git-commit-vandalism/t/t5324-split-commit-graph.sh
Abhishek Kumar 1fdc383c5c commit-graph: use generation v2 only if entire chain does
Since there are released versions of Git that understand generation
numbers in the commit-graph's CDAT chunk but do not understand the GDAT
chunk, the following scenario is possible:

1. "New" Git writes a commit-graph with the GDAT chunk.
2. "Old" Git writes a split commit-graph on top without a GDAT chunk.

If each layer of split commit-graph is treated independently, as it was
the case before this commit, with Git inspecting only the current layer
for chunk_generation_data pointer, commits in the lower layer (one with
GDAT) whould have corrected commit date as their generation number,
while commits in the upper layer would have topological levels as their
generation. Corrected commit dates usually have much larger values than
topological levels. This means that if we take two commits, one from the
upper layer, and one reachable from it in the lower layer, then the
expectation that the generation of a parent is smaller than the
generation of a child would be violated.

It is difficult to expose this issue in a test. Since we _start_ with
artificially low generation numbers, any commit walk that prioritizes
generation numbers will walk all of the commits with high generation
number before walking the commits with low generation number. In all the
cases I tried, the commit-graph layers themselves "protect" any
incorrect behavior since none of the commits in the lower layer can
reach the commits in the upper layer.

This issue would manifest itself as a performance problem in this case,
especially with something like "git log --graph" since the low
generation numbers would cause the in-degree queue to walk all of the
commits in the lower layer before allowing the topo-order queue to write
anything to output (depending on the size of the upper layer).

Therefore, When writing the new layer in split commit-graph, we write a
GDAT chunk only if the topmost layer has a GDAT chunk. This guarantees
that if a layer has GDAT chunk, all lower layers must have a GDAT chunk
as well.

Rewriting layers follows similar approach: if the topmost layer below
the set of layers being rewritten (in the split commit-graph chain)
exists, and it does not contain GDAT chunk, then the result of rewrite
does not have GDAT chunks either.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Abhishek Kumar <abhishekkumar8222@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-18 16:21:18 -08:00

638 lines
20 KiB
Bash
Executable File

#!/bin/sh
test_description='split commit graph'
. ./test-lib.sh
GIT_TEST_COMMIT_GRAPH=0
GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS=0
test_expect_success 'setup repo' '
git init &&
git config core.commitGraph true &&
git config gc.writeCommitGraph false &&
infodir=".git/objects/info" &&
graphdir="$infodir/commit-graphs" &&
test_oid_cache <<-EOM
shallow sha1:2132
shallow sha256:2436
base sha1:1408
base sha256:1528
oid_version sha1:1
oid_version sha256:2
EOM
'
graph_read_expect() {
NUM_BASE=0
if test ! -z $2
then
NUM_BASE=$2
fi
cat >expect <<- EOF
header: 43475048 1 $(test_oid oid_version) 4 $NUM_BASE
num_commits: $1
chunks: oid_fanout oid_lookup commit_metadata generation_data
EOF
test-tool read-graph >output &&
test_cmp expect output
}
test_expect_success POSIXPERM 'tweak umask for modebit tests' '
umask 022
'
test_expect_success 'create commits and write commit-graph' '
for i in $(test_seq 3)
do
test_commit $i &&
git branch commits/$i || return 1
done &&
git commit-graph write --reachable &&
test_path_is_file $infodir/commit-graph &&
graph_read_expect 3
'
graph_git_two_modes() {
git -c core.commitGraph=true $1 >output
git -c core.commitGraph=false $1 >expect
test_cmp expect output
}
graph_git_behavior() {
MSG=$1
BRANCH=$2
COMPARE=$3
test_expect_success "check normal git operations: $MSG" '
graph_git_two_modes "log --oneline $BRANCH" &&
graph_git_two_modes "log --topo-order $BRANCH" &&
graph_git_two_modes "log --graph $COMPARE..$BRANCH" &&
graph_git_two_modes "branch -vv" &&
graph_git_two_modes "merge-base -a $BRANCH $COMPARE"
'
}
graph_git_behavior 'graph exists' commits/3 commits/1
verify_chain_files_exist() {
for hash in $(cat $1/commit-graph-chain)
do
test_path_is_file $1/graph-$hash.graph || return 1
done
}
test_expect_success 'add more commits, and write a new base graph' '
git reset --hard commits/1 &&
for i in $(test_seq 4 5)
do
test_commit $i &&
git branch commits/$i || return 1
done &&
git reset --hard commits/2 &&
for i in $(test_seq 6 10)
do
test_commit $i &&
git branch commits/$i || return 1
done &&
git reset --hard commits/2 &&
git merge commits/4 &&
git branch merge/1 &&
git reset --hard commits/4 &&
git merge commits/6 &&
git branch merge/2 &&
git commit-graph write --reachable &&
graph_read_expect 12
'
test_expect_success 'fork and fail to base a chain on a commit-graph file' '
test_when_finished rm -rf fork &&
git clone . fork &&
(
cd fork &&
rm .git/objects/info/commit-graph &&
echo "$(pwd)/../.git/objects" >.git/objects/info/alternates &&
test_commit new-commit &&
git commit-graph write --reachable --split &&
test_path_is_file $graphdir/commit-graph-chain &&
test_line_count = 1 $graphdir/commit-graph-chain &&
verify_chain_files_exist $graphdir
)
'
test_expect_success 'add three more commits, write a tip graph' '
git reset --hard commits/3 &&
git merge merge/1 &&
git merge commits/5 &&
git merge merge/2 &&
git branch merge/3 &&
git commit-graph write --reachable --split &&
test_path_is_missing $infodir/commit-graph &&
test_path_is_file $graphdir/commit-graph-chain &&
ls $graphdir/graph-*.graph >graph-files &&
test_line_count = 2 graph-files &&
verify_chain_files_exist $graphdir
'
graph_git_behavior 'split commit-graph: merge 3 vs 2' merge/3 merge/2
test_expect_success 'add one commit, write a tip graph' '
test_commit 11 &&
git branch commits/11 &&
git commit-graph write --reachable --split &&
test_path_is_missing $infodir/commit-graph &&
test_path_is_file $graphdir/commit-graph-chain &&
ls $graphdir/graph-*.graph >graph-files &&
test_line_count = 3 graph-files &&
verify_chain_files_exist $graphdir
'
graph_git_behavior 'three-layer commit-graph: commit 11 vs 6' commits/11 commits/6
test_expect_success 'add one commit, write a merged graph' '
test_commit 12 &&
git branch commits/12 &&
git commit-graph write --reachable --split &&
test_path_is_file $graphdir/commit-graph-chain &&
test_line_count = 2 $graphdir/commit-graph-chain &&
ls $graphdir/graph-*.graph >graph-files &&
test_line_count = 2 graph-files &&
verify_chain_files_exist $graphdir
'
graph_git_behavior 'merged commit-graph: commit 12 vs 6' commits/12 commits/6
test_expect_success 'create fork and chain across alternate' '
git clone . fork &&
(
cd fork &&
git config core.commitGraph true &&
rm -rf $graphdir &&
echo "$(pwd)/../.git/objects" >.git/objects/info/alternates &&
test_commit 13 &&
git branch commits/13 &&
git commit-graph write --reachable --split &&
test_path_is_file $graphdir/commit-graph-chain &&
test_line_count = 3 $graphdir/commit-graph-chain &&
ls $graphdir/graph-*.graph >graph-files &&
test_line_count = 1 graph-files &&
git -c core.commitGraph=true rev-list HEAD >expect &&
git -c core.commitGraph=false rev-list HEAD >actual &&
test_cmp expect actual &&
test_commit 14 &&
git commit-graph write --reachable --split --object-dir=.git/objects/ &&
test_line_count = 3 $graphdir/commit-graph-chain &&
ls $graphdir/graph-*.graph >graph-files &&
test_line_count = 1 graph-files
)
'
graph_git_behavior 'alternate: commit 13 vs 6' commits/13 commits/6
test_expect_success 'test merge stragety constants' '
git clone . merge-2 &&
(
cd merge-2 &&
git config core.commitGraph true &&
test_line_count = 2 $graphdir/commit-graph-chain &&
test_commit 14 &&
git commit-graph write --reachable --split --size-multiple=2 &&
test_line_count = 3 $graphdir/commit-graph-chain
) &&
git clone . merge-10 &&
(
cd merge-10 &&
git config core.commitGraph true &&
test_line_count = 2 $graphdir/commit-graph-chain &&
test_commit 14 &&
git commit-graph write --reachable --split --size-multiple=10 &&
test_line_count = 1 $graphdir/commit-graph-chain &&
ls $graphdir/graph-*.graph >graph-files &&
test_line_count = 1 graph-files
) &&
git clone . merge-10-expire &&
(
cd merge-10-expire &&
git config core.commitGraph true &&
test_line_count = 2 $graphdir/commit-graph-chain &&
test_commit 15 &&
touch $graphdir/to-delete.graph $graphdir/to-keep.graph &&
test-tool chmtime =1546362000 $graphdir/to-delete.graph &&
test-tool chmtime =1546362001 $graphdir/to-keep.graph &&
git commit-graph write --reachable --split --size-multiple=10 \
--expire-time="2019-01-01 12:00 -05:00" &&
test_line_count = 1 $graphdir/commit-graph-chain &&
test_path_is_missing $graphdir/to-delete.graph &&
test_path_is_file $graphdir/to-keep.graph &&
ls $graphdir/graph-*.graph >graph-files &&
test_line_count = 3 graph-files
) &&
git clone --no-hardlinks . max-commits &&
(
cd max-commits &&
git config core.commitGraph true &&
test_line_count = 2 $graphdir/commit-graph-chain &&
test_commit 16 &&
test_commit 17 &&
git commit-graph write --reachable --split --max-commits=1 &&
test_line_count = 1 $graphdir/commit-graph-chain &&
ls $graphdir/graph-*.graph >graph-files &&
test_line_count = 1 graph-files
)
'
test_expect_success 'remove commit-graph-chain file after flattening' '
git clone . flatten &&
(
cd flatten &&
test_line_count = 2 $graphdir/commit-graph-chain &&
git commit-graph write --reachable &&
test_path_is_missing $graphdir/commit-graph-chain &&
ls $graphdir >graph-files &&
test_line_count = 0 graph-files
)
'
corrupt_file() {
file=$1
pos=$2
data="${3:-\0}"
chmod a+w "$file" &&
printf "$data" | dd of="$file" bs=1 seek="$pos" conv=notrunc
}
test_expect_success 'verify hashes along chain, even in shallow' '
git clone --no-hardlinks . verify &&
(
cd verify &&
git commit-graph verify &&
base_file=$graphdir/graph-$(head -n 1 $graphdir/commit-graph-chain).graph &&
corrupt_file "$base_file" $(test_oid shallow) "\01" &&
test_must_fail git commit-graph verify --shallow 2>test_err &&
grep -v "^+" test_err >err &&
test_i18ngrep "incorrect checksum" err
)
'
test_expect_success 'verify --shallow does not check base contents' '
git clone --no-hardlinks . verify-shallow &&
(
cd verify-shallow &&
git commit-graph verify &&
base_file=$graphdir/graph-$(head -n 1 $graphdir/commit-graph-chain).graph &&
corrupt_file "$base_file" 1000 "\01" &&
git commit-graph verify --shallow &&
test_must_fail git commit-graph verify 2>test_err &&
grep -v "^+" test_err >err &&
test_i18ngrep "incorrect checksum" err
)
'
test_expect_success 'warn on base graph chunk incorrect' '
git clone --no-hardlinks . base-chunk &&
(
cd base-chunk &&
git commit-graph verify &&
base_file=$graphdir/graph-$(tail -n 1 $graphdir/commit-graph-chain).graph &&
corrupt_file "$base_file" $(test_oid base) "\01" &&
git commit-graph verify --shallow 2>test_err &&
grep -v "^+" test_err >err &&
test_i18ngrep "commit-graph chain does not match" err
)
'
test_expect_success 'verify after commit-graph-chain corruption' '
git clone --no-hardlinks . verify-chain &&
(
cd verify-chain &&
corrupt_file "$graphdir/commit-graph-chain" 60 "G" &&
git commit-graph verify 2>test_err &&
grep -v "^+" test_err >err &&
test_i18ngrep "invalid commit-graph chain" err &&
corrupt_file "$graphdir/commit-graph-chain" 60 "A" &&
git commit-graph verify 2>test_err &&
grep -v "^+" test_err >err &&
test_i18ngrep "unable to find all commit-graph files" err
)
'
test_expect_success 'verify across alternates' '
git clone --no-hardlinks . verify-alt &&
(
cd verify-alt &&
rm -rf $graphdir &&
altdir="$(pwd)/../.git/objects" &&
echo "$altdir" >.git/objects/info/alternates &&
git commit-graph verify --object-dir="$altdir/" &&
test_commit extra &&
git commit-graph write --reachable --split &&
tip_file=$graphdir/graph-$(tail -n 1 $graphdir/commit-graph-chain).graph &&
corrupt_file "$tip_file" 100 "\01" &&
test_must_fail git commit-graph verify --shallow 2>test_err &&
grep -v "^+" test_err >err &&
test_i18ngrep "commit-graph has incorrect fanout value" err
)
'
test_expect_success 'add octopus merge' '
git reset --hard commits/10 &&
git merge commits/3 commits/4 &&
git branch merge/octopus &&
git commit-graph write --reachable --split &&
git commit-graph verify --progress 2>err &&
test_line_count = 3 err &&
test_i18ngrep ! warning err &&
test_line_count = 3 $graphdir/commit-graph-chain
'
graph_git_behavior 'graph exists' merge/octopus commits/12
test_expect_success 'split across alternate where alternate is not split' '
git commit-graph write --reachable &&
test_path_is_file .git/objects/info/commit-graph &&
cp .git/objects/info/commit-graph . &&
git clone --no-hardlinks . alt-split &&
(
cd alt-split &&
rm -f .git/objects/info/commit-graph &&
echo "$(pwd)"/../.git/objects >.git/objects/info/alternates &&
test_commit 18 &&
git commit-graph write --reachable --split &&
test_line_count = 1 $graphdir/commit-graph-chain
) &&
test_cmp commit-graph .git/objects/info/commit-graph
'
test_expect_success '--split=no-merge always writes an incremental' '
test_when_finished rm -rf a b &&
rm -rf $graphdir $infodir/commit-graph &&
git reset --hard commits/2 &&
git rev-list HEAD~1 >a &&
git rev-list HEAD >b &&
git commit-graph write --split --stdin-commits <a &&
git commit-graph write --split=no-merge --stdin-commits <b &&
test_line_count = 2 $graphdir/commit-graph-chain
'
test_expect_success '--split=replace replaces the chain' '
rm -rf $graphdir $infodir/commit-graph &&
git reset --hard commits/3 &&
git rev-list -1 HEAD~2 >a &&
git rev-list -1 HEAD~1 >b &&
git rev-list -1 HEAD >c &&
git commit-graph write --split=no-merge --stdin-commits <a &&
git commit-graph write --split=no-merge --stdin-commits <b &&
git commit-graph write --split=no-merge --stdin-commits <c &&
test_line_count = 3 $graphdir/commit-graph-chain &&
git commit-graph write --stdin-commits --split=replace <b &&
test_path_is_missing $infodir/commit-graph &&
test_path_is_file $graphdir/commit-graph-chain &&
ls $graphdir/graph-*.graph >graph-files &&
test_line_count = 1 graph-files &&
verify_chain_files_exist $graphdir &&
graph_read_expect 2
'
test_expect_success ULIMIT_FILE_DESCRIPTORS 'handles file descriptor exhaustion' '
git init ulimit &&
(
cd ulimit &&
for i in $(test_seq 64)
do
test_commit $i &&
run_with_limited_open_files test_might_fail git commit-graph write \
--split=no-merge --reachable || return 1
done
)
'
while read mode modebits
do
test_expect_success POSIXPERM "split commit-graph respects core.sharedrepository $mode" '
rm -rf $graphdir $infodir/commit-graph &&
git reset --hard commits/1 &&
test_config core.sharedrepository "$mode" &&
git commit-graph write --split --reachable &&
ls $graphdir/graph-*.graph >graph-files &&
test_line_count = 1 graph-files &&
echo "$modebits" >expect &&
test_modebits $graphdir/graph-*.graph >actual &&
test_cmp expect actual &&
test_modebits $graphdir/commit-graph-chain >actual &&
test_cmp expect actual
'
done <<\EOF
0666 -r--r--r--
0600 -r--------
EOF
test_expect_success '--split=replace with partial Bloom data' '
rm -rf $graphdir $infodir/commit-graph &&
git reset --hard commits/3 &&
git rev-list -1 HEAD~2 >a &&
git rev-list -1 HEAD~1 >b &&
git commit-graph write --split=no-merge --stdin-commits --changed-paths <a &&
git commit-graph write --split=no-merge --stdin-commits <b &&
git commit-graph write --split=replace --stdin-commits --changed-paths <c &&
ls $graphdir/graph-*.graph >graph-files &&
test_line_count = 1 graph-files &&
verify_chain_files_exist $graphdir
'
test_expect_success 'prevent regression for duplicate commits across layers' '
git init dup &&
git -C dup commit --allow-empty -m one &&
git -C dup -c core.commitGraph=false commit-graph write --split=no-merge --reachable 2>err &&
test_i18ngrep "attempting to write a commit-graph" err &&
git -C dup commit-graph write --split=no-merge --reachable &&
git -C dup commit --allow-empty -m two &&
git -C dup commit-graph write --split=no-merge --reachable &&
git -C dup commit --allow-empty -m three &&
git -C dup commit-graph write --split --reachable &&
git -C dup commit-graph verify
'
NUM_FIRST_LAYER_COMMITS=64
NUM_SECOND_LAYER_COMMITS=16
NUM_THIRD_LAYER_COMMITS=7
NUM_FOURTH_LAYER_COMMITS=8
NUM_FIFTH_LAYER_COMMITS=16
SECOND_LAYER_SEQUENCE_START=$(($NUM_FIRST_LAYER_COMMITS + 1))
SECOND_LAYER_SEQUENCE_END=$(($SECOND_LAYER_SEQUENCE_START + $NUM_SECOND_LAYER_COMMITS - 1))
THIRD_LAYER_SEQUENCE_START=$(($SECOND_LAYER_SEQUENCE_END + 1))
THIRD_LAYER_SEQUENCE_END=$(($THIRD_LAYER_SEQUENCE_START + $NUM_THIRD_LAYER_COMMITS - 1))
FOURTH_LAYER_SEQUENCE_START=$(($THIRD_LAYER_SEQUENCE_END + 1))
FOURTH_LAYER_SEQUENCE_END=$(($FOURTH_LAYER_SEQUENCE_START + $NUM_FOURTH_LAYER_COMMITS - 1))
FIFTH_LAYER_SEQUENCE_START=$(($FOURTH_LAYER_SEQUENCE_END + 1))
FIFTH_LAYER_SEQUENCE_END=$(($FIFTH_LAYER_SEQUENCE_START + $NUM_FIFTH_LAYER_COMMITS - 1))
# Current split graph chain:
#
# 16 commits (No GDAT)
# ------------------------
# 64 commits (GDAT)
#
test_expect_success 'setup repo for mixed generation commit-graph-chain' '
graphdir=".git/objects/info/commit-graphs" &&
test_oid_cache <<-EOF &&
oid_version sha1:1
oid_version sha256:2
EOF
git init mixed &&
(
cd mixed &&
git config core.commitGraph true &&
git config gc.writeCommitGraph false &&
for i in $(test_seq $NUM_FIRST_LAYER_COMMITS)
do
test_commit $i &&
git branch commits/$i || return 1
done &&
git commit-graph write --reachable --split &&
graph_read_expect $NUM_FIRST_LAYER_COMMITS &&
test_line_count = 1 $graphdir/commit-graph-chain &&
for i in $(test_seq $SECOND_LAYER_SEQUENCE_START $SECOND_LAYER_SEQUENCE_END)
do
test_commit $i &&
git branch commits/$i || return 1
done &&
GIT_TEST_COMMIT_GRAPH_NO_GDAT=1 git commit-graph write --reachable --split=no-merge &&
test_line_count = 2 $graphdir/commit-graph-chain &&
test-tool read-graph >output &&
cat >expect <<-EOF &&
header: 43475048 1 $(test_oid oid_version) 4 1
num_commits: $NUM_SECOND_LAYER_COMMITS
chunks: oid_fanout oid_lookup commit_metadata
EOF
test_cmp expect output &&
git commit-graph verify &&
cat $graphdir/commit-graph-chain
)
'
# The new layer will be added without generation data chunk as it was not
# present on the layer underneath it.
#
# 7 commits (No GDAT)
# ------------------------
# 16 commits (No GDAT)
# ------------------------
# 64 commits (GDAT)
#
test_expect_success 'do not write generation data chunk if not present on existing tip' '
git clone mixed mixed-no-gdat &&
(
cd mixed-no-gdat &&
for i in $(test_seq $THIRD_LAYER_SEQUENCE_START $THIRD_LAYER_SEQUENCE_END)
do
test_commit $i &&
git branch commits/$i || return 1
done &&
git commit-graph write --reachable --split=no-merge &&
test_line_count = 3 $graphdir/commit-graph-chain &&
test-tool read-graph >output &&
cat >expect <<-EOF &&
header: 43475048 1 $(test_oid oid_version) 4 2
num_commits: $NUM_THIRD_LAYER_COMMITS
chunks: oid_fanout oid_lookup commit_metadata
EOF
test_cmp expect output &&
git commit-graph verify
)
'
# Number of commits in each layer of the split-commit graph before merge:
#
# 8 commits (No GDAT)
# ------------------------
# 7 commits (No GDAT)
# ------------------------
# 16 commits (No GDAT)
# ------------------------
# 64 commits (GDAT)
#
# The top two layers are merged and do not have generation data chunk as layer below them does
# not have generation data chunk.
#
# 15 commits (No GDAT)
# ------------------------
# 16 commits (No GDAT)
# ------------------------
# 64 commits (GDAT)
#
test_expect_success 'do not write generation data chunk if the topmost remaining layer does not have generation data chunk' '
git clone mixed-no-gdat mixed-merge-no-gdat &&
(
cd mixed-merge-no-gdat &&
for i in $(test_seq $FOURTH_LAYER_SEQUENCE_START $FOURTH_LAYER_SEQUENCE_END)
do
test_commit $i &&
git branch commits/$i || return 1
done &&
git commit-graph write --reachable --split --size-multiple 1 &&
test_line_count = 3 $graphdir/commit-graph-chain &&
test-tool read-graph >output &&
cat >expect <<-EOF &&
header: 43475048 1 $(test_oid oid_version) 4 2
num_commits: $(($NUM_THIRD_LAYER_COMMITS + $NUM_FOURTH_LAYER_COMMITS))
chunks: oid_fanout oid_lookup commit_metadata
EOF
test_cmp expect output &&
git commit-graph verify
)
'
# Number of commits in each layer of the split-commit graph before merge:
#
# 16 commits (No GDAT)
# ------------------------
# 15 commits (No GDAT)
# ------------------------
# 16 commits (No GDAT)
# ------------------------
# 64 commits (GDAT)
#
# The top three layers are merged and has generation data chunk as the topmost remaining layer
# has generation data chunk.
#
# 47 commits (GDAT)
# ------------------------
# 64 commits (GDAT)
#
test_expect_success 'write generation data chunk if topmost remaining layer has generation data chunk' '
git clone mixed-merge-no-gdat mixed-merge-gdat &&
(
cd mixed-merge-gdat &&
for i in $(test_seq $FIFTH_LAYER_SEQUENCE_START $FIFTH_LAYER_SEQUENCE_END)
do
test_commit $i &&
git branch commits/$i || return 1
done &&
git commit-graph write --reachable --split --size-multiple 1 &&
test_line_count = 2 $graphdir/commit-graph-chain &&
test-tool read-graph >output &&
cat >expect <<-EOF &&
header: 43475048 1 $(test_oid oid_version) 5 1
num_commits: $(($NUM_SECOND_LAYER_COMMITS + $NUM_THIRD_LAYER_COMMITS + $NUM_FOURTH_LAYER_COMMITS + $NUM_FIFTH_LAYER_COMMITS))
chunks: oid_fanout oid_lookup commit_metadata generation_data
EOF
test_cmp expect output
)
'
test_expect_success 'write generation data chunk when commit-graph chain is replaced' '
git clone mixed mixed-replace &&
(
cd mixed-replace &&
git commit-graph write --reachable --split=replace &&
test_path_is_file $graphdir/commit-graph-chain &&
test_line_count = 1 $graphdir/commit-graph-chain &&
verify_chain_files_exist $graphdir &&
graph_read_expect $(($NUM_FIRST_LAYER_COMMITS + $NUM_SECOND_LAYER_COMMITS)) &&
git commit-graph verify
)
'
test_done