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 . "$TEST_DIRECTORY"/lib-chunk.sh
   8
   9 GIT_TEST_COMMIT_GRAPH=0
  10 GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS=0
  11
  12 test_expect_success 'setup repo' '
  13         git init &&
  14         git config core.commitGraph true &&
  15         git config gc.writeCommitGraph false &&
  16         objdir=".git/objects" &&
  17         infodir="$objdir/info" &&
  18         graphdir="$infodir/commit-graphs" &&
  19         test_oid_cache <<-EOM
  20         shallow sha1:2132
  21         shallow sha256:2436
  22
  23         base sha1:1408
  24         base sha256:1528
  25
  26         oid_version sha1:1
  27         oid_version sha256:2
  28         EOM
  29 '
  30
  31 graph_read_expect() {
  32         NUM_BASE=0
  33         if test ! -z $2
  34         then
  35                 NUM_BASE=$2
  36         fi
  37         OPTIONS=
  38         if test -z "$3"
  39         then
  40                 OPTIONS=" read_generation_data"
  41         fi
  42         cat >expect <<- EOF
  43         header: 43475048 1 $(test_oid oid_version) 4 $NUM_BASE
  44         num_commits: $1
  45         chunks: oid_fanout oid_lookup commit_metadata generation_data
  46         options:$OPTIONS
  47         EOF
  48         test-tool read-graph >output &&
  49         test_cmp expect output
  50 }
  51
  52 test_expect_success POSIXPERM 'tweak umask for modebit tests' '
  53         umask 022
  54 '
  55
  56 test_expect_success 'create commits and write commit-graph' '
  57         for i in $(test_seq 3)
  58         do
  59                 test_commit $i &&
  60                 git branch commits/$i || return 1
  61         done &&
  62         git commit-graph write --reachable &&
  63         test_path_is_file $infodir/commit-graph &&
  64         graph_read_expect 3
  65 '
  66
  67 graph_git_two_modes() {
  68         git ${2:+ -C "$2"} -c core.commitGraph=true $1 >output &&
  69         git ${2:+ -C "$2"} -c core.commitGraph=false $1 >expect &&
  70         test_cmp expect output
  71 }
  72
  73 graph_git_behavior() {
  74         MSG=$1
  75         BRANCH=$2
  76         COMPARE=$3
  77         DIR=$4
  78         test_expect_success "check normal git operations: $MSG" '
  79                 graph_git_two_modes "log --oneline $BRANCH" "$DIR" &&
  80                 graph_git_two_modes "log --topo-order $BRANCH" "$DIR" &&
  81                 graph_git_two_modes "log --graph $COMPARE..$BRANCH" "$DIR" &&
  82                 graph_git_two_modes "branch -vv" "$DIR" &&
  83                 graph_git_two_modes "merge-base -a $BRANCH $COMPARE" "$DIR"
  84         '
  85 }
  86
  87 graph_git_behavior 'graph exists' commits/3 commits/1
  88
  89 verify_chain_files_exist() {
  90         for hash in $(cat $1/commit-graph-chain)
  91         do
  92                 test_path_is_file $1/graph-$hash.graph || return 1
  93         done
  94 }
  95
  96 test_expect_success 'add more commits, and write a new base graph' '
  97         git reset --hard commits/1 &&
  98         for i in $(test_seq 4 5)
  99         do
 100                 test_commit $i &&
 101                 git branch commits/$i || return 1
 102         done &&
 103         git reset --hard commits/2 &&
 104         for i in $(test_seq 6 10)
 105         do
 106                 test_commit $i &&
 107                 git branch commits/$i || return 1
 108         done &&
 109         git reset --hard commits/2 &&
 110         git merge commits/4 &&
 111         git branch merge/1 &&
 112         git reset --hard commits/4 &&
 113         git merge commits/6 &&
 114         git branch merge/2 &&
 115         git commit-graph write --reachable &&
 116         graph_read_expect 12
 117 '
 118
 119 test_expect_success 'fork and fail to base a chain on a commit-graph file' '
 120         test_when_finished rm -rf fork &&
 121         git clone . fork &&
 122         (
 123                 cd fork &&
 124                 rm .git/objects/info/commit-graph &&
 125                 echo "$(pwd)/../.git/objects" >.git/objects/info/alternates &&
 126                 test_commit new-commit &&
 127                 git commit-graph write --reachable --split &&
 128                 test_path_is_file $graphdir/commit-graph-chain &&
 129                 test_line_count = 1 $graphdir/commit-graph-chain &&
 130                 verify_chain_files_exist $graphdir
 131         )
 132 '
 133
 134 test_expect_success 'add three more commits, write a tip graph' '
 135         git reset --hard commits/3 &&
 136         git merge merge/1 &&
 137         git merge commits/5 &&
 138         git merge merge/2 &&
 139         git branch merge/3 &&
 140         git commit-graph write --reachable --split &&
 141         test_path_is_missing $infodir/commit-graph &&
 142         test_path_is_file $graphdir/commit-graph-chain &&
 143         ls $graphdir/graph-*.graph >graph-files &&
 144         test_line_count = 2 graph-files &&
 145         verify_chain_files_exist $graphdir
 146 '
 147
 148 graph_git_behavior 'split commit-graph: merge 3 vs 2' merge/3 merge/2
 149
 150 test_expect_success 'add one commit, write a tip graph' '
 151         test_commit 11 &&
 152         git branch commits/11 &&
 153         git commit-graph write --reachable --split &&
 154         test_path_is_missing $infodir/commit-graph &&
 155         test_path_is_file $graphdir/commit-graph-chain &&
 156         ls $graphdir/graph-*.graph >graph-files &&
 157         test_line_count = 3 graph-files &&
 158         verify_chain_files_exist $graphdir
 159 '
 160
 161 graph_git_behavior 'three-layer commit-graph: commit 11 vs 6' commits/11 commits/6
 162
 163 test_expect_success 'add one commit, write a merged graph' '
 164         test_commit 12 &&
 165         git branch commits/12 &&
 166         git commit-graph write --reachable --split &&
 167         test_path_is_file $graphdir/commit-graph-chain &&
 168         test_line_count = 2 $graphdir/commit-graph-chain &&
 169         ls $graphdir/graph-*.graph >graph-files &&
 170         test_line_count = 2 graph-files &&
 171         verify_chain_files_exist $graphdir
 172 '
 173
 174 graph_git_behavior 'merged commit-graph: commit 12 vs 6' commits/12 commits/6
 175
 176 test_expect_success 'create fork and chain across alternate' '
 177         git clone . fork &&
 178         (
 179                 cd fork &&
 180                 git config core.commitGraph true &&
 181                 rm -rf $graphdir &&
 182                 echo "$(pwd)/../.git/objects" >.git/objects/info/alternates &&
 183                 test_commit 13 &&
 184                 git branch commits/13 &&
 185                 git commit-graph write --reachable --split &&
 186                 test_path_is_file $graphdir/commit-graph-chain &&
 187                 test_line_count = 3 $graphdir/commit-graph-chain &&
 188                 ls $graphdir/graph-*.graph >graph-files &&
 189                 test_line_count = 1 graph-files &&
 190                 git -c core.commitGraph=true  rev-list HEAD >expect &&
 191                 git -c core.commitGraph=false rev-list HEAD >actual &&
 192                 test_cmp expect actual &&
 193                 test_commit 14 &&
 194                 git commit-graph write --reachable --split --object-dir=.git/objects/ &&
 195                 test_line_count = 3 $graphdir/commit-graph-chain &&
 196                 ls $graphdir/graph-*.graph >graph-files &&
 197                 test_line_count = 1 graph-files
 198         )
 199 '
 200
 201 if test -d fork
 202 then
 203         graph_git_behavior 'alternate: commit 13 vs 6' commits/13 origin/commits/6 "fork"
 204 fi
 205
 206 test_expect_success 'test merge stragety constants' '
 207         git clone . merge-2 &&
 208         (
 209                 cd merge-2 &&
 210                 git config core.commitGraph true &&
 211                 test_line_count = 2 $graphdir/commit-graph-chain &&
 212                 test_commit 14 &&
 213                 git commit-graph write --reachable --split --size-multiple=2 &&
 214                 test_line_count = 3 $graphdir/commit-graph-chain
 215
 216         ) &&
 217         git clone . merge-10 &&
 218         (
 219                 cd merge-10 &&
 220                 git config core.commitGraph true &&
 221                 test_line_count = 2 $graphdir/commit-graph-chain &&
 222                 test_commit 14 &&
 223                 git commit-graph write --reachable --split --size-multiple=10 &&
 224                 test_line_count = 1 $graphdir/commit-graph-chain &&
 225                 ls $graphdir/graph-*.graph >graph-files &&
 226                 test_line_count = 1 graph-files
 227         ) &&
 228         git clone . merge-10-expire &&
 229         (
 230                 cd merge-10-expire &&
 231                 git config core.commitGraph true &&
 232                 test_line_count = 2 $graphdir/commit-graph-chain &&
 233                 test_commit 15 &&
 234                 touch $graphdir/to-delete.graph $graphdir/to-keep.graph &&
 235                 test-tool chmtime =1546362000 $graphdir/to-delete.graph &&
 236                 test-tool chmtime =1546362001 $graphdir/to-keep.graph &&
 237                 git commit-graph write --reachable --split --size-multiple=10 \
 238                         --expire-time="2019-01-01 12:00 -05:00" &&
 239                 test_line_count = 1 $graphdir/commit-graph-chain &&
 240                 test_path_is_missing $graphdir/to-delete.graph &&
 241                 test_path_is_file $graphdir/to-keep.graph &&
 242                 ls $graphdir/graph-*.graph >graph-files &&
 243                 test_line_count = 3 graph-files
 244         ) &&
 245         git clone --no-hardlinks . max-commits &&
 246         (
 247                 cd max-commits &&
 248                 git config core.commitGraph true &&
 249                 test_line_count = 2 $graphdir/commit-graph-chain &&
 250                 test_commit 16 &&
 251                 test_commit 17 &&
 252                 git commit-graph write --reachable --split --max-commits=1 &&
 253                 test_line_count = 1 $graphdir/commit-graph-chain &&
 254                 ls $graphdir/graph-*.graph >graph-files &&
 255                 test_line_count = 1 graph-files
 256         )
 257 '
 258
 259 test_expect_success 'remove commit-graph-chain file after flattening' '
 260         git clone . flatten &&
 261         (
 262                 cd flatten &&
 263                 test_line_count = 2 $graphdir/commit-graph-chain &&
 264                 git commit-graph write --reachable &&
 265                 test_path_is_missing $graphdir/commit-graph-chain &&
 266                 ls $graphdir >graph-files &&
 267                 test_line_count = 0 graph-files
 268         )
 269 '
 270
 271 corrupt_file() {
 272         file=$1
 273         pos=$2
 274         data="${3:-\0}"
 275         chmod a+w "$file" &&
 276         printf "$data" | dd of="$file" bs=1 seek="$pos" conv=notrunc
 277 }
 278
 279 test_expect_success 'verify hashes along chain, even in shallow' '
 280         git clone --no-hardlinks . verify &&
 281         (
 282                 cd verify &&
 283                 git commit-graph verify &&
 284                 base_file=$graphdir/graph-$(head -n 1 $graphdir/commit-graph-chain).graph &&
 285                 corrupt_file "$base_file" $(test_oid shallow) "\01" &&
 286                 test_must_fail git commit-graph verify --shallow 2>test_err &&
 287                 grep -v "^+" test_err >err &&
 288                 test_grep "incorrect checksum" err
 289         )
 290 '
 291
 292 test_expect_success 'verify notices chain slice which is bogus (base)' '
 293         git clone --no-hardlinks . verify-chain-bogus-base &&
 294         (
 295                 cd verify-chain-bogus-base &&
 296                 git commit-graph verify &&
 297                 base_file=$graphdir/graph-$(sed -n 1p $graphdir/commit-graph-chain).graph &&
 298                 echo "garbage" >$base_file &&
 299                 test_must_fail git commit-graph verify 2>test_err &&
 300                 grep -v "^+" test_err >err &&
 301                 grep "commit-graph file is too small" err
 302         )
 303 '
 304
 305 test_expect_success 'verify notices chain slice which is bogus (tip)' '
 306         git clone --no-hardlinks . verify-chain-bogus-tip &&
 307         (
 308                 cd verify-chain-bogus-tip &&
 309                 git commit-graph verify &&
 310                 tip_file=$graphdir/graph-$(sed -n 2p $graphdir/commit-graph-chain).graph &&
 311                 echo "garbage" >$tip_file &&
 312                 test_must_fail git commit-graph verify 2>test_err &&
 313                 grep -v "^+" test_err >err &&
 314                 grep "commit-graph file is too small" err
 315         )
 316 '
 317
 318 test_expect_success 'verify --shallow does not check base contents' '
 319         git clone --no-hardlinks . verify-shallow &&
 320         (
 321                 cd verify-shallow &&
 322                 git commit-graph verify &&
 323                 base_file=$graphdir/graph-$(head -n 1 $graphdir/commit-graph-chain).graph &&
 324                 corrupt_file "$base_file" 1500 "\01" &&
 325                 git commit-graph verify --shallow &&
 326                 test_must_fail git commit-graph verify 2>test_err &&
 327                 grep -v "^+" test_err >err &&
 328                 test_grep "incorrect checksum" err
 329         )
 330 '
 331
 332 test_expect_success 'warn on base graph chunk incorrect' '
 333         git clone --no-hardlinks . base-chunk &&
 334         (
 335                 cd base-chunk &&
 336                 git commit-graph verify &&
 337                 base_file=$graphdir/graph-$(tail -n 1 $graphdir/commit-graph-chain).graph &&
 338                 corrupt_file "$base_file" $(test_oid base) "\01" &&
 339                 test_must_fail git commit-graph verify --shallow 2>test_err &&
 340                 grep -v "^+" test_err >err &&
 341                 test_grep "commit-graph chain does not match" err
 342         )
 343 '
 344
 345 test_expect_success 'verify after commit-graph-chain corruption (base)' '
 346         git clone --no-hardlinks . verify-chain-base &&
 347         (
 348                 cd verify-chain-base &&
 349                 corrupt_file "$graphdir/commit-graph-chain" 30 "G" &&
 350                 test_must_fail git commit-graph verify 2>test_err &&
 351                 grep -v "^+" test_err >err &&
 352                 test_grep "invalid commit-graph chain" err &&
 353                 corrupt_file "$graphdir/commit-graph-chain" 30 "A" &&
 354                 test_must_fail git commit-graph verify 2>test_err &&
 355                 grep -v "^+" test_err >err &&
 356                 test_grep "unable to find all commit-graph files" err
 357         )
 358 '
 359
 360 test_expect_success 'verify after commit-graph-chain corruption (tip)' '
 361         git clone --no-hardlinks . verify-chain-tip &&
 362         (
 363                 cd verify-chain-tip &&
 364                 corrupt_file "$graphdir/commit-graph-chain" 70 "G" &&
 365                 test_must_fail git commit-graph verify 2>test_err &&
 366                 grep -v "^+" test_err >err &&
 367                 test_grep "invalid commit-graph chain" err &&
 368                 corrupt_file "$graphdir/commit-graph-chain" 70 "A" &&
 369                 test_must_fail git commit-graph verify 2>test_err &&
 370                 grep -v "^+" test_err >err &&
 371                 test_grep "unable to find all commit-graph files" err
 372         )
 373 '
 374
 375 test_expect_success 'verify notices too-short chain file' '
 376         git clone --no-hardlinks . verify-chain-short &&
 377         (
 378                 cd verify-chain-short &&
 379                 git commit-graph verify &&
 380                 echo "garbage" >$graphdir/commit-graph-chain &&
 381                 test_must_fail git commit-graph verify 2>test_err &&
 382                 grep -v "^+" test_err >err &&
 383                 grep "commit-graph chain file too small" err
 384         )
 385 '
 386
 387 test_expect_success 'verify across alternates' '
 388         git clone --no-hardlinks . verify-alt &&
 389         (
 390                 cd verify-alt &&
 391                 rm -rf $graphdir &&
 392                 altdir="$(pwd)/../.git/objects" &&
 393                 echo "$altdir" >.git/objects/info/alternates &&
 394                 git commit-graph verify --object-dir="$altdir/" &&
 395                 test_commit extra &&
 396                 git commit-graph write --reachable --split &&
 397                 tip_file=$graphdir/graph-$(tail -n 1 $graphdir/commit-graph-chain).graph &&
 398                 corrupt_file "$tip_file" 1500 "\01" &&
 399                 test_must_fail git commit-graph verify --shallow 2>test_err &&
 400                 grep -v "^+" test_err >err &&
 401                 test_grep "incorrect checksum" err
 402         )
 403 '
 404
 405 test_expect_success 'reader bounds-checks base-graph chunk' '
 406         git clone --no-hardlinks . corrupt-base-chunk &&
 407         (
 408                 cd corrupt-base-chunk &&
 409                 tip_file=$graphdir/graph-$(tail -n 1 $graphdir/commit-graph-chain).graph &&
 410                 corrupt_chunk_file "$tip_file" BASE clear 01020304 &&
 411                 git -c core.commitGraph=false log >expect.out &&
 412                 git -c core.commitGraph=true log >out 2>err &&
 413                 test_cmp expect.out out &&
 414                 grep "commit-graph base graphs chunk is too small" err
 415         )
 416 '
 417
 418 test_expect_success 'add octopus merge' '
 419         git reset --hard commits/10 &&
 420         git merge commits/3 commits/4 &&
 421         git branch merge/octopus &&
 422         git commit-graph write --reachable --split &&
 423         git commit-graph verify --progress 2>err &&
 424         test_line_count = 1 err &&
 425         grep "Verifying commits in commit graph: 100% (18/18)" err &&
 426         test_grep ! warning err &&
 427         test_line_count = 3 $graphdir/commit-graph-chain
 428 '
 429
 430 graph_git_behavior 'graph exists' merge/octopus commits/12
 431
 432 test_expect_success 'split across alternate where alternate is not split' '
 433         git commit-graph write --reachable &&
 434         test_path_is_file .git/objects/info/commit-graph &&
 435         cp .git/objects/info/commit-graph . &&
 436         git clone --no-hardlinks . alt-split &&
 437         (
 438                 cd alt-split &&
 439                 rm -f .git/objects/info/commit-graph &&
 440                 echo "$(pwd)"/../.git/objects >.git/objects/info/alternates &&
 441                 test_commit 18 &&
 442                 git commit-graph write --reachable --split &&
 443                 test_line_count = 1 $graphdir/commit-graph-chain
 444         ) &&
 445         test_cmp commit-graph .git/objects/info/commit-graph
 446 '
 447
 448 test_expect_success '--split=no-merge always writes an incremental' '
 449         test_when_finished rm -rf a b &&
 450         rm -rf $graphdir $infodir/commit-graph &&
 451         git reset --hard commits/2 &&
 452         git rev-list HEAD~1 >a &&
 453         git rev-list HEAD >b &&
 454         git commit-graph write --split --stdin-commits <a &&
 455         git commit-graph write --split=no-merge --stdin-commits <b &&
 456         test_line_count = 2 $graphdir/commit-graph-chain
 457 '
 458
 459 test_expect_success '--split=replace replaces the chain' '
 460         rm -rf $graphdir $infodir/commit-graph &&
 461         git reset --hard commits/3 &&
 462         git rev-list -1 HEAD~2 >a &&
 463         git rev-list -1 HEAD~1 >b &&
 464         git rev-list -1 HEAD >c &&
 465         git commit-graph write --split=no-merge --stdin-commits <a &&
 466         git commit-graph write --split=no-merge --stdin-commits <b &&
 467         git commit-graph write --split=no-merge --stdin-commits <c &&
 468         test_line_count = 3 $graphdir/commit-graph-chain &&
 469         git commit-graph write --stdin-commits --split=replace <b &&
 470         test_path_is_missing $infodir/commit-graph &&
 471         test_path_is_file $graphdir/commit-graph-chain &&
 472         ls $graphdir/graph-*.graph >graph-files &&
 473         test_line_count = 1 graph-files &&
 474         verify_chain_files_exist $graphdir &&
 475         graph_read_expect 2
 476 '
 477
 478 test_expect_success ULIMIT_FILE_DESCRIPTORS 'handles file descriptor exhaustion' '
 479         git init ulimit &&
 480         (
 481                 cd ulimit &&
 482                 for i in $(test_seq 64)
 483                 do
 484                         test_commit $i &&
 485                         run_with_limited_open_files test_might_fail git commit-graph write \
 486                                 --split=no-merge --reachable || return 1
 487                 done
 488         )
 489 '
 490
 491 while read mode modebits
 492 do
 493         test_expect_success POSIXPERM "split commit-graph respects core.sharedrepository $mode" '
 494                 rm -rf $graphdir $infodir/commit-graph &&
 495                 git reset --hard commits/1 &&
 496                 test_config core.sharedrepository "$mode" &&
 497                 git commit-graph write --split --reachable &&
 498                 ls $graphdir/graph-*.graph >graph-files &&
 499                 test_line_count = 1 graph-files &&
 500                 echo "$modebits" >expect &&
 501                 test_modebits $graphdir/graph-*.graph >actual &&
 502                 test_cmp expect actual &&
 503                 test_modebits $graphdir/commit-graph-chain >actual &&
 504                 test_cmp expect actual
 505         '
 506 done <<\EOF
 507 0666 -r--r--r--
 508 0600 -r--------
 509 EOF
 510
 511 test_expect_success '--split=replace with partial Bloom data' '
 512         rm -rf $graphdir $infodir/commit-graph &&
 513         git reset --hard commits/3 &&
 514         git rev-list -1 HEAD~2 >a &&
 515         git rev-list -1 HEAD~1 >b &&
 516         git commit-graph write --split=no-merge --stdin-commits --changed-paths <a &&
 517         git commit-graph write --split=no-merge --stdin-commits <b &&
 518         git commit-graph write --split=replace --stdin-commits --changed-paths <c &&
 519         ls $graphdir/graph-*.graph >graph-files &&
 520         test_line_count = 1 graph-files &&
 521         verify_chain_files_exist $graphdir
 522 '
 523
 524 test_expect_success 'prevent regression for duplicate commits across layers' '
 525         git init dup &&
 526         git -C dup commit --allow-empty -m one &&
 527         git -C dup -c core.commitGraph=false commit-graph write --split=no-merge --reachable 2>err &&
 528         test_grep "attempting to write a commit-graph" err &&
 529         git -C dup commit-graph write --split=no-merge --reachable &&
 530         git -C dup commit --allow-empty -m two &&
 531         git -C dup commit-graph write --split=no-merge --reachable &&
 532         git -C dup commit --allow-empty -m three &&
 533         git -C dup commit-graph write --split --reachable &&
 534         git -C dup commit-graph verify
 535 '
 536
 537 NUM_FIRST_LAYER_COMMITS=64
 538 NUM_SECOND_LAYER_COMMITS=16
 539 NUM_THIRD_LAYER_COMMITS=7
 540 NUM_FOURTH_LAYER_COMMITS=8
 541 NUM_FIFTH_LAYER_COMMITS=16
 542 SECOND_LAYER_SEQUENCE_START=$(($NUM_FIRST_LAYER_COMMITS + 1))
 543 SECOND_LAYER_SEQUENCE_END=$(($SECOND_LAYER_SEQUENCE_START + $NUM_SECOND_LAYER_COMMITS - 1))
 544 THIRD_LAYER_SEQUENCE_START=$(($SECOND_LAYER_SEQUENCE_END + 1))
 545 THIRD_LAYER_SEQUENCE_END=$(($THIRD_LAYER_SEQUENCE_START + $NUM_THIRD_LAYER_COMMITS - 1))
 546 FOURTH_LAYER_SEQUENCE_START=$(($THIRD_LAYER_SEQUENCE_END + 1))
 547 FOURTH_LAYER_SEQUENCE_END=$(($FOURTH_LAYER_SEQUENCE_START + $NUM_FOURTH_LAYER_COMMITS - 1))
 548 FIFTH_LAYER_SEQUENCE_START=$(($FOURTH_LAYER_SEQUENCE_END + 1))
 549 FIFTH_LAYER_SEQUENCE_END=$(($FIFTH_LAYER_SEQUENCE_START + $NUM_FIFTH_LAYER_COMMITS - 1))
 550
 551 # Current split graph chain:
 552 #
 553 #     16 commits (No GDAT)
 554 # ------------------------
 555 #     64 commits (GDAT)
 556 #
 557 test_expect_success 'setup repo for mixed generation commit-graph-chain' '
 558         graphdir=".git/objects/info/commit-graphs" &&
 559         test_oid_cache <<-EOF &&
 560         oid_version sha1:1
 561         oid_version sha256:2
 562         EOF
 563         git init mixed &&
 564         (
 565                 cd mixed &&
 566                 git config core.commitGraph true &&
 567                 git config gc.writeCommitGraph false &&
 568                 for i in $(test_seq $NUM_FIRST_LAYER_COMMITS)
 569                 do
 570                         test_commit $i &&
 571                         git branch commits/$i || return 1
 572                 done &&
 573                 git -c commitGraph.generationVersion=2 commit-graph write --reachable --split &&
 574                 graph_read_expect $NUM_FIRST_LAYER_COMMITS &&
 575                 test_line_count = 1 $graphdir/commit-graph-chain &&
 576                 for i in $(test_seq $SECOND_LAYER_SEQUENCE_START $SECOND_LAYER_SEQUENCE_END)
 577                 do
 578                         test_commit $i &&
 579                         git branch commits/$i || return 1
 580                 done &&
 581                 git -c commitGraph.generationVersion=1 commit-graph write --reachable --split=no-merge &&
 582                 test_line_count = 2 $graphdir/commit-graph-chain &&
 583                 test-tool read-graph >output &&
 584                 cat >expect <<-EOF &&
 585                 header: 43475048 1 $(test_oid oid_version) 4 1
 586                 num_commits: $NUM_SECOND_LAYER_COMMITS
 587                 chunks: oid_fanout oid_lookup commit_metadata
 588                 options:
 589                 EOF
 590                 test_cmp expect output &&
 591                 git commit-graph verify &&
 592                 cat $graphdir/commit-graph-chain
 593         )
 594 '
 595
 596 # The new layer will be added without generation data chunk as it was not
 597 # present on the layer underneath it.
 598 #
 599 #      7 commits (No GDAT)
 600 # ------------------------
 601 #     16 commits (No GDAT)
 602 # ------------------------
 603 #     64 commits (GDAT)
 604 #
 605 test_expect_success 'do not write generation data chunk if not present on existing tip' '
 606         git clone mixed mixed-no-gdat &&
 607         (
 608                 cd mixed-no-gdat &&
 609                 for i in $(test_seq $THIRD_LAYER_SEQUENCE_START $THIRD_LAYER_SEQUENCE_END)
 610                 do
 611                         test_commit $i &&
 612                         git branch commits/$i || return 1
 613                 done &&
 614                 git commit-graph write --reachable --split=no-merge &&
 615                 test_line_count = 3 $graphdir/commit-graph-chain &&
 616                 test-tool read-graph >output &&
 617                 cat >expect <<-EOF &&
 618                 header: 43475048 1 $(test_oid oid_version) 4 2
 619                 num_commits: $NUM_THIRD_LAYER_COMMITS
 620                 chunks: oid_fanout oid_lookup commit_metadata
 621                 options:
 622                 EOF
 623                 test_cmp expect output &&
 624                 git commit-graph verify
 625         )
 626 '
 627
 628 # Number of commits in each layer of the split-commit graph before merge:
 629 #
 630 #      8 commits (No GDAT)
 631 # ------------------------
 632 #      7 commits (No GDAT)
 633 # ------------------------
 634 #     16 commits (No GDAT)
 635 # ------------------------
 636 #     64 commits (GDAT)
 637 #
 638 # The top two layers are merged and do not have generation data chunk as layer below them does
 639 # not have generation data chunk.
 640 #
 641 #     15 commits (No GDAT)
 642 # ------------------------
 643 #     16 commits (No GDAT)
 644 # ------------------------
 645 #     64 commits (GDAT)
 646 #
 647 test_expect_success 'do not write generation data chunk if the topmost remaining layer does not have generation data chunk' '
 648         git clone mixed-no-gdat mixed-merge-no-gdat &&
 649         (
 650                 cd mixed-merge-no-gdat &&
 651                 for i in $(test_seq $FOURTH_LAYER_SEQUENCE_START $FOURTH_LAYER_SEQUENCE_END)
 652                 do
 653                         test_commit $i &&
 654                         git branch commits/$i || return 1
 655                 done &&
 656                 git commit-graph write --reachable --split --size-multiple 1 &&
 657                 test_line_count = 3 $graphdir/commit-graph-chain &&
 658                 test-tool read-graph >output &&
 659                 cat >expect <<-EOF &&
 660                 header: 43475048 1 $(test_oid oid_version) 4 2
 661                 num_commits: $(($NUM_THIRD_LAYER_COMMITS + $NUM_FOURTH_LAYER_COMMITS))
 662                 chunks: oid_fanout oid_lookup commit_metadata
 663                 options:
 664                 EOF
 665                 test_cmp expect output &&
 666                 git commit-graph verify
 667         )
 668 '
 669
 670 # Number of commits in each layer of the split-commit graph before merge:
 671 #
 672 #     16 commits (No GDAT)
 673 # ------------------------
 674 #     15 commits (No GDAT)
 675 # ------------------------
 676 #     16 commits (No GDAT)
 677 # ------------------------
 678 #     64 commits (GDAT)
 679 #
 680 # The top three layers are merged and has generation data chunk as the topmost remaining layer
 681 # has generation data chunk.
 682 #
 683 #     47 commits (GDAT)
 684 # ------------------------
 685 #     64 commits (GDAT)
 686 #
 687 test_expect_success 'write generation data chunk if topmost remaining layer has generation data chunk' '
 688         git clone mixed-merge-no-gdat mixed-merge-gdat &&
 689         (
 690                 cd mixed-merge-gdat &&
 691                 for i in $(test_seq $FIFTH_LAYER_SEQUENCE_START $FIFTH_LAYER_SEQUENCE_END)
 692                 do
 693                         test_commit $i &&
 694                         git branch commits/$i || return 1
 695                 done &&
 696                 git commit-graph write --reachable --split --size-multiple 1 &&
 697                 test_line_count = 2 $graphdir/commit-graph-chain &&
 698                 test-tool read-graph >output &&
 699                 cat >expect <<-EOF &&
 700                 header: 43475048 1 $(test_oid oid_version) 5 1
 701                 num_commits: $(($NUM_SECOND_LAYER_COMMITS + $NUM_THIRD_LAYER_COMMITS + $NUM_FOURTH_LAYER_COMMITS + $NUM_FIFTH_LAYER_COMMITS))
 702                 chunks: oid_fanout oid_lookup commit_metadata generation_data
 703                 options: read_generation_data
 704                 EOF
 705                 test_cmp expect output
 706         )
 707 '
 708
 709 test_expect_success 'write generation data chunk when commit-graph chain is replaced' '
 710         git clone mixed mixed-replace &&
 711         (
 712                 cd mixed-replace &&
 713                 git commit-graph write --reachable --split=replace &&
 714                 test_path_is_file $graphdir/commit-graph-chain &&
 715                 test_line_count = 1 $graphdir/commit-graph-chain &&
 716                 verify_chain_files_exist $graphdir &&
 717                 graph_read_expect $(($NUM_FIRST_LAYER_COMMITS + $NUM_SECOND_LAYER_COMMITS)) &&
 718                 git commit-graph verify
 719         )
 720 '
 721
 722 test_expect_success 'temporary graph layer is discarded upon failure' '
 723         git init layer-discard &&
 724         (
 725                 cd layer-discard &&
 726
 727                 test_commit A &&
 728                 test_commit B &&
 729
 730                 # Intentionally remove commit "A" from the object store
 731                 # so that the commit-graph machinery fails to parse the
 732                 # parents of "B".
 733                 #
 734                 # This takes place after the commit-graph machinery has
 735                 # initialized a new temporary file to store the contents
 736                 # of the new graph layer, so will allow us to ensure
 737                 # that the temporary file is discarded upon failure.
 738                 rm $objdir/$(test_oid_to_path $(git rev-parse HEAD^)) &&
 739
 740                 test_must_fail git commit-graph write --reachable --split &&
 741                 test_dir_is_empty $graphdir
 742         )
 743 '
 744
 745 test_done