_a >server/two_a &&
+	echo two_b >server/two_b &&
+	git -C server add two_a two_b &&
+	git -C server commit -m two &&
+
+	echo three >server/three &&
+	git -C server add three &&
+	git -C server commit -m three &&
+	git -C server branch three_branch &&
+
+	# Clone, fetch "two" with blobs excluded, and re-push it. This requires
+	# the client to have the blobs of "two" - verify that these are
+	# prefetched in one batch.
+	git clone --filter=blob:none --single-branch -b one_branch \
+		"file://$(pwd)/server" client &&
+	test_config -C client protocol.version 2 &&
+	TWO=$(git -C server rev-parse three_branch^) &&
+	git -C client fetch --filter=blob:none origin "$TWO" &&
+	GIT_TRACE_PACKET=$(pwd)/trace git -C client push origin "$TWO":refs/heads/two_branch &&
+	grep "fetch> done" trace >donelines &&
+	test_line_count = 1 donelines
+'
+
 test_done