Re: [PATCH v6 13/16] commit-graph: new Bloom filter version that fixes murmur3

> diff --git a/t/t4216-log-bloom.sh b/t/t4216-log-bloom.sh
> index 93b8d096cf..a7bf3a7dca 100755
> --- a/t/t4216-log-bloom.sh
> +++ b/t/t4216-log-bloom.sh
> @@ -485,6 +485,33 @@ test_expect_success 'merge graph layers with incompatible Bloom settings' '
>  	test_must_be_empty err
>  '
>  
> +test_expect_success 'ensure Bloom filter with incompatible versions are ignored' '
> +	rm "$repo/$graph" &&
> +
> +	git -C $repo log --oneline --no-decorate -- $CENT >expect &&

> +
> +	# Compute v1 Bloom filters for commits at the bottom.
> +	git -C $repo rev-parse HEAD^ >in &&
> +	git -C $repo commit-graph write --stdin-commits --changed-paths \
> +		--split <in &&
> +
> +	# Compute v2 Bloomfilters for the rest of the commits at the top.
> +	git -C $repo rev-parse HEAD >in &&
> +	git -C $repo -c commitGraph.changedPathsVersion=2 commit-graph write \
> +		--stdin-commits --changed-paths --split=no-merge <in &&
> +
> +	test_line_count = 2 $repo/$chain &&
> +
> +	git -C $repo log --oneline --no-decorate -- $CENT >actual 2>err &&
> +	test_cmp expect actual &&
> +
> +	layer="$(head -n 1 $repo/$chain)" &&
> +	cat >expect.err <<-EOF &&
> +	warning: disabling Bloom filters for commit-graph layer $SQ$layer$SQ due to incompatible settings
> +	EOF
> +	test_cmp expect.err err

> +'
> +
>  get_first_changed_path_filter () {
>  	test-tool read-graph bloom-filters >filters.dat &&
>  	head -n 1 filters.dat
> @@ -536,6 +563,120 @@ test_expect_success 'version 1 changed-path used when version 1 requested' '
>  	)
>  '
>  
> +test_expect_success 'version 1 changed-path not used when version 2 requested' '
> +	(
> +		cd highbit1 &&
> +		git config --add commitgraph.changedPathsVersion 2 &&
> +		test_bloom_filters_not_used "-- another$CENT"
> +	)
> +'
> +
> +test_expect_success 'version 1 changed-path used when autodetect requested' '
> +	(
> +		cd highbit1 &&
> +		git config --add commitgraph.changedPathsVersion -1 &&
> +		test_bloom_filters_used "-- another$CENT"
> +	)
> +'
> +
> +test_expect_success 'when writing another commit graph, preserve existing version 1 of changed-path' '
> +	test_commit -C highbit1 c1double "$CENT$CENT" &&
> +	git -C highbit1 commit-graph write --reachable --changed-paths &&
> +	(
> +		cd highbit1 &&
> +		git config --add commitgraph.changedPathsVersion -1 &&
> +		echo "options: bloom(1,10,7) read_generation_data" >expect &&
> +		test-tool read-graph >full &&
> +		grep options full >actual &&
> +		test_cmp expect actual
> +	)
> +'
> +
> +test_expect_success 'set up repo with high bit path, version 2 changed-path' '
> +	git init highbit2 &&
> +	git -C highbit2 config --add commitgraph.changedPathsVersion 2 &&
> +	test_commit -C highbit2 c2 "$CENT" &&
> +	git -C highbit2 commit-graph write --reachable --changed-paths
> +'
> +
> +test_expect_success 'check value of version 2 changed-path' '
> +	(
> +		cd highbit2 &&
> +		echo "c01f" >expect &&
> +		get_first_changed_path_filter >actual &&
> +		test_cmp expect actual
> +	)
> +'
> +
> +test_expect_success 'setup make another commit' '
> +	# "git log" does not use Bloom filters for root commits - see how, in
> +	# revision.c, rev_compare_tree() (the only code path that eventually calls
> +	# get_bloom_filter()) is only called by try_to_simplify_commit() when the commit
> +	# has one parent. Therefore, make another commit so that we perform the tests on
> +	# a non-root commit.
> +	test_commit -C highbit2 anotherc2 "another$CENT"
> +'
> +
> +test_expect_success 'version 2 changed-path used when version 2 requested' '
> +	(
> +		cd highbit2 &&
> +		test_bloom_filters_used "-- another$CENT"
> +	)
> +'
> +
> +test_expect_success 'version 2 changed-path not used when version 1 requested' '
> +	(
> +		cd highbit2 &&
> +		git config --add commitgraph.changedPathsVersion 1 &&
> +		test_bloom_filters_not_used "-- another$CENT"
> +	)
> +'
> +
> +test_expect_success 'version 2 changed-path used when autodetect requested' '
> +	(
> +		cd highbit2 &&
> +		git config --add commitgraph.changedPathsVersion -1 &&
> +		test_bloom_filters_used "-- another$CENT"
> +	)
> +'
> +
> +test_expect_success 'when writing another commit graph, preserve existing version 2 of changed-path' '
> +	test_commit -C highbit2 c2double "$CENT$CENT" &&
> +	git -C highbit2 commit-graph write --reachable --changed-paths &&
> +	(
> +		cd highbit2 &&
> +		git config --add commitgraph.changedPathsVersion -1 &&
> +		echo "options: bloom(2,10,7) read_generation_data" >expect &&
> +		test-tool read-graph >full &&
> +		grep options full >actual &&
> +		test_cmp expect actual
> +	)
> +'
> +
> +test_expect_success 'when writing commit graph, do not reuse changed-path of another version' '
> +	git init doublewrite &&
> +	test_commit -C doublewrite c "$CENT" &&
> +	git -C doublewrite config --add commitgraph.changedPathsVersion 1 &&
> +	git -C doublewrite commit-graph write --reachable --changed-paths &&
> +	for v in -2 3
> +	do
> +		git -C doublewrite config --add commitgraph.changedPathsVersion $v &&
> +		git -C doublewrite commit-graph write --reachable --changed-paths 2>err &&
> +		cat >expect <<-EOF &&
> +		warning: attempting to write a commit-graph, but ${SQ}commitgraph.changedPathsVersion${SQ} ($v) is not supported
> +		EOF
> +		test_cmp expect err || return 1
> +	done &&
> +	git -C doublewrite config --add commitgraph.changedPathsVersion 2 &&
> +	git -C doublewrite commit-graph write --reachable --changed-paths &&

> +	(
> +		cd doublewrite &&
> +		echo "c01f" >expect &&
> +		get_first_changed_path_filter >actual &&
> +		test_cmp expect actual
> +	)
> +'
> +
>  corrupt_graph () {
>  	test_when_finished "rm -rf $graph" &&
>  	git commit-graph write --reachable --changed-paths &&
> -- 
> 2.43.0.509.g253f65a7fc
>