t/t5324-split-commit-graph.sh

   1 #!/bin/sh
   2
   3 test_description='split commit graph'
   4
   5 TEST_PASSES_SANITIZE_LEAK=true
   6 . ./test-lib.sh
   7 . "$TEST_DIRECTORY"/lib-chunk.sh
   8
   9 GIT_TEST_COMMIT_GRAPH=0
  10 GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS=0
  11
  12 test_expect_success 'setup repo' '
  13         git init &&
  14         git config core.commitGraph true &&
  15         git config gc.writeCommitGraph false &&
  16         infodir=".git/objects/info" &&
  17         graphdir="$infodir/commit-graphs" &&
  18         test_oid_cache <<-EOM
  19         shallow sha1:2132
  20         shallow sha256:2436
  21
  22         base sha1:1408
  23         base sha256:1528
  24
  25         oid_version sha1:1
  26         oid_version sha256:2
  27         EOM
  28 '
  29
  30 graph_read_expect() {
  31         NUM_BASE=0
  32         if test ! -z $2
  33         then
  34                 NUM_BASE=$2
  35         fi
  36         OPTIONS=
  37         if test -z "$3"
  38         then
  39                 OPTIONS=" read_generation_data"
  40         fi
  41         cat >expect <<- EOF
  42         header: 43475048 1 $(test_oid oid_version) 4 $NUM_BASE
  43         num_commits: $1
  44         chunks: oid_fanout oid_lookup commit_metadata generation_data
  45         options:$OPTIONS
  46         EOF
  47         test-tool read-graph >output &&
  48         test_cmp expect output
  49 }
  50
  51 test_expect_success POSIXPERM 'tweak umask for modebit tests' '
  52         umask 022
  53 '
  54
  55 test_expect_success 'create commits and write commit-graph' '
  56         for i in $(test_seq 3)
  57         do
  58                 test_commit $i &&
  59                 git branch commits/$i || return 1
  60         done &&
  61         git commit-graph write --reachable &&
  62         test_path_is_file $infodir/commit-graph &&
  63         graph_read_expect 3
  64 '
  65
  66 graph_git_two_modes() {
  67         git ${2:+ -C "$2"} -c core.commitGraph=true $1 >output &&
  68         git ${2:+ -C "$2"} -c core.commitGraph=false $1 >expect &&
  69         test_cmp expect output
  70 }
  71
  72 graph_git_behavior() {
  73         MSG=$1
  74         BRANCH=$2
  75         COMPARE=$3
  76         DIR=$4
  77         test_expect_success "check normal git operations: $MSG" '
  78                 graph_git_two_modes "log --oneline $BRANCH" "$DIR" &&
  79                 graph_git_two_modes "log --topo-order $BRANCH" "$DIR" &&
  80                 graph_git_two_modes "log --graph $COMPARE..$BRANCH" "$DIR" &&
  81                 graph_git_two_modes "branch -vv" "$DIR" &&
  82                 graph_git_two_modes "merge-base -a $BRANCH $COMPARE" "$DIR"
  83         '
  84 }
  85
  86 graph_git_behavior 'graph exists' commits/3 commits/1
  87
  88 verify_chain_files_exist() {
  89         for hash in $(cat $1/commit-graph-chain)
  90         do
  91                 test_path_is_file $1/graph-$hash.graph || return 1
  92         done
  93 }
  94
  95 test_expect_success 'add more commits, and write a new base graph' '
  96         git reset --hard commits/1 &&
  97         for i in $(test_seq 4 5)
  98         do
  99                 test_commit $i &&
 100                 git branch commits/$i || return 1
 101         done &&
 102         git reset --hard commits/2 &&
 103         for i in $(test_seq 6 10)
 104         do
 105                 test_commit $i &&
 106                 git branch commits/$i || return 1
 107         done &&
 108         git reset --hard commits/2 &&
 109         git merge commits/4 &&
 110         git branch merge/1 &&
 111         git reset --hard commits/4 &&
 112         git merge commits/6 &&
 113         git branch merge/2 &&
 114         git commit-graph write --reachable &&
 115         graph_read_expect 12
 116 '
 117
 118 test_expect_success 'fork and fail to base a chain on a commit-graph file' '
 119         test_when_finished rm -rf fork &&
 120         git clone . fork &&
 121         (
 122                 cd fork &&
 123                 rm .git/objects/info/commit-graph &&
 124                 echo "$(pwd)/../.git/objects" >.git/objects/info/alternates &&
 125                 test_commit new-commit &&
 126                 git commit-graph write --reachable --split &&
 127                 test_path_is_file $graphdir/commit-graph-chain &&
 128                 test_line_count = 1 $graphdir/commit-graph-chain &&
 129                 verify_chain_files_exist $graphdir
 130         )
 131 '
 132
 133 test_expect_success 'add three more commits, write a tip graph' '
 134         git reset --hard commits/3 &&
 135         git merge merge/1 &&
 136         git merge commits/5 &&
 137         git merge merge/2 &&
 138         git branch merge/3 &&
 139         git commit-graph write --reachable --split &&
 140         test_path_is_missing $infodir/commit-graph &&
 141         test_path_is_file $graphdir/commit-graph-chain &&
 142         ls $graphdir/graph-*.graph >graph-files &&
 143         test_line_count = 2 graph-files &&
 144         verify_chain_files_exist $graphdir
 145 '
 146
 147 graph_git_behavior 'split commit-graph: merge 3 vs 2' merge/3 merge/2
 148
 149 test_expect_success 'add one commit, write a tip graph' '
 150         test_commit 11 &&
 151         git branch commits/11 &&
 152         git commit-graph write --reachable --split &&
 153         test_path_is_missing $infodir/commit-graph &&
 154         test_path_is_file $graphdir/commit-graph-chain &&
 155         ls $graphdir/graph-*.graph >graph-files &&
 156         test_line_count = 3 graph-files &&
 157         verify_chain_files_exist $graphdir
 158 '
 159
 160 graph_git_behavior 'three-layer commit-graph: commit 11 vs 6' commits/11 commits/6
 161
 162 test_expect_success 'add one commit, write a merged graph' '
 163         test_commit 12 &&
 164         git branch commits/12 &&
 165         git commit-graph write --reachable --split &&
 166         test_path_is_file $graphdir/commit-graph-chain &&
 167         test_line_count = 2 $graphdir/commit-graph-chain &&
 168         ls $graphdir/graph-*.graph >graph-files &&
 169         test_line_count = 2 graph-files &&
 170         verify_chain_files_exist $graphdir
 171 '
 172
 173 graph_git_behavior 'merged commit-graph: commit 12 vs 6' commits/12 commits/6
 174
 175 test_expect_success 'create fork and chain across alternate' '
 176         git clone . fork &&
 177         (
 178                 cd fork &&
 179                 git config core.commitGraph true &&
 180                 rm -rf $graphdir &&
 181                 echo "$(pwd)/../.git/objects" >.git/objects/info/alternates &&
 182                 test_commit 13 &&
 183                 git branch commits/13 &&
 184                 git commit-graph write --reachable --split &&
 185                 test_path_is_file $graphdir/commit-graph-chain &&
 186                 test_line_count = 3 $graphdir/commit-graph-chain &&
 187                 ls $graphdir/graph-*.graph >graph-files &&
 188                 test_line_count = 1 graph-files &&
 189                 git -c core.commitGraph=true  rev-list HEAD >expect &&
 190                 git -c core.commitGraph=false rev-list HEAD >actual &&
 191                 test_cmp expect actual &&
 192                 test_commit 14 &&
 193                 git commit-graph write --reachable --split --object-dir=.git/objects/ &&
 194                 test_line_count = 3 $graphdir/commit-graph-chain &&
 195                 ls $graphdir/graph-*.graph >graph-files &&
 196                 test_line_count = 1 graph-files
 197         )
 198 '
 199
 200 if test -d fork
 201 then
 202         graph_git_behavior 'alternate: commit 13 vs 6' commits/13 origin/commits/6 "fork"
 203 fi
 204
 205 test_expect_success 'test merge stragety constants' '
 206         git clone . merge-2 &&
 207         (
 208                 cd merge-2 &&
 209                 git config core.commitGraph true &&
 210                 test_line_count = 2 $graphdir/commit-graph-chain &&
 211                 test_commit 14 &&
 212                 git commit-graph write --reachable --split --size-multiple=2 &&
 213                 test_line_count = 3 $graphdir/commit-graph-chain
 214
 215         ) &&
 216         git clone . merge-10 &&
 217         (
 218                 cd merge-10 &&
 219                 git config core.commitGraph true &&
 220                 test_line_count = 2 $graphdir/commit-graph-chain &&
 221                 test_commit 14 &&
 222                 git commit-graph write --reachable --split --size-multiple=10 &&
 223                 test_line_count = 1 $graphdir/commit-graph-chain &&
 224                 ls $graphdir/graph-*.graph >graph-files &&
 225                 test_line_count = 1 graph-files
 226         ) &&
 227         git clone . merge-10-expire &&
 228         (
 229                 cd merge-10-expire &&
 230                 git config core.commitGraph true &&
 231                 test_line_count = 2 $graphdir/commit-graph-chain &&
 232                 test_commit 15 &&
 233                 touch $graphdir/to-delete.graph $graphdir/to-keep.graph &&
 234                 test-tool chmtime =1546362000 $graphdir/to-delete.graph &&
 235                 test-tool chmtime =1546362001 $graphdir/to-keep.graph &&
 236                 git commit-graph write --reachable --split --size-multiple=10 \
 237                         --expire-time="2019-01-01 12:00 -05:00" &&
 238                 test_line_count = 1 $graphdir/commit-graph-chain &&
 239                 test_path_is_missing $graphdir/to-delete.graph &&
 240                 test_path_is_file $graphdir/to-keep.graph &&
 241                 ls $graphdir/graph-*.graph >graph-files &&
 242                 test_line_count = 3 graph-files
 243         ) &&
 244         git clone --no-hardlinks . max-commits &&
 245         (
 246                 cd max-commits &&
 247                 git config core.commitGraph true &&
 248                 test_line_count = 2 $graphdir/commit-graph-chain &&
 249                 test_commit 16 &&
 250                 test_commit 17 &&
 251                 git commit-graph write --reachable --split --max-commits=1 &&
 252                 test_line_count = 1 $graphdir/commit-graph-chain &&
 253                 ls $graphdir/graph-*.graph >graph-files &&
 254                 test_line_count = 1 graph-files
 255         )
 256 '
 257
 258 test_expect_success 'remove commit-graph-chain file after flattening' '
 259         git clone . flatten &&
 260         (
 261                 cd flatten &&
 262                 test_line_count = 2 $graphdir/commit-graph-chain &&
 263                 git commit-graph write --reachable &&
 264                 test_path_is_missing $graphdir/commit-graph-chain &&
 265                 ls $graphdir >graph-files &&
 266                 test_line_count = 0 graph-files
 267         )
 268 '
 269
 270 corrupt_file() {
 271         file=$1
 272         pos=$2
 273         data="${3:-\0}"
 274         chmod a+w "$file" &&
 275         printf "$data" | dd of="$file" bs=1 seek="$pos" conv=notrunc
 276 }
 277
 278 test_expect_success 'verify hashes along chain, even in shallow' '
 279         git clone --no-hardlinks . verify &&
 280         (
 281                 cd verify &&
 282                 git commit-graph verify &&
 283                 base_file=$graphdir/graph-$(head -n 1 $graphdir/commit-graph-chain).graph &&
 284                 corrupt_file "$base_file" $(test_oid shallow) "\01" &&
 285                 test_must_fail git commit-graph verify --shallow 2>test_err &&
 286                 grep -v "^+" test_err >err &&
 287                 test_grep "incorrect checksum" err
 288         )
 289 '
 290
 291 test_expect_success 'verify notices chain slice which is bogus (base)' '
 292         git clone --no-hardlinks . verify-chain-bogus-base &&
 293         (
 294                 cd verify-chain-bogus-base &&
 295                 git commit-graph verify &&
 296                 base_file=$graphdir/graph-$(sed -n 1p $graphdir/commit-graph-chain).graph &&
 297                 echo "garbage" >$base_file &&
 298                 test_must_fail git commit-graph verify 2>test_err &&
 299                 grep -v "^+" test_err >err &&
 300                 grep "commit-graph file is too small" err
 301         )
 302 '
 303
 304 test_expect_success 'verify notices chain slice which is bogus (tip)' '
 305         git clone --no-hardlinks . verify-chain-bogus-tip &&
 306         (
 307                 cd verify-chain-bogus-tip &&
 308                 git commit-graph verify &&
 309                 tip_file=$graphdir/graph-$(sed -n 2p $graphdir/commit-graph-chain).graph &&
 310                 echo "garbage" >$tip_file &&
 311                 test_must_fail git commit-graph verify 2>test_err &&
 312                 grep -v "^+" test_err >err &&
 313                 grep "commit-graph file is too small" err
 314         )
 315 '
 316
 317 test_expect_success 'verify --shallow does not check base contents' '
 318         git clone --no-hardlinks . verify-shallow &&
 319         (
 320                 cd verify-shallow &&
 321                 git commit-graph verify &&
 322                 base_file=$graphdir/graph-$(head -n 1 $graphdir/commit-graph-chain).graph &&
 323                 corrupt_file "$base_file" 1500 "\01" &&
 324                 git commit-graph verify --shallow &&
 325                 test_must_fail git commit-graph verify 2>test_err &&
 326                 grep -v "^+" test_err >err &&
 327                 test_grep "incorrect checksum" err
 328         )
 329 '
 330
 331 test_expect_success 'warn on base graph chunk incorrect' '
 332         git clone --no-hardlinks . base-chunk &&
 333         (
 334                 cd base-chunk &&
 335                 git commit-graph verify &&
 336                 base_file=$graphdir/graph-$(tail -n 1 $graphdir/commit-graph-chain).graph &&
 337                 corrupt_file "$base_file" $(test_oid base) "\01" &&
 338                 test_must_fail git commit-graph verify --shallow 2>test_err &&
 339                 grep -v "^+" test_err >err &&
 340                 test_grep "commit-graph chain does not match" err
 341         )
 342 '
 343
 344 test_expect_success 'verify after commit-graph-chain corruption (base)' '
 345         git clone --no-hardlinks . verify-chain-base &&
 346         (
 347                 cd verify-chain-base &&
 348                 corrupt_file "$graphdir/commit-graph-chain" 30 "G" &&
 349                 test_must_fail git commit-graph verify 2>test_err &&
 350                 grep -v "^+" test_err >err &&
 351                 test_grep "invalid commit-graph chain" err &&
 352                 corrupt_file "$graphdir/commit-graph-chain" 30 "A" &&
 353                 test_must_fail git commit-graph verify 2>test_err &&
 354                 grep -v "^+" test_err >err &&
 355                 test_grep "unable to find all commit-graph files" err
 356         )
 357 '
 358
 359 test_expect_success 'verify after commit-graph-chain corruption (tip)' '
 360         git clone --no-hardlinks . verify-chain-tip &&
 361         (
 362                 cd verify-chain-tip &&
 363                 corrupt_file "$graphdir/commit-graph-chain" 70 "G" &&
 364                 test_must_fail git commit-graph verify 2>test_err &&
 365                 grep -v "^+" test_err >err &&
 366                 test_grep "invalid commit-graph chain" err &&
 367                 corrupt_file "$graphdir/commit-graph-chain" 70 "A" &&
 368                 test_must_fail git commit-graph verify 2>test_err &&
 369                 grep -v "^+" test_err >err &&
 370                 test_grep "unable to find all commit-graph files" err
 371         )
 372 '
 373
 374 test_expect_success 'verify notices too-short chain file' '
 375         git clone --no-hardlinks . verify-chain-short &&
 376         (
 377                 cd verify-chain-short &&
 378                 git commit-graph verify &&
 379                 echo "garbage" >$graphdir/commit-graph-chain &&
 380                 test_must_fail git commit-graph verify 2>test_err &&
 381                 grep -v "^+" test_err >err &&
 382                 grep "commit-graph chain file too small" err
 383         )
 384 '
 385
 386 test_expect_success 'verify across alternates' '
 387         git clone --no-hardlinks . verify-alt &&
 388         (
 389                 cd verify-alt &&
 390                 rm -rf $graphdir &&
 391                 altdir="$(pwd)/../.git/objects" &&
 392                 echo "$altdir" >.git/objects/info/alternates &&
 393                 git commit-graph verify --object-dir="$altdir/" &&
 394                 test_commit extra &&
 395                 git commit-graph write --reachable --split &&
 396                 tip_file=$graphdir/graph-$(tail -n 1 $graphdir/commit-graph-chain).graph &&
 397                 corrupt_file "$tip_file" 1500 "\01" &&
 398                 test_must_fail git commit-graph verify --shallow 2>test_err &&
 399                 grep -v "^+" test_err >err &&
 400                 test_grep "incorrect checksum" err
 401         )
 402 '
 403
 404 test_expect_success 'reader bounds-checks base-graph chunk' '
 405         git clone --no-hardlinks . corrupt-base-chunk &&
 406         (
 407                 cd corrupt-base-chunk &&
 408                 tip_file=$graphdir/graph-$(tail -n 1 $graphdir/commit-graph-chain).graph &&
 409                 corrupt_chunk_file "$tip_file" BASE clear 01020304 &&
 410                 git -c core.commitGraph=false log >expect.out &&
 411                 git -c core.commitGraph=true log >out 2>err &&
 412                 test_cmp expect.out out &&
 413                 grep "commit-graph base graphs chunk is too small" err
 414         )
 415 '
 416
 417 test_expect_success 'add octopus merge' '
 418         git reset --hard commits/10 &&
 419         git merge commits/3 commits/4 &&
 420         git branch merge/octopus &&
 421         git commit-graph write --reachable --split &&
 422         git commit-graph verify --progress 2>err &&
 423         test_line_count = 1 err &&
 424         grep "Verifying commits in commit graph: 100% (18/18)" err &&
 425         test_grep ! warning err &&
 426         test_line_count = 3 $graphdir/commit-graph-chain
 427 '
 428
 429 graph_git_behavior 'graph exists' merge/octopus commits/12
 430
 431 test_expect_success 'split across alternate where alternate is not split' '
 432         git commit-graph write --reachable &&
 433         test_path_is_file .git/objects/info/commit-graph &&
 434         cp .git/objects/info/commit-graph . &&
 435         git clone --no-hardlinks . alt-split &&
 436         (
 437                 cd alt-split &&
 438                 rm -f .git/objects/info/commit-graph &&
 439                 echo "$(pwd)"/../.git/objects >.git/objects/info/alternates &&
 440                 test_commit 18 &&
 441                 git commit-graph write --reachable --split &&
 442                 test_line_count = 1 $graphdir/commit-graph-chain
 443         ) &&
 444         test_cmp commit-graph .git/objects/info/commit-graph
 445 '
 446
 447 test_expect_success '--split=no-merge always writes an incremental' '
 448         test_when_finished rm -rf a b &&
 449         rm -rf $graphdir $infodir/commit-graph &&
 450         git reset --hard commits/2 &&
 451         git rev-list HEAD~1 >a &&
 452         git rev-list HEAD >b &&
 453         git commit-graph write --split --stdin-commits <a &&
 454         git commit-graph write --split=no-merge --stdin-commits <b &&
 455         test_line_count = 2 $graphdir/commit-graph-chain
 456 '
 457
 458 test_expect_success '--split=replace replaces the chain' '
 459         rm -rf $graphdir $infodir/commit-graph &&
 460         git reset --hard commits/3 &&
 461         git rev-list -1 HEAD~2 >a &&
 462         git rev-list -1 HEAD~1 >b &&
 463         git rev-list -1 HEAD >c &&
 464         git commit-graph write --split=no-merge --stdin-commits <a &&
 465         git commit-graph write --split=no-merge --stdin-commits <b &&
 466         git commit-graph write --split=no-merge --stdin-commits <c &&
 467         test_line_count = 3 $graphdir/commit-graph-chain &&
 468         git commit-graph write --stdin-commits --split=replace <b &&
 469         test_path_is_missing $infodir/commit-graph &&
 470         test_path_is_file $graphdir/commit-graph-chain &&
 471         ls $graphdir/graph-*.graph >graph-files &&
 472         test_line_count = 1 graph-files &&
 473         verify_chain_files_exist $graphdir &&
 474         graph_read_expect 2
 475 '
 476
 477 test_expect_success ULIMIT_FILE_DESCRIPTORS 'handles file descriptor exhaustion' '
 478         git init ulimit &&
 479         (
 480                 cd ulimit &&
 481                 for i in $(test_seq 64)
 482                 do
 483                         test_commit $i &&
 484                         run_with_limited_open_files test_might_fail git commit-graph write \
 485                                 --split=no-merge --reachable || return 1
 486                 done
 487         )
 488 '
 489
 490 while read mode modebits
 491 do
 492         test_expect_success POSIXPERM "split commit-graph respects core.sharedrepository $mode" '
 493                 rm -rf $graphdir $infodir/commit-graph &&
 494                 git reset --hard commits/1 &&
 495                 test_config core.sharedrepository "$mode" &&
 496                 git commit-graph write --split --reachable &&
 497                 ls $graphdir/graph-*.graph >graph-files &&
 498                 test_line_count = 1 graph-files &&
 499                 echo "$modebits" >expect &&
 500                 test_modebits $graphdir/graph-*.graph >actual &&
 501                 test_cmp expect actual &&
 502                 test_modebits $graphdir/commit-graph-chain >actual &&
 503                 test_cmp expect actual
 504         '
 505 done <<\EOF
 506 0666 -r--r--r--
 507 0600 -r--------
 508 EOF
 509
 510 test_expect_success '--split=replace with partial Bloom data' '
 511         rm -rf $graphdir $infodir/commit-graph &&
 512         git reset --hard commits/3 &&
 513         git rev-list -1 HEAD~2 >a &&
 514         git rev-list -1 HEAD~1 >b &&
 515         git commit-graph write --split=no-merge --stdin-commits --changed-paths <a &&
 516         git commit-graph write --split=no-merge --stdin-commits <b &&
 517         git commit-graph write --split=replace --stdin-commits --changed-paths <c &&
 518         ls $graphdir/graph-*.graph >graph-files &&
 519         test_line_count = 1 graph-files &&
 520         verify_chain_files_exist $graphdir
 521 '
 522
 523 test_expect_success 'prevent regression for duplicate commits across layers' '
 524         git init dup &&
 525         git -C dup commit --allow-empty -m one &&
 526         git -C dup -c core.commitGraph=false commit-graph write --split=no-merge --reachable 2>err &&
 527         test_grep "attempting to write a commit-graph" err &&
 528         git -C dup commit-graph write --split=no-merge --reachable &&
 529         git -C dup commit --allow-empty -m two &&
 530         git -C dup commit-graph write --split=no-merge --reachable &&
 531         git -C dup commit --allow-empty -m three &&
 532         git -C dup commit-graph write --split --reachable &&
 533         git -C dup commit-graph verify
 534 '
 535
 536 NUM_FIRST_LAYER_COMMITS=64
 537 NUM_SECOND_LAYER_COMMITS=16
 538 NUM_THIRD_LAYER_COMMITS=7
 539 NUM_FOURTH_LAYER_COMMITS=8
 540 NUM_FIFTH_LAYER_COMMITS=16
 541 SECOND_LAYER_SEQUENCE_START=$(($NUM_FIRST_LAYER_COMMITS + 1))
 542 SECOND_LAYER_SEQUENCE_END=$(($SECOND_LAYER_SEQUENCE_START + $NUM_SECOND_LAYER_COMMITS - 1))
 543 THIRD_LAYER_SEQUENCE_START=$(($SECOND_LAYER_SEQUENCE_END + 1))
 544 THIRD_LAYER_SEQUENCE_END=$(($THIRD_LAYER_SEQUENCE_START + $NUM_THIRD_LAYER_COMMITS - 1))
 545 FOURTH_LAYER_SEQUENCE_START=$(($THIRD_LAYER_SEQUENCE_END + 1))
 546 FOURTH_LAYER_SEQUENCE_END=$(($FOURTH_LAYER_SEQUENCE_START + $NUM_FOURTH_LAYER_COMMITS - 1))
 547 FIFTH_LAYER_SEQUENCE_START=$(($FOURTH_LAYER_SEQUENCE_END + 1))
 548 FIFTH_LAYER_SEQUENCE_END=$(($FIFTH_LAYER_SEQUENCE_START + $NUM_FIFTH_LAYER_COMMITS - 1))
 549
 550 # Current split graph chain:
 551 #
 552 #     16 commits (No GDAT)
 553 # ------------------------
 554 #     64 commits (GDAT)
 555 #
 556 test_expect_success 'setup repo for mixed generation commit-graph-chain' '
 557         graphdir=".git/objects/info/commit-graphs" &&
 558         test_oid_cache <<-EOF &&
 559         oid_version sha1:1
 560         oid_version sha256:2
 561         EOF
 562         git init mixed &&
 563         (
 564                 cd mixed &&
 565                 git config core.commitGraph true &&
 566                 git config gc.writeCommitGraph false &&
 567                 for i in $(test_seq $NUM_FIRST_LAYER_COMMITS)
 568                 do
 569                         test_commit $i &&
 570                         git branch commits/$i || return 1
 571                 done &&
 572                 git -c commitGraph.generationVersion=2 commit-graph write --reachable --split &&
 573                 graph_read_expect $NUM_FIRST_LAYER_COMMITS &&
 574                 test_line_count = 1 $graphdir/commit-graph-chain &&
 575                 for i in $(test_seq $SECOND_LAYER_SEQUENCE_START $SECOND_LAYER_SEQUENCE_END)
 576                 do
 577                         test_commit $i &&
 578                         git branch commits/$i || return 1
 579                 done &&
 580                 git -c commitGraph.generationVersion=1 commit-graph write --reachable --split=no-merge &&
 581                 test_line_count = 2 $graphdir/commit-graph-chain &&
 582                 test-tool read-graph >output &&
 583                 cat >expect <<-EOF &&
 584                 header: 43475048 1 $(test_oid oid_version) 4 1
 585                 num_commits: $NUM_SECOND_LAYER_COMMITS
 586                 chunks: oid_fanout oid_lookup commit_metadata
 587                 options:
 588                 EOF
 589                 test_cmp expect output &&
 590                 git commit-graph verify &&
 591                 cat $graphdir/commit-graph-chain
 592         )
 593 '
 594
 595 # The new layer will be added without generation data chunk as it was not
 596 # present on the layer underneath it.
 597 #
 598 #      7 commits (No GDAT)
 599 # ------------------------
 600 #     16 commits (No GDAT)
 601 # ------------------------
 602 #     64 commits (GDAT)
 603 #
 604 test_expect_success 'do not write generation data chunk if not present on existing tip' '
 605         git clone mixed mixed-no-gdat &&
 606         (
 607                 cd mixed-no-gdat &&
 608                 for i in $(test_seq $THIRD_LAYER_SEQUENCE_START $THIRD_LAYER_SEQUENCE_END)
 609                 do
 610                         test_commit $i &&
 611                         git branch commits/$i || return 1
 612                 done &&
 613                 git commit-graph write --reachable --split=no-merge &&
 614                 test_line_count = 3 $graphdir/commit-graph-chain &&
 615                 test-tool read-graph >output &&
 616                 cat >expect <<-EOF &&
 617                 header: 43475048 1 $(test_oid oid_version) 4 2
 618                 num_commits: $NUM_THIRD_LAYER_COMMITS
 619                 chunks: oid_fanout oid_lookup commit_metadata
 620                 options:
 621                 EOF
 622                 test_cmp expect output &&
 623                 git commit-graph verify
 624         )
 625 '
 626
 627 # Number of commits in each layer of the split-commit graph before merge:
 628 #
 629 #      8 commits (No GDAT)
 630 # ------------------------
 631 #      7 commits (No GDAT)
 632 # ------------------------
 633 #     16 commits (No GDAT)
 634 # ------------------------
 635 #     64 commits (GDAT)
 636 #
 637 # The top two layers are merged and do not have generation data chunk as layer below them does
 638 # not have generation data chunk.
 639 #
 640 #     15 commits (No GDAT)
 641 # ------------------------
 642 #     16 commits (No GDAT)
 643 # ------------------------
 644 #     64 commits (GDAT)
 645 #
 646 test_expect_success 'do not write generation data chunk if the topmost remaining layer does not have generation data chunk' '
 647         git clone mixed-no-gdat mixed-merge-no-gdat &&
 648         (
 649                 cd mixed-merge-no-gdat &&
 650                 for i in $(test_seq $FOURTH_LAYER_SEQUENCE_START $FOURTH_LAYER_SEQUENCE_END)
 651                 do
 652                         test_commit $i &&
 653                         git branch commits/$i || return 1
 654                 done &&
 655                 git commit-graph write --reachable --split --size-multiple 1 &&
 656                 test_line_count = 3 $graphdir/commit-graph-chain &&
 657                 test-tool read-graph >output &&
 658                 cat >expect <<-EOF &&
 659                 header: 43475048 1 $(test_oid oid_version) 4 2
 660                 num_commits: $(($NUM_THIRD_LAYER_COMMITS + $NUM_FOURTH_LAYER_COMMITS))
 661                 chunks: oid_fanout oid_lookup commit_metadata
 662                 options:
 663                 EOF
 664                 test_cmp expect output &&
 665                 git commit-graph verify
 666         )
 667 '
 668
 669 # Number of commits in each layer of the split-commit graph before merge:
 670 #
 671 #     16 commits (No GDAT)
 672 # ------------------------
 673 #     15 commits (No GDAT)
 674 # ------------------------
 675 #     16 commits (No GDAT)
 676 # ------------------------
 677 #     64 commits (GDAT)
 678 #
 679 # The top three layers are merged and has generation data chunk as the topmost remaining layer
 680 # has generation data chunk.
 681 #
 682 #     47 commits (GDAT)
 683 # ------------------------
 684 #     64 commits (GDAT)
 685 #
 686 test_expect_success 'write generation data chunk if topmost remaining layer has generation data chunk' '
 687         git clone mixed-merge-no-gdat mixed-merge-gdat &&
 688         (
 689                 cd mixed-merge-gdat &&
 690                 for i in $(test_seq $FIFTH_LAYER_SEQUENCE_START $FIFTH_LAYER_SEQUENCE_END)
 691                 do
 692                         test_commit $i &&
 693                         git branch commits/$i || return 1
 694                 done &&
 695                 git commit-graph write --reachable --split --size-multiple 1 &&
 696                 test_line_count = 2 $graphdir/commit-graph-chain &&
 697                 test-tool read-graph >output &&
 698                 cat >expect <<-EOF &&
 699                 header: 43475048 1 $(test_oid oid_version) 5 1
 700                 num_commits: $(($NUM_SECOND_LAYER_COMMITS + $NUM_THIRD_LAYER_COMMITS + $NUM_FOURTH_LAYER_COMMITS + $NUM_FIFTH_LAYER_COMMITS))
 701                 chunks: oid_fanout oid_lookup commit_metadata generation_data
 702                 options: read_generation_data
 703                 EOF
 704                 test_cmp expect output
 705         )
 706 '
 707
 708 test_expect_success 'write generation data chunk when commit-graph chain is replaced' '
 709         git clone mixed mixed-replace &&
 710         (
 711                 cd mixed-replace &&
 712                 git commit-graph write --reachable --split=replace &&
 713                 test_path_is_file $graphdir/commit-graph-chain &&
 714                 test_line_count = 1 $graphdir/commit-graph-chain &&
 715                 verify_chain_files_exist $graphdir &&
 716                 graph_read_expect $(($NUM_FIRST_LAYER_COMMITS + $NUM_SECOND_LAYER_COMMITS)) &&
 717                 git commit-graph verify
 718         )
 719 '
 720
 721 test_done