merge(third_party/git): Merge squashed git subtree at v2.23.0 r/373

Merge commit '1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5' as 'third_party/git'

1 files changed, 722 insertions, 0 deletions

diff --git a/third_party/git/t/t5526-fetch-submodules.sh b/third_party/git/t/t5526-fetch-submodules.sh
new file mode 100755
index 000000000000..63205dfdf962
--- /dev/null
+++ b/third_party/git/t/t5526-fetch-submodules.sh
@@ -0,0 +1,722 @@
+#!/bin/sh
+# Copyright (c) 2010, Jens Lehmann
+
+test_description='Recursive "git fetch" for submodules'
+
+. ./test-lib.sh
+
+pwd=$(pwd)
+
+add_upstream_commit() {
+	(
+		cd submodule &&
+		head1=$(git rev-parse --short HEAD) &&
+		echo new >> subfile &&
+		test_tick &&
+		git add subfile &&
+		git commit -m new subfile &&
+		head2=$(git rev-parse --short HEAD) &&
+		echo "Fetching submodule submodule" > ../expect.err &&
+		echo "From $pwd/submodule" >> ../expect.err &&
+		echo "   $head1..$head2  master     -> origin/master" >> ../expect.err
+	) &&
+	(
+		cd deepsubmodule &&
+		head1=$(git rev-parse --short HEAD) &&
+		echo new >> deepsubfile &&
+		test_tick &&
+		git add deepsubfile &&
+		git commit -m new deepsubfile &&
+		head2=$(git rev-parse --short HEAD) &&
+		echo "Fetching submodule submodule/subdir/deepsubmodule" >> ../expect.err
+		echo "From $pwd/deepsubmodule" >> ../expect.err &&
+		echo "   $head1..$head2  master     -> origin/master" >> ../expect.err
+	)
+}
+
+test_expect_success setup '
+	mkdir deepsubmodule &&
+	(
+		cd deepsubmodule &&
+		git init &&
+		echo deepsubcontent > deepsubfile &&
+		git add deepsubfile &&
+		git commit -m new deepsubfile
+	) &&
+	mkdir submodule &&
+	(
+		cd submodule &&
+		git init &&
+		echo subcontent > subfile &&
+		git add subfile &&
+		git submodule add "$pwd/deepsubmodule" subdir/deepsubmodule &&
+		git commit -a -m new
+	) &&
+	git submodule add "$pwd/submodule" submodule &&
+	git commit -am initial &&
+	git clone . downstream &&
+	(
+		cd downstream &&
+		git submodule update --init --recursive
+	)
+'
+
+test_expect_success "fetch --recurse-submodules recurses into submodules" '
+	add_upstream_commit &&
+	(
+		cd downstream &&
+		git fetch --recurse-submodules >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err actual.err
+'
+
+test_expect_success "submodule.recurse option triggers recursive fetch" '
+	add_upstream_commit &&
+	(
+		cd downstream &&
+		git -c submodule.recurse fetch >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err actual.err
+'
+
+test_expect_success "fetch --recurse-submodules -j2 has the same output behaviour" '
+	add_upstream_commit &&
+	(
+		cd downstream &&
+		GIT_TRACE="$TRASH_DIRECTORY/trace.out" git fetch --recurse-submodules -j2 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err actual.err &&
+	grep "2 tasks" trace.out
+'
+
+test_expect_success "fetch alone only fetches superproject" '
+	add_upstream_commit &&
+	(
+		cd downstream &&
+		git fetch >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_must_be_empty actual.err
+'
+
+test_expect_success "fetch --no-recurse-submodules only fetches superproject" '
+	(
+		cd downstream &&
+		git fetch --no-recurse-submodules >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_must_be_empty actual.err
+'
+
+test_expect_success "using fetchRecurseSubmodules=true in .gitmodules recurses into submodules" '
+	(
+		cd downstream &&
+		git config -f .gitmodules submodule.submodule.fetchRecurseSubmodules true &&
+		git fetch >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err actual.err
+'
+
+test_expect_success "--no-recurse-submodules overrides .gitmodules config" '
+	add_upstream_commit &&
+	(
+		cd downstream &&
+		git fetch --no-recurse-submodules >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_must_be_empty actual.err
+'
+
+test_expect_success "using fetchRecurseSubmodules=false in .git/config overrides setting in .gitmodules" '
+	(
+		cd downstream &&
+		git config submodule.submodule.fetchRecurseSubmodules false &&
+		git fetch >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_must_be_empty actual.err
+'
+
+test_expect_success "--recurse-submodules overrides fetchRecurseSubmodules setting from .git/config" '
+	(
+		cd downstream &&
+		git fetch --recurse-submodules >../actual.out 2>../actual.err &&
+		git config --unset -f .gitmodules submodule.submodule.fetchRecurseSubmodules &&
+		git config --unset submodule.submodule.fetchRecurseSubmodules
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err actual.err
+'
+
+test_expect_success "--quiet propagates to submodules" '
+	(
+		cd downstream &&
+		git fetch --recurse-submodules --quiet >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_must_be_empty actual.err
+'
+
+test_expect_success "--quiet propagates to parallel submodules" '
+	(
+		cd downstream &&
+		git fetch --recurse-submodules -j 2 --quiet  >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_must_be_empty actual.err
+'
+
+test_expect_success "--dry-run propagates to submodules" '
+	add_upstream_commit &&
+	(
+		cd downstream &&
+		git fetch --recurse-submodules --dry-run >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err actual.err
+'
+
+test_expect_success "Without --dry-run propagates to submodules" '
+	(
+		cd downstream &&
+		git fetch --recurse-submodules >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err actual.err
+'
+
+test_expect_success "recurseSubmodules=true propagates into submodules" '
+	add_upstream_commit &&
+	(
+		cd downstream &&
+		git config fetch.recurseSubmodules true &&
+		git fetch >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err actual.err
+'
+
+test_expect_success "--recurse-submodules overrides config in submodule" '
+	add_upstream_commit &&
+	(
+		cd downstream &&
+		(
+			cd submodule &&
+			git config fetch.recurseSubmodules false
+		) &&
+		git fetch --recurse-submodules >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err actual.err
+'
+
+test_expect_success "--no-recurse-submodules overrides config setting" '
+	add_upstream_commit &&
+	(
+		cd downstream &&
+		git config fetch.recurseSubmodules true &&
+		git fetch --no-recurse-submodules >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_must_be_empty actual.err
+'
+
+test_expect_success "Recursion doesn't happen when no new commits are fetched in the superproject" '
+	(
+		cd downstream &&
+		(
+			cd submodule &&
+			git config --unset fetch.recurseSubmodules
+		) &&
+		git config --unset fetch.recurseSubmodules &&
+		git fetch >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_must_be_empty actual.err
+'
+
+test_expect_success "Recursion stops when no new submodule commits are fetched" '
+	head1=$(git rev-parse --short HEAD) &&
+	git add submodule &&
+	git commit -m "new submodule" &&
+	head2=$(git rev-parse --short HEAD) &&
+	echo "From $pwd/." > expect.err.sub &&
+	echo "   $head1..$head2  master     -> origin/master" >>expect.err.sub &&
+	head -3 expect.err >> expect.err.sub &&
+	(
+		cd downstream &&
+		git fetch >../actual.out 2>../actual.err
+	) &&
+	test_i18ncmp expect.err.sub actual.err &&
+	test_must_be_empty actual.out
+'
+
+test_expect_success "Recursion doesn't happen when new superproject commits don't change any submodules" '
+	add_upstream_commit &&
+	head1=$(git rev-parse --short HEAD) &&
+	echo a > file &&
+	git add file &&
+	git commit -m "new file" &&
+	head2=$(git rev-parse --short HEAD) &&
+	echo "From $pwd/." > expect.err.file &&
+	echo "   $head1..$head2  master     -> origin/master" >> expect.err.file &&
+	(
+		cd downstream &&
+		git fetch >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err.file actual.err
+'
+
+test_expect_success "Recursion picks up config in submodule" '
+	(
+		cd downstream &&
+		git fetch --recurse-submodules &&
+		(
+			cd submodule &&
+			git config fetch.recurseSubmodules true
+		)
+	) &&
+	add_upstream_commit &&
+	head1=$(git rev-parse --short HEAD) &&
+	git add submodule &&
+	git commit -m "new submodule" &&
+	head2=$(git rev-parse --short HEAD) &&
+	echo "From $pwd/." > expect.err.sub &&
+	echo "   $head1..$head2  master     -> origin/master" >> expect.err.sub &&
+	cat expect.err >> expect.err.sub &&
+	(
+		cd downstream &&
+		git fetch >../actual.out 2>../actual.err &&
+		(
+			cd submodule &&
+			git config --unset fetch.recurseSubmodules
+		)
+	) &&
+	test_i18ncmp expect.err.sub actual.err &&
+	test_must_be_empty actual.out
+'
+
+test_expect_success "Recursion picks up all submodules when necessary" '
+	add_upstream_commit &&
+	(
+		cd submodule &&
+		(
+			cd subdir/deepsubmodule &&
+			git fetch &&
+			git checkout -q FETCH_HEAD
+		) &&
+		head1=$(git rev-parse --short HEAD^) &&
+		git add subdir/deepsubmodule &&
+		git commit -m "new deepsubmodule" &&
+		head2=$(git rev-parse --short HEAD) &&
+		echo "Fetching submodule submodule" > ../expect.err.sub &&
+		echo "From $pwd/submodule" >> ../expect.err.sub &&
+		echo "   $head1..$head2  master     -> origin/master" >> ../expect.err.sub
+	) &&
+	head1=$(git rev-parse --short HEAD) &&
+	git add submodule &&
+	git commit -m "new submodule" &&
+	head2=$(git rev-parse --short HEAD) &&
+	echo "From $pwd/." > expect.err.2 &&
+	echo "   $head1..$head2  master     -> origin/master" >> expect.err.2 &&
+	cat expect.err.sub >> expect.err.2 &&
+	tail -3 expect.err >> expect.err.2 &&
+	(
+		cd downstream &&
+		git fetch >../actual.out 2>../actual.err
+	) &&
+	test_i18ncmp expect.err.2 actual.err &&
+	test_must_be_empty actual.out
+'
+
+test_expect_success "'--recurse-submodules=on-demand' doesn't recurse when no new commits are fetched in the superproject (and ignores config)" '
+	add_upstream_commit &&
+	(
+		cd submodule &&
+		(
+			cd subdir/deepsubmodule &&
+			git fetch &&
+			git checkout -q FETCH_HEAD
+		) &&
+		head1=$(git rev-parse --short HEAD^) &&
+		git add subdir/deepsubmodule &&
+		git commit -m "new deepsubmodule" &&
+		head2=$(git rev-parse --short HEAD) &&
+		echo Fetching submodule submodule > ../expect.err.sub &&
+		echo "From $pwd/submodule" >> ../expect.err.sub &&
+		echo "   $head1..$head2  master     -> origin/master" >> ../expect.err.sub
+	) &&
+	(
+		cd downstream &&
+		git config fetch.recurseSubmodules true &&
+		git fetch --recurse-submodules=on-demand >../actual.out 2>../actual.err &&
+		git config --unset fetch.recurseSubmodules
+	) &&
+	test_must_be_empty actual.out &&
+	test_must_be_empty actual.err
+'
+
+test_expect_success "'--recurse-submodules=on-demand' recurses as deep as necessary (and ignores config)" '
+	head1=$(git rev-parse --short HEAD) &&
+	git add submodule &&
+	git commit -m "new submodule" &&
+	head2=$(git rev-parse --short HEAD) &&
+	tail -3 expect.err > expect.err.deepsub &&
+	echo "From $pwd/." > expect.err &&
+	echo "   $head1..$head2  master     -> origin/master" >>expect.err &&
+	cat expect.err.sub >> expect.err &&
+	cat expect.err.deepsub >> expect.err &&
+	(
+		cd downstream &&
+		git config fetch.recurseSubmodules false &&
+		(
+			cd submodule &&
+			git config -f .gitmodules submodule.subdir/deepsubmodule.fetchRecursive false
+		) &&
+		git fetch --recurse-submodules=on-demand >../actual.out 2>../actual.err &&
+		git config --unset fetch.recurseSubmodules &&
+		(
+			cd submodule &&
+			git config --unset -f .gitmodules submodule.subdir/deepsubmodule.fetchRecursive
+		)
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err actual.err
+'
+
+test_expect_success "'--recurse-submodules=on-demand' stops when no new submodule commits are found in the superproject (and ignores config)" '
+	add_upstream_commit &&
+	head1=$(git rev-parse --short HEAD) &&
+	echo a >> file &&
+	git add file &&
+	git commit -m "new file" &&
+	head2=$(git rev-parse --short HEAD) &&
+	echo "From $pwd/." > expect.err.file &&
+	echo "   $head1..$head2  master     -> origin/master" >> expect.err.file &&
+	(
+		cd downstream &&
+		git fetch --recurse-submodules=on-demand >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err.file actual.err
+'
+
+test_expect_success "'fetch.recurseSubmodules=on-demand' overrides global config" '
+	(
+		cd downstream &&
+		git fetch --recurse-submodules
+	) &&
+	add_upstream_commit &&
+	git config --global fetch.recurseSubmodules false &&
+	head1=$(git rev-parse --short HEAD) &&
+	git add submodule &&
+	git commit -m "new submodule" &&
+	head2=$(git rev-parse --short HEAD) &&
+	echo "From $pwd/." > expect.err.2 &&
+	echo "   $head1..$head2  master     -> origin/master" >>expect.err.2 &&
+	head -3 expect.err >> expect.err.2 &&
+	(
+		cd downstream &&
+		git config fetch.recurseSubmodules on-demand &&
+		git fetch >../actual.out 2>../actual.err
+	) &&
+	git config --global --unset fetch.recurseSubmodules &&
+	(
+		cd downstream &&
+		git config --unset fetch.recurseSubmodules
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err.2 actual.err
+'
+
+test_expect_success "'submodule.<sub>.fetchRecurseSubmodules=on-demand' overrides fetch.recurseSubmodules" '
+	(
+		cd downstream &&
+		git fetch --recurse-submodules
+	) &&
+	add_upstream_commit &&
+	git config fetch.recurseSubmodules false &&
+	head1=$(git rev-parse --short HEAD) &&
+	git add submodule &&
+	git commit -m "new submodule" &&
+	head2=$(git rev-parse --short HEAD) &&
+	echo "From $pwd/." > expect.err.2 &&
+	echo "   $head1..$head2  master     -> origin/master" >>expect.err.2 &&
+	head -3 expect.err >> expect.err.2 &&
+	(
+		cd downstream &&
+		git config submodule.submodule.fetchRecurseSubmodules on-demand &&
+		git fetch >../actual.out 2>../actual.err
+	) &&
+	git config --unset fetch.recurseSubmodules &&
+	(
+		cd downstream &&
+		git config --unset submodule.submodule.fetchRecurseSubmodules
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err.2 actual.err
+'
+
+test_expect_success "don't fetch submodule when newly recorded commits are already present" '
+	(
+		cd submodule &&
+		git checkout -q HEAD^^
+	) &&
+	head1=$(git rev-parse --short HEAD) &&
+	git add submodule &&
+	git commit -m "submodule rewound" &&
+	head2=$(git rev-parse --short HEAD) &&
+	echo "From $pwd/." > expect.err &&
+	echo "   $head1..$head2  master     -> origin/master" >> expect.err &&
+	(
+		cd downstream &&
+		git fetch >../actual.out 2>../actual.err
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err actual.err &&
+	(
+		cd submodule &&
+		git checkout -q master
+	)
+'
+
+test_expect_success "'fetch.recurseSubmodules=on-demand' works also without .gitmodules entry" '
+	(
+		cd downstream &&
+		git fetch --recurse-submodules
+	) &&
+	add_upstream_commit &&
+	head1=$(git rev-parse --short HEAD) &&
+	git add submodule &&
+	git rm .gitmodules &&
+	git commit -m "new submodule without .gitmodules" &&
+	head2=$(git rev-parse --short HEAD) &&
+	echo "From $pwd/." >expect.err.2 &&
+	echo "   $head1..$head2  master     -> origin/master" >>expect.err.2 &&
+	head -3 expect.err >>expect.err.2 &&
+	(
+		cd downstream &&
+		rm .gitmodules &&
+		git config fetch.recurseSubmodules on-demand &&
+		# fake submodule configuration to avoid skipping submodule handling
+		git config -f .gitmodules submodule.fake.path fake &&
+		git config -f .gitmodules submodule.fake.url fakeurl &&
+		git add .gitmodules &&
+		git config --unset submodule.submodule.url &&
+		git fetch >../actual.out 2>../actual.err &&
+		# cleanup
+		git config --unset fetch.recurseSubmodules &&
+		git reset --hard
+	) &&
+	test_must_be_empty actual.out &&
+	test_i18ncmp expect.err.2 actual.err &&
+	git checkout HEAD^ -- .gitmodules &&
+	git add .gitmodules &&
+	git commit -m "new submodule restored .gitmodules"
+'
+
+test_expect_success 'fetching submodules respects parallel settings' '
+	git config fetch.recurseSubmodules true &&
+	(
+		cd downstream &&
+		GIT_TRACE=$(pwd)/trace.out git fetch &&
+		grep "1 tasks" trace.out &&
+		GIT_TRACE=$(pwd)/trace.out git fetch --jobs 7 &&
+		grep "7 tasks" trace.out &&
+		git config submodule.fetchJobs 8 &&
+		GIT_TRACE=$(pwd)/trace.out git fetch &&
+		grep "8 tasks" trace.out &&
+		GIT_TRACE=$(pwd)/trace.out git fetch --jobs 9 &&
+		grep "9 tasks" trace.out
+	)
+'
+
+test_expect_success 'fetching submodule into a broken repository' '
+	# Prepare src and src/sub nested in it
+	git init src &&
+	(
+		cd src &&
+		git init sub &&
+		git -C sub commit --allow-empty -m "initial in sub" &&
+		git submodule add -- ./sub sub &&
+		git commit -m "initial in top"
+	) &&
+
+	# Clone the old-fashoned way
+	git clone src dst &&
+	git -C dst clone ../src/sub sub &&
+
+	# Make sure that old-fashoned layout is still supported
+	git -C dst status &&
+
+	# "diff" would find no change
+	git -C dst diff --exit-code &&
+
+	# Recursive-fetch works fine
+	git -C dst fetch --recurse-submodules &&
+
+	# Break the receiving submodule
+	rm -f dst/sub/.git/HEAD &&
+
+	# NOTE: without the fix the following tests will recurse forever!
+	# They should terminate with an error.
+
+	test_must_fail git -C dst status &&
+	test_must_fail git -C dst diff &&
+	test_must_fail git -C dst fetch --recurse-submodules
+'
+
+test_expect_success "fetch new commits when submodule got renamed" '
+	git clone . downstream_rename &&
+	(
+		cd downstream_rename &&
+		git submodule update --init --recursive &&
+		git checkout -b rename &&
+		git mv submodule submodule_renamed &&
+		(
+			cd submodule_renamed &&
+			git checkout -b rename_sub &&
+			echo a >a &&
+			git add a &&
+			git commit -ma &&
+			git push origin rename_sub &&
+			git rev-parse HEAD >../../expect
+		) &&
+		git add submodule_renamed &&
+		git commit -m "update renamed submodule" &&
+		git push origin rename
+	) &&
+	(
+		cd downstream &&
+		git fetch --recurse-submodules=on-demand &&
+		(
+			cd submodule &&
+			git rev-parse origin/rename_sub >../../actual
+		)
+	) &&
+	test_cmp expect actual
+'
+
+test_expect_success "fetch new submodule commits on-demand outside standard refspec" '
+	# add a second submodule and ensure it is around in downstream first
+	git clone submodule sub1 &&
+	git submodule add ./sub1 &&
+	git commit -m "adding a second submodule" &&
+	git -C downstream pull &&
+	git -C downstream submodule update --init --recursive &&
+
+	git checkout --detach &&
+
+	C=$(git -C submodule commit-tree -m "new change outside refs/heads" HEAD^{tree}) &&
+	git -C submodule update-ref refs/changes/1 $C &&
+	git update-index --cacheinfo 160000 $C submodule &&
+	test_tick &&
+
+	D=$(git -C sub1 commit-tree -m "new change outside refs/heads" HEAD^{tree}) &&
+	git -C sub1 update-ref refs/changes/2 $D &&
+	git update-index --cacheinfo 160000 $D sub1 &&
+
+	git commit -m "updated submodules outside of refs/heads" &&
+	E=$(git rev-parse HEAD) &&
+	git update-ref refs/changes/3 $E &&
+	(
+		cd downstream &&
+		git fetch --recurse-submodules origin refs/changes/3:refs/heads/my_branch &&
+		git -C submodule cat-file -t $C &&
+		git -C sub1 cat-file -t $D &&
+		git checkout --recurse-submodules FETCH_HEAD
+	)
+'
+
+test_expect_success 'fetch new submodule commit on-demand in FETCH_HEAD' '
+	# depends on the previous test for setup
+
+	C=$(git -C submodule commit-tree -m "another change outside refs/heads" HEAD^{tree}) &&
+	git -C submodule update-ref refs/changes/4 $C &&
+	git update-index --cacheinfo 160000 $C submodule &&
+	test_tick &&
+
+	D=$(git -C sub1 commit-tree -m "another change outside refs/heads" HEAD^{tree}) &&
+	git -C sub1 update-ref refs/changes/5 $D &&
+	git update-index --cacheinfo 160000 $D sub1 &&
+
+	git commit -m "updated submodules outside of refs/heads" &&
+	E=$(git rev-parse HEAD) &&
+	git update-ref refs/changes/6 $E &&
+	(
+		cd downstream &&
+		git fetch --recurse-submodules origin refs/changes/6 &&
+		git -C submodule cat-file -t $C &&
+		git -C sub1 cat-file -t $D &&
+		git checkout --recurse-submodules FETCH_HEAD
+	)
+'
+
+test_expect_success 'fetch new submodule commits on-demand without .gitmodules entry' '
+	# depends on the previous test for setup
+
+	git config -f .gitmodules --remove-section submodule.sub1 &&
+	git add .gitmodules &&
+	git commit -m "delete gitmodules file" &&
+	git checkout -B master &&
+	git -C downstream fetch &&
+	git -C downstream checkout origin/master &&
+
+	C=$(git -C submodule commit-tree -m "yet another change outside refs/heads" HEAD^{tree}) &&
+	git -C submodule update-ref refs/changes/7 $C &&
+	git update-index --cacheinfo 160000 $C submodule &&
+	test_tick &&
+
+	D=$(git -C sub1 commit-tree -m "yet another change outside refs/heads" HEAD^{tree}) &&
+	git -C sub1 update-ref refs/changes/8 $D &&
+	git update-index --cacheinfo 160000 $D sub1 &&
+
+	git commit -m "updated submodules outside of refs/heads" &&
+	E=$(git rev-parse HEAD) &&
+	git update-ref refs/changes/9 $E &&
+	(
+		cd downstream &&
+		git fetch --recurse-submodules origin refs/changes/9 &&
+		git -C submodule cat-file -t $C &&
+		git -C sub1 cat-file -t $D &&
+		git checkout --recurse-submodules FETCH_HEAD
+	)
+'
+
+test_expect_success 'fetch new submodule commit intermittently referenced by superproject' '
+	# depends on the previous test for setup
+
+	D=$(git -C sub1 commit-tree -m "change 10 outside refs/heads" HEAD^{tree}) &&
+	E=$(git -C sub1 commit-tree -m "change 11 outside refs/heads" HEAD^{tree}) &&
+	F=$(git -C sub1 commit-tree -m "change 12 outside refs/heads" HEAD^{tree}) &&
+
+	git -C sub1 update-ref refs/changes/10 $D &&
+	git update-index --cacheinfo 160000 $D sub1 &&
+	git commit -m "updated submodules outside of refs/heads" &&
+
+	git -C sub1 update-ref refs/changes/11 $E &&
+	git update-index --cacheinfo 160000 $E sub1 &&
+	git commit -m "updated submodules outside of refs/heads" &&
+
+	git -C sub1 update-ref refs/changes/12 $F &&
+	git update-index --cacheinfo 160000 $F sub1 &&
+	git commit -m "updated submodules outside of refs/heads" &&
+
+	G=$(git rev-parse HEAD) &&
+	git update-ref refs/changes/13 $G &&
+	(
+		cd downstream &&
+		git fetch --recurse-submodules origin refs/changes/13 &&
+
+		git -C sub1 cat-file -t $D &&
+		git -C sub1 cat-file -t $E &&
+		git -C sub1 cat-file -t $F
+	)
+'
+
+test_done