t/t6036-recursive-corner-cases.sh

   1 #!/bin/sh
   2
   3 test_description='recursive merge corner cases involving criss-cross merges'
   4
   5 . ./test-lib.sh
   6
   7 #
   8 #  L1  L2
   9 #   o---o
  10 #  / \ / \
  11 # o   X   ?
  12 #  \ / \ /
  13 #   o---o
  14 #  R1  R2
  15 #
  16
  17 test_expect_success 'setup basic criss-cross + rename with no modifications' '
  18         test_create_repo basic-rename &&
  19         (
  20                 cd basic-rename &&
  21
  22                 ten="0 1 2 3 4 5 6 7 8 9" &&
  23                 for i in $ten
  24                 do
  25                         echo line $i in a sample file
  26                 done >one &&
  27                 for i in $ten
  28                 do
  29                         echo line $i in another sample file
  30                 done >two &&
  31                 git add one two &&
  32                 test_tick && git commit -m initial &&
  33
  34                 git branch L1 &&
  35                 git checkout -b R1 &&
  36                 git mv one three &&
  37                 test_tick && git commit -m R1 &&
  38
  39                 git checkout L1 &&
  40                 git mv two three &&
  41                 test_tick && git commit -m L1 &&
  42
  43                 git checkout L1^0 &&
  44                 test_tick && git merge -s ours R1 &&
  45                 git tag L2 &&
  46
  47                 git checkout R1^0 &&
  48                 test_tick && git merge -s ours L1 &&
  49                 git tag R2
  50         )
  51 '
  52
  53 test_expect_success 'merge simple rename+criss-cross with no modifications' '
  54         (
  55                 cd basic-rename &&
  56
  57                 git reset --hard &&
  58                 git checkout L2^0 &&
  59
  60                 test_must_fail git merge -s recursive R2^0 &&
  61
  62                 git ls-files -s >out &&
  63                 test_line_count = 2 out &&
  64                 git ls-files -u >out &&
  65                 test_line_count = 2 out &&
  66                 git ls-files -o >out &&
  67                 test_line_count = 3 out &&
  68
  69                 git rev-parse >expect       \
  70                         L2:three   R2:three \
  71                         L2:three   R2:three &&
  72                 git rev-parse   >actual     \
  73                         :2:three   :3:three &&
  74                 git hash-object >>actual    \
  75                         three~HEAD three~R2^0 &&
  76                 test_cmp expect actual
  77         )
  78 '
  79
  80 #
  81 # Same as before, but modify L1 slightly:
  82 #
  83 #  L1m L2
  84 #   o---o
  85 #  / \ / \
  86 # o   X   ?
  87 #  \ / \ /
  88 #   o---o
  89 #  R1  R2
  90 #
  91
  92 test_expect_success 'setup criss-cross + rename merges with basic modification' '
  93         test_create_repo rename-modify &&
  94         (
  95                 cd rename-modify &&
  96
  97                 ten="0 1 2 3 4 5 6 7 8 9" &&
  98                 for i in $ten
  99                 do
 100                         echo line $i in a sample file
 101                 done >one &&
 102                 for i in $ten
 103                 do
 104                         echo line $i in another sample file
 105                 done >two &&
 106                 git add one two &&
 107                 test_tick && git commit -m initial &&
 108
 109                 git branch L1 &&
 110                 git checkout -b R1 &&
 111                 git mv one three &&
 112                 echo more >>two &&
 113                 git add two &&
 114                 test_tick && git commit -m R1 &&
 115
 116                 git checkout L1 &&
 117                 git mv two three &&
 118                 test_tick && git commit -m L1 &&
 119
 120                 git checkout L1^0 &&
 121                 test_tick && git merge -s ours R1 &&
 122                 git tag L2 &&
 123
 124                 git checkout R1^0 &&
 125                 test_tick && git merge -s ours L1 &&
 126                 git tag R2
 127         )
 128 '
 129
 130 test_expect_success 'merge criss-cross + rename merges with basic modification' '
 131         (
 132                 cd rename-modify &&
 133
 134                 git checkout L2^0 &&
 135
 136                 test_must_fail git merge -s recursive R2^0 &&
 137
 138                 git ls-files -s >out &&
 139                 test_line_count = 2 out &&
 140                 git ls-files -u >out &&
 141                 test_line_count = 2 out &&
 142                 git ls-files -o >out &&
 143                 test_line_count = 3 out &&
 144
 145                 git rev-parse >expect       \
 146                         L2:three   R2:three \
 147                         L2:three   R2:three &&
 148                 git rev-parse   >actual     \
 149                         :2:three   :3:three &&
 150                 git hash-object >>actual    \
 151                         three~HEAD three~R2^0 &&
 152                 test_cmp expect actual
 153         )
 154 '
 155
 156 #
 157 # For the next test, we start with three commits in two lines of development
 158 # which setup a rename/add conflict:
 159 #   Commit A: File 'a' exists
 160 #   Commit B: Rename 'a' -> 'new_a'
 161 #   Commit C: Modify 'a', create different 'new_a'
 162 # Later, two different people merge and resolve differently:
 163 #   Commit D: Merge B & C, ignoring separately created 'new_a'
 164 #   Commit E: Merge B & C making use of some piece of secondary 'new_a'
 165 # Finally, someone goes to merge D & E.  Does git detect the conflict?
 166 #
 167 #      B   D
 168 #      o---o
 169 #     / \ / \
 170 #  A o   X   ? F
 171 #     \ / \ /
 172 #      o---o
 173 #      C   E
 174 #
 175
 176 test_expect_success 'setup differently handled merges of rename/add conflict' '
 177         test_create_repo rename-add &&
 178         (
 179                 cd rename-add &&
 180
 181                 printf "0\n1\n2\n3\n4\n5\n6\n7\n8\n9\n" >a &&
 182                 git add a &&
 183                 test_tick && git commit -m A &&
 184
 185                 git branch B &&
 186                 git checkout -b C &&
 187                 echo 10 >>a &&
 188                 echo "other content" >>new_a &&
 189                 git add a new_a &&
 190                 test_tick && git commit -m C &&
 191
 192                 git checkout B &&
 193                 git mv a new_a &&
 194                 test_tick && git commit -m B &&
 195
 196                 git checkout B^0 &&
 197                 test_must_fail git merge C &&
 198                 git clean -f &&
 199                 test_tick && git commit -m D &&
 200                 git tag D &&
 201
 202                 git checkout C^0 &&
 203                 test_must_fail git merge B &&
 204                 rm new_a~HEAD new_a &&
 205                 printf "Incorrectly merged content" >>new_a &&
 206                 git add -u &&
 207                 test_tick && git commit -m E &&
 208                 git tag E
 209         )
 210 '
 211
 212 test_expect_success 'git detects differently handled merges conflict' '
 213         (
 214                 cd rename-add &&
 215
 216                 git checkout D^0 &&
 217
 218                 test_must_fail git merge -s recursive E^0 &&
 219
 220                 git ls-files -s >out &&
 221                 test_line_count = 3 out &&
 222                 git ls-files -u >out &&
 223                 test_line_count = 3 out &&
 224                 git ls-files -o >out &&
 225                 test_line_count = 1 out &&
 226
 227                 git rev-parse >expect       \
 228                         D:new_a  E:new_a &&
 229                 git rev-parse   >actual     \
 230                         :2:new_a :3:new_a &&
 231                 test_cmp expect actual &&
 232
 233                 git cat-file -p C:new_a >ours &&
 234                 git cat-file -p B:new_a >theirs &&
 235                 >empty &&
 236                 test_must_fail git merge-file \
 237                         -L "Temporary merge branch 1" \
 238                         -L "" \
 239                         -L "Temporary merge branch 2" \
 240                         ours empty theirs &&
 241                 sed -e "s/^\([<=>]\)/\1\1\1/" ours >expect &&
 242                 git cat-file -p :1:new_a >actual &&
 243                 test_cmp expect actual
 244         )
 245 '
 246
 247 #
 248 # criss-cross + modify/delete:
 249 #
 250 #      B   D
 251 #      o---o
 252 #     / \ / \
 253 #  A o   X   ? F
 254 #     \ / \ /
 255 #      o---o
 256 #      C   E
 257 #
 258 #   Commit A: file with contents 'A\n'
 259 #   Commit B: file with contents 'B\n'
 260 #   Commit C: file not present
 261 #   Commit D: file with contents 'B\n'
 262 #   Commit E: file not present
 263 #
 264 # Merging commits D & E should result in modify/delete conflict.
 265
 266 test_expect_success 'setup criss-cross + modify/delete resolved differently' '
 267         test_create_repo modify-delete &&
 268         (
 269                 cd modify-delete &&
 270
 271                 echo A >file &&
 272                 git add file &&
 273                 test_tick &&
 274                 git commit -m A &&
 275
 276                 git branch B &&
 277                 git checkout -b C &&
 278                 git rm file &&
 279                 test_tick &&
 280                 git commit -m C &&
 281
 282                 git checkout B &&
 283                 echo B >file &&
 284                 git add file &&
 285                 test_tick &&
 286                 git commit -m B &&
 287
 288                 git checkout B^0 &&
 289                 test_must_fail git merge C &&
 290                 echo B >file &&
 291                 git add file &&
 292                 test_tick &&
 293                 git commit -m D &&
 294                 git tag D &&
 295
 296                 git checkout C^0 &&
 297                 test_must_fail git merge B &&
 298                 git rm file &&
 299                 test_tick &&
 300                 git commit -m E &&
 301                 git tag E
 302         )
 303 '
 304
 305 test_expect_success 'git detects conflict merging criss-cross+modify/delete' '
 306         (
 307                 cd modify-delete &&
 308
 309                 git checkout D^0 &&
 310
 311                 test_must_fail git merge -s recursive E^0 &&
 312
 313                 git ls-files -s >out &&
 314                 test_line_count = 2 out &&
 315                 git ls-files -u >out &&
 316                 test_line_count = 2 out &&
 317
 318                 git rev-parse >expect       \
 319                         master:file  B:file &&
 320                 git rev-parse   >actual      \
 321                         :1:file      :2:file &&
 322                 test_cmp expect actual
 323         )
 324 '
 325
 326 test_expect_success 'git detects conflict merging criss-cross+modify/delete, reverse direction' '
 327         (
 328                 cd modify-delete &&
 329
 330                 git reset --hard &&
 331                 git checkout E^0 &&
 332
 333                 test_must_fail git merge -s recursive D^0 &&
 334
 335                 git ls-files -s >out &&
 336                 test_line_count = 2 out &&
 337                 git ls-files -u >out &&
 338                 test_line_count = 2 out &&
 339
 340                 git rev-parse >expect       \
 341                         master:file  B:file &&
 342                 git rev-parse   >actual      \
 343                         :1:file      :3:file &&
 344                 test_cmp expect actual
 345         )
 346 '
 347
 348 #      SORRY FOR THE SUPER LONG DESCRIPTION, BUT THIS NEXT ONE IS HAIRY
 349 #
 350 # criss-cross + d/f conflict via add/add:
 351 #   Commit A: Neither file 'a' nor directory 'a/' exists.
 352 #   Commit B: Introduce 'a'
 353 #   Commit C: Introduce 'a/file'
 354 #   Commit D1: Merge B & C, keeping 'a'    and deleting 'a/'
 355 #   Commit E1: Merge B & C, deleting 'a' but keeping 'a/file'
 356 #
 357 #      B   D1 or D2
 358 #      o---o
 359 #     / \ / \
 360 #  A o   X   ? F
 361 #     \ / \ /
 362 #      o---o
 363 #      C   E1 or E2 or E3
 364 #
 365 # I'll describe D2, E2, & E3 (which are alternatives for D1 & E1) more below...
 366 #
 367 # Merging D1 & E1 requires we first create a virtual merge base X from
 368 # merging A & B in memory.  There are several possibilities for the merge-base:
 369 #   1: Keep both 'a' and 'a/file' (assuming crazy filesystem allowing a tree
 370 #      with a directory and file at same path): results in merge of D1 & E1
 371 #      being clean with both files deleted.  Bad (no conflict detected).
 372 #   2: Keep 'a' but not 'a/file': Merging D1 & E1 is clean and matches E1.  Bad.
 373 #   3: Keep 'a/file' but not 'a': Merging D1 & E1 is clean and matches D1.  Bad.
 374 #   4: Keep neither file: Merging D1 & E1 reports the D/F add/add conflict.
 375 #
 376 # So 4 sounds good for this case, but if we were to merge D1 & E3, where E3
 377 # is defined as:
 378 #   Commit E3: Merge B & C, keeping modified a, and deleting a/
 379 # then we'd get an add/add conflict for 'a', which seems suboptimal.  A little
 380 # creativity leads us to an alternate choice:
 381 #   5: Keep 'a' as 'a~$UNIQUE' and a/file; results:
 382 #        Merge D1 & E1: rename/delete conflict for 'a'; a/file silently deleted
 383 #        Merge D1 & E3 is clean, as expected.
 384 #
 385 # So choice 5 at least provides some kind of conflict for the original case,
 386 # and can merge cleanly as expected with D1 and E3.  It also made things just
 387 # slightly funny for merging D1 and e$, where E4 is defined as:
 388 #   Commit E4: Merge B & C, modifying 'a' and renaming to 'a2', and deleting 'a/'
 389 # in this case, we'll get a rename/rename(1to2) conflict because a~$UNIQUE
 390 # gets renamed to 'a' in D1 and to 'a2' in E4.  But that's better than having
 391 # two files (both 'a' and 'a2') sitting around without the user being notified
 392 # that we could detect they were related and need to be merged.  Also, choice
 393 # 5 makes the handling of 'a/file' seem suboptimal.  What if we were to merge
 394 # D2 and E4, where D2 is:
 395 #   Commit D2: Merge B & C, renaming 'a'->'a2', keeping 'a/file'
 396 # This would result in a clean merge with 'a2' having three-way merged
 397 # contents (good), and deleting 'a/' (bad) -- it doesn't detect the
 398 # conflict in how the different sides treated a/file differently.
 399 # Continuing down the creative route:
 400 #   6: Keep 'a' as 'a~$UNIQUE1' and keep 'a/' as 'a~$UNIQUE2/'; results:
 401 #        Merge D1 & E1: rename/delete conflict for 'a' and each path under 'a/'.
 402 #        Merge D1 & E3: clean, as expected.
 403 #        Merge D1 & E4: rename/rename(1to2) conflict on 'a' vs 'a2'.
 404 #        Merge D2 & E4: clean for 'a2', rename/delete for a/file
 405 #
 406 # Choice 6 could cause rename detection to take longer (providing more targets
 407 # that need to be searched).  Also, the conflict message for each path under
 408 # 'a/' might be annoying unless we can detect it at the directory level, print
 409 # it once, and then suppress it for individual filepaths underneath.
 410 #
 411 #
 412 # As of time of writing, git uses choice 5.  Directory rename detection and
 413 # rename detection performance improvements might make choice 6 a desirable
 414 # improvement.  But we can at least document where we fall short for now...
 415 #
 416 #
 417 # Historically, this testcase also used:
 418 #   Commit E2: Merge B & C, deleting 'a' but keeping slightly modified 'a/file'
 419 # The merge of D1 & E2 is very similar to D1 & E1 -- it has similar issues for
 420 # path 'a', but should always result in a modify/delete conflict for path
 421 # 'a/file'.  These tests ran the two merges
 422 #   D1 & E1
 423 #   D1 & E2
 424 # in both directions, to check for directional issues with D/F conflict
 425 # handling. Later we added
 426 #   D1 & E3
 427 #   D1 & E4
 428 #   D2 & E4
 429 # for good measure, though we only ran those one way because we had pretty
 430 # good confidence in merge-recursive's directional handling of D/F issues.
 431 #
 432 # Just to summarize all the intermediate merge commits:
 433 #   Commit D1: Merge B & C, keeping a    and deleting a/
 434 #   Commit D2: Merge B & C, renaming a->a2, keeping a/file
 435 #   Commit E1: Merge B & C, deleting a but keeping a/file
 436 #   Commit E2: Merge B & C, deleting a but keeping slightly modified a/file
 437 #   Commit E3: Merge B & C, keeping modified a, and deleting a/
 438 #   Commit E4: Merge B & C, modifying 'a' and renaming to 'a2', and deleting 'a/'
 439 #
 440
 441 test_expect_success 'setup differently handled merges of directory/file conflict' '
 442         test_create_repo directory-file &&
 443         (
 444                 cd directory-file &&
 445
 446                 >ignore-me &&
 447                 git add ignore-me &&
 448                 test_tick &&
 449                 git commit -m A &&
 450                 git tag A &&
 451
 452                 git branch B &&
 453                 git checkout -b C &&
 454                 mkdir a &&
 455                 test_write_lines a b c d e f g >a/file &&
 456                 git add a/file &&
 457                 test_tick &&
 458                 git commit -m C &&
 459
 460                 git checkout B &&
 461                 test_write_lines 1 2 3 4 5 6 7 >a &&
 462                 git add a &&
 463                 test_tick &&
 464                 git commit -m B &&
 465
 466                 git checkout B^0 &&
 467                 git merge -s ours -m D1 C^0 &&
 468                 git tag D1 &&
 469
 470                 git checkout B^0 &&
 471                 test_must_fail git merge C^0 &&
 472                 git clean -fd &&
 473                 git rm -rf a/ &&
 474                 git rm a &&
 475                 git cat-file -p B:a >a2 &&
 476                 git add a2 &&
 477                 git commit -m D2 &&
 478                 git tag D2 &&
 479
 480                 git checkout C^0 &&
 481                 git merge -s ours -m E1 B^0 &&
 482                 git tag E1 &&
 483
 484                 git checkout C^0 &&
 485                 git merge -s ours -m E2 B^0 &&
 486                 test_write_lines a b c d e f g h >a/file &&
 487                 git add a/file &&
 488                 git commit --amend -C HEAD &&
 489                 git tag E2 &&
 490
 491                 git checkout C^0 &&
 492                 test_must_fail git merge B^0 &&
 493                 git clean -fd &&
 494                 git rm -rf a/ &&
 495                 test_write_lines 1 2 3 4 5 6 7 8 >a &&
 496                 git add a &&
 497                 git commit -m E3 &&
 498                 git tag E3 &&
 499
 500                 git checkout C^0 &&
 501                 test_must_fail git merge B^0 &&
 502                 git clean -fd &&
 503                 git rm -rf a/ &&
 504                 git rm a &&
 505                 test_write_lines 1 2 3 4 5 6 7 8 >a2 &&
 506                 git add a2 &&
 507                 git commit -m E4 &&
 508                 git tag E4
 509         )
 510 '
 511
 512 test_expect_success 'merge of D1 & E1 fails but has appropriate contents' '
 513         test_when_finished "git -C directory-file reset --hard" &&
 514         test_when_finished "git -C directory-file clean -fdqx" &&
 515         (
 516                 cd directory-file &&
 517
 518                 git checkout D1^0 &&
 519
 520                 test_must_fail git merge -s recursive E1^0 &&
 521
 522                 git ls-files -s >out &&
 523                 test_line_count = 2 out &&
 524                 git ls-files -u >out &&
 525                 test_line_count = 1 out &&
 526                 git ls-files -o >out &&
 527                 test_line_count = 1 out &&
 528
 529                 git rev-parse >expect    \
 530                         A:ignore-me  B:a &&
 531                 git rev-parse   >actual   \
 532                         :0:ignore-me :2:a &&
 533                 test_cmp expect actual
 534         )
 535 '
 536
 537 test_expect_success 'merge of E1 & D1 fails but has appropriate contents' '
 538         test_when_finished "git -C directory-file reset --hard" &&
 539         test_when_finished "git -C directory-file clean -fdqx" &&
 540         (
 541                 cd directory-file &&
 542
 543                 git checkout E1^0 &&
 544
 545                 test_must_fail git merge -s recursive D1^0 &&
 546
 547                 git ls-files -s >out &&
 548                 test_line_count = 2 out &&
 549                 git ls-files -u >out &&
 550                 test_line_count = 1 out &&
 551                 git ls-files -o >out &&
 552                 test_line_count = 1 out &&
 553
 554                 git rev-parse >expect    \
 555                         A:ignore-me  B:a &&
 556                 git rev-parse   >actual   \
 557                         :0:ignore-me :3:a &&
 558                 test_cmp expect actual
 559         )
 560 '
 561
 562 test_expect_success 'merge of D1 & E2 fails but has appropriate contents' '
 563         test_when_finished "git -C directory-file reset --hard" &&
 564         test_when_finished "git -C directory-file clean -fdqx" &&
 565         (
 566                 cd directory-file &&
 567
 568                 git checkout D1^0 &&
 569
 570                 test_must_fail git merge -s recursive E2^0 &&
 571
 572                 git ls-files -s >out &&
 573                 test_line_count = 4 out &&
 574                 git ls-files -u >out &&
 575                 test_line_count = 3 out &&
 576                 git ls-files -o >out &&
 577                 test_line_count = 2 out &&
 578
 579                 git rev-parse >expect    \
 580                         B:a   E2:a/file  C:a/file   A:ignore-me &&
 581                 git rev-parse   >actual   \
 582                         :2:a  :3:a/file  :1:a/file  :0:ignore-me &&
 583                 test_cmp expect actual &&
 584
 585                 test_path_is_file a~HEAD
 586         )
 587 '
 588
 589 test_expect_success 'merge of E2 & D1 fails but has appropriate contents' '
 590         test_when_finished "git -C directory-file reset --hard" &&
 591         test_when_finished "git -C directory-file clean -fdqx" &&
 592         (
 593                 cd directory-file &&
 594
 595                 git checkout E2^0 &&
 596
 597                 test_must_fail git merge -s recursive D1^0 &&
 598
 599                 git ls-files -s >out &&
 600                 test_line_count = 4 out &&
 601                 git ls-files -u >out &&
 602                 test_line_count = 3 out &&
 603                 git ls-files -o >out &&
 604                 test_line_count = 2 out &&
 605
 606                 git rev-parse >expect    \
 607                         B:a   E2:a/file  C:a/file   A:ignore-me &&
 608                 git rev-parse   >actual   \
 609                         :3:a  :2:a/file  :1:a/file  :0:ignore-me &&
 610                 test_cmp expect actual &&
 611
 612                 test_path_is_file a~D1^0
 613         )
 614 '
 615
 616 test_expect_success 'merge of D1 & E3 succeeds' '
 617         test_when_finished "git -C directory-file reset --hard" &&
 618         test_when_finished "git -C directory-file clean -fdqx" &&
 619         (
 620                 cd directory-file &&
 621
 622                 git checkout D1^0 &&
 623
 624                 git merge -s recursive E3^0 &&
 625
 626                 git ls-files -s >out &&
 627                 test_line_count = 2 out &&
 628                 git ls-files -u >out &&
 629                 test_line_count = 0 out &&
 630                 git ls-files -o >out &&
 631                 test_line_count = 1 out &&
 632
 633                 git rev-parse >expect    \
 634                         A:ignore-me  E3:a &&
 635                 git rev-parse   >actual   \
 636                         :0:ignore-me :0:a &&
 637                 test_cmp expect actual
 638         )
 639 '
 640
 641 test_expect_success 'merge of D1 & E4 notifies user a and a2 are related' '
 642         test_when_finished "git -C directory-file reset --hard" &&
 643         test_when_finished "git -C directory-file clean -fdqx" &&
 644         (
 645                 cd directory-file &&
 646
 647                 git checkout D1^0 &&
 648
 649                 test_must_fail git merge -s recursive E4^0 &&
 650
 651                 git ls-files -s >out &&
 652                 test_line_count = 4 out &&
 653                 git ls-files -u >out &&
 654                 test_line_count = 3 out &&
 655                 git ls-files -o >out &&
 656                 test_line_count = 1 out &&
 657
 658                 git rev-parse >expect                  \
 659                         A:ignore-me  B:a   D1:a  E4:a2 &&
 660                 git rev-parse   >actual                \
 661                         :0:ignore-me :1:a~Temporary\ merge\ branch\ 2  :2:a  :3:a2 &&
 662                 test_cmp expect actual
 663         )
 664 '
 665
 666 test_expect_failure 'merge of D2 & E4 merges a2s & reports conflict for a/file' '
 667         test_when_finished "git -C directory-file reset --hard" &&
 668         test_when_finished "git -C directory-file clean -fdqx" &&
 669         (
 670                 cd directory-file &&
 671
 672                 git checkout D2^0 &&
 673
 674                 test_must_fail git merge -s recursive E4^0 &&
 675
 676                 git ls-files -s >out &&
 677                 test_line_count = 3 out &&
 678                 git ls-files -u >out &&
 679                 test_line_count = 1 out &&
 680                 git ls-files -o >out &&
 681                 test_line_count = 1 out &&
 682
 683                 git rev-parse >expect                 \
 684                         A:ignore-me  E4:a2  D2:a/file &&
 685                 git rev-parse   >actual               \
 686                         :0:ignore-me :0:a2  :2:a/file &&
 687                 test_cmp expect actual
 688         )
 689 '
 690
 691 #
 692 # criss-cross with rename/rename(1to2)/modify followed by
 693 # rename/rename(2to1)/modify:
 694 #
 695 #      B   D
 696 #      o---o
 697 #     / \ / \
 698 #  A o   X   ? F
 699 #     \ / \ /
 700 #      o---o
 701 #      C   E
 702 #
 703 #   Commit A: new file: a
 704 #   Commit B: rename a->b, modifying by adding a line
 705 #   Commit C: rename a->c
 706 #   Commit D: merge B&C, resolving conflict by keeping contents in newname
 707 #   Commit E: merge B&C, resolving conflict similar to D but adding another line
 708 #
 709 # There is a conflict merging B & C, but one of filename not of file
 710 # content.  Whoever created D and E chose specific resolutions for that
 711 # conflict resolution.  Now, since: (1) there is no content conflict
 712 # merging B & C, (2) D does not modify that merged content further, and (3)
 713 # both D & E resolve the name conflict in the same way, the modification to
 714 # newname in E should not cause any conflicts when it is merged with D.
 715 # (Note that this can be accomplished by having the virtual merge base have
 716 # the merged contents of b and c stored in a file named a, which seems like
 717 # the most logical choice anyway.)
 718 #
 719 # Comment from Junio: I do not necessarily agree with the choice "a", but
 720 # it feels sound to say "B and C do not agree what the final pathname
 721 # should be, but we know this content was derived from the common A:a so we
 722 # use one path whose name is arbitrary in the virtual merge base X between
 723 # D and E" and then further let the rename detection to notice that that
 724 # arbitrary path gets renamed between X-D to "newname" and X-E also to
 725 # "newname" to resolve it as both sides renaming it to the same new
 726 # name. It is akin to what we do at the content level, i.e. "B and C do not
 727 # agree what the final contents should be, so we leave the conflict marker
 728 # but that may cancel out at the final merge stage".
 729
 730 test_expect_success 'setup rename/rename(1to2)/modify followed by what looks like rename/rename(2to1)/modify' '
 731         test_create_repo rename-squared-squared &&
 732         (
 733                 cd rename-squared-squared &&
 734
 735                 printf "1\n2\n3\n4\n5\n6\n" >a &&
 736                 git add a &&
 737                 git commit -m A &&
 738                 git tag A &&
 739
 740                 git checkout -b B A &&
 741                 git mv a b &&
 742                 echo 7 >>b &&
 743                 git add -u &&
 744                 git commit -m B &&
 745
 746                 git checkout -b C A &&
 747                 git mv a c &&
 748                 git commit -m C &&
 749
 750                 git checkout -q B^0 &&
 751                 git merge --no-commit -s ours C^0 &&
 752                 git mv b newname &&
 753                 git commit -m "Merge commit C^0 into HEAD" &&
 754                 git tag D &&
 755
 756                 git checkout -q C^0 &&
 757                 git merge --no-commit -s ours B^0 &&
 758                 git mv c newname &&
 759                 printf "7\n8\n" >>newname &&
 760                 git add -u &&
 761                 git commit -m "Merge commit B^0 into HEAD" &&
 762                 git tag E
 763         )
 764 '
 765
 766 test_expect_success 'handle rename/rename(1to2)/modify followed by what looks like rename/rename(2to1)/modify' '
 767         (
 768                 cd rename-squared-squared &&
 769
 770                 git checkout D^0 &&
 771
 772                 git merge -s recursive E^0 &&
 773
 774                 git ls-files -s >out &&
 775                 test_line_count = 1 out &&
 776                 git ls-files -u >out &&
 777                 test_line_count = 0 out &&
 778                 git ls-files -o >out &&
 779                 test_line_count = 1 out &&
 780
 781                 test $(git rev-parse HEAD:newname) = $(git rev-parse E:newname)
 782         )
 783 '
 784
 785 #
 786 # criss-cross with rename/rename(1to2)/add-source + resolvable modify/modify:
 787 #
 788 #      B   D
 789 #      o---o
 790 #     / \ / \
 791 #  A o   X   ? F
 792 #     \ / \ /
 793 #      o---o
 794 #      C   E
 795 #
 796 #   Commit A: new file: a
 797 #   Commit B: rename a->b
 798 #   Commit C: rename a->c, add different a
 799 #   Commit D: merge B&C, keeping b&c and (new) a modified at beginning
 800 #   Commit E: merge B&C, keeping b&c and (new) a modified at end
 801 #
 802 # Merging commits D & E should result in no conflict; doing so correctly
 803 # requires getting the virtual merge base (from merging B&C) right, handling
 804 # renaming carefully (both in the virtual merge base and later), and getting
 805 # content merge handled.
 806
 807 test_expect_success 'setup criss-cross + rename/rename/add-source + modify/modify' '
 808         test_create_repo rename-rename-add-source &&
 809         (
 810                 cd rename-rename-add-source &&
 811
 812                 printf "lots\nof\nwords\nand\ncontent\n" >a &&
 813                 git add a &&
 814                 git commit -m A &&
 815                 git tag A &&
 816
 817                 git checkout -b B A &&
 818                 git mv a b &&
 819                 git commit -m B &&
 820
 821                 git checkout -b C A &&
 822                 git mv a c &&
 823                 printf "2\n3\n4\n5\n6\n7\n" >a &&
 824                 git add a &&
 825                 git commit -m C &&
 826
 827                 git checkout B^0 &&
 828                 git merge --no-commit -s ours C^0 &&
 829                 git checkout C -- a c &&
 830                 mv a old_a &&
 831                 echo 1 >a &&
 832                 cat old_a >>a &&
 833                 rm old_a &&
 834                 git add -u &&
 835                 git commit -m "Merge commit C^0 into HEAD" &&
 836                 git tag D &&
 837
 838                 git checkout C^0 &&
 839                 git merge --no-commit -s ours B^0 &&
 840                 git checkout B -- b &&
 841                 echo 8 >>a &&
 842                 git add -u &&
 843                 git commit -m "Merge commit B^0 into HEAD" &&
 844                 git tag E
 845         )
 846 '
 847
 848 test_expect_failure 'detect rename/rename/add-source for virtual merge-base' '
 849         (
 850                 cd rename-rename-add-source &&
 851
 852                 git checkout D^0 &&
 853
 854                 git merge -s recursive E^0 &&
 855
 856                 git ls-files -s >out &&
 857                 test_line_count = 3 out &&
 858                 git ls-files -u >out &&
 859                 test_line_count = 0 out &&
 860                 git ls-files -o >out &&
 861                 test_line_count = 1 out &&
 862
 863                 printf "1\n2\n3\n4\n5\n6\n7\n8\n" >correct &&
 864                 git rev-parse >expect \
 865                         A:a   A:a     \
 866                         correct       &&
 867                 git rev-parse   >actual  \
 868                         :0:b  :0:c       &&
 869                 git hash-object >>actual \
 870                         a                &&
 871                 test_cmp expect actual
 872         )
 873 '
 874
 875 #
 876 # criss-cross with rename/rename(1to2)/add-dest + simple modify:
 877 #
 878 #      B   D
 879 #      o---o
 880 #     / \ / \
 881 #  A o   X   ? F
 882 #     \ / \ /
 883 #      o---o
 884 #      C   E
 885 #
 886 #   Commit A: new file: a
 887 #   Commit B: rename a->b, add c
 888 #   Commit C: rename a->c
 889 #   Commit D: merge B&C, keeping A:a and B:c
 890 #   Commit E: merge B&C, keeping A:a and slightly modified c from B
 891 #
 892 # Merging commits D & E should result in no conflict.  The virtual merge
 893 # base of B & C needs to not delete B:c for that to work, though...
 894
 895 test_expect_success 'setup criss-cross+rename/rename/add-dest + simple modify' '
 896         test_create_repo rename-rename-add-dest &&
 897         (
 898                 cd rename-rename-add-dest &&
 899
 900                 >a &&
 901                 git add a &&
 902                 git commit -m A &&
 903                 git tag A &&
 904
 905                 git checkout -b B A &&
 906                 git mv a b &&
 907                 printf "1\n2\n3\n4\n5\n6\n7\n" >c &&
 908                 git add c &&
 909                 git commit -m B &&
 910
 911                 git checkout -b C A &&
 912                 git mv a c &&
 913                 git commit -m C &&
 914
 915                 git checkout B^0 &&
 916                 git merge --no-commit -s ours C^0 &&
 917                 git mv b a &&
 918                 git commit -m "D is like B but renames b back to a" &&
 919                 git tag D &&
 920
 921                 git checkout B^0 &&
 922                 git merge --no-commit -s ours C^0 &&
 923                 git mv b a &&
 924                 echo 8 >>c &&
 925                 git add c &&
 926                 git commit -m "E like D but has mod in c" &&
 927                 git tag E
 928         )
 929 '
 930
 931 test_expect_success 'virtual merge base handles rename/rename(1to2)/add-dest' '
 932         (
 933                 cd rename-rename-add-dest &&
 934
 935                 git checkout D^0 &&
 936
 937                 git merge -s recursive E^0 &&
 938
 939                 git ls-files -s >out &&
 940                 test_line_count = 2 out &&
 941                 git ls-files -u >out &&
 942                 test_line_count = 0 out &&
 943                 git ls-files -o >out &&
 944                 test_line_count = 1 out &&
 945
 946                 git rev-parse >expect \
 947                         A:a   E:c     &&
 948                 git rev-parse   >actual \
 949                         :0:a  :0:c      &&
 950                 test_cmp expect actual
 951         )
 952 '
 953
 954 #
 955 # criss-cross with modify/modify on a symlink:
 956 #
 957 #      B   D
 958 #      o---o
 959 #     / \ / \
 960 #  A o   X   ? F
 961 #     \ / \ /
 962 #      o---o
 963 #      C   E
 964 #
 965 #   Commit A: simple simlink fickle->lagoon
 966 #   Commit B: redirect fickle->disneyland
 967 #   Commit C: redirect fickle->home
 968 #   Commit D: merge B&C, resolving in favor of B
 969 #   Commit E: merge B&C, resolving in favor of C
 970 #
 971 # This is an obvious modify/modify conflict for the symlink 'fickle'.  Can
 972 # git detect it?
 973
 974 test_expect_success 'setup symlink modify/modify' '
 975         test_create_repo symlink-modify-modify &&
 976         (
 977                 cd symlink-modify-modify &&
 978
 979                 test_ln_s_add lagoon fickle &&
 980                 git commit -m A &&
 981                 git tag A &&
 982
 983                 git checkout -b B A &&
 984                 git rm fickle &&
 985                 test_ln_s_add disneyland fickle &&
 986                 git commit -m B &&
 987
 988                 git checkout -b C A &&
 989                 git rm fickle &&
 990                 test_ln_s_add home fickle &&
 991                 git add fickle &&
 992                 git commit -m C &&
 993
 994                 git checkout -q B^0 &&
 995                 git merge -s ours -m D C^0 &&
 996                 git tag D &&
 997
 998                 git checkout -q C^0 &&
 999                 git merge -s ours -m E B^0 &&
1000                 git tag E
1001         )
1002 '
1003
1004 test_expect_failure 'check symlink modify/modify' '
1005         (
1006                 cd symlink-modify-modify &&
1007
1008                 git checkout D^0 &&
1009
1010                 test_must_fail git merge -s recursive E^0 &&
1011
1012                 git ls-files -s >out &&
1013                 test_line_count = 3 out &&
1014                 git ls-files -u >out &&
1015                 test_line_count = 3 out &&
1016                 git ls-files -o >out &&
1017                 test_line_count = 1 out
1018         )
1019 '
1020
1021 #
1022 # criss-cross with add/add of a symlink:
1023 #
1024 #      B   D
1025 #      o---o
1026 #     / \ / \
1027 #  A o   X   ? F
1028 #     \ / \ /
1029 #      o---o
1030 #      C   E
1031 #
1032 #   Commit A: No symlink or path exists yet
1033 #   Commit B: set up symlink: fickle->disneyland
1034 #   Commit C: set up symlink: fickle->home
1035 #   Commit D: merge B&C, resolving in favor of B
1036 #   Commit E: merge B&C, resolving in favor of C
1037 #
1038 # This is an obvious add/add conflict for the symlink 'fickle'.  Can
1039 # git detect it?
1040
1041 test_expect_success 'setup symlink add/add' '
1042         test_create_repo symlink-add-add &&
1043         (
1044                 cd symlink-add-add &&
1045
1046                 touch ignoreme &&
1047                 git add ignoreme &&
1048                 git commit -m A &&
1049                 git tag A &&
1050
1051                 git checkout -b B A &&
1052                 test_ln_s_add disneyland fickle &&
1053                 git commit -m B &&
1054
1055                 git checkout -b C A &&
1056                 test_ln_s_add home fickle &&
1057                 git add fickle &&
1058                 git commit -m C &&
1059
1060                 git checkout -q B^0 &&
1061                 git merge -s ours -m D C^0 &&
1062                 git tag D &&
1063
1064                 git checkout -q C^0 &&
1065                 git merge -s ours -m E B^0 &&
1066                 git tag E
1067         )
1068 '
1069
1070 test_expect_failure 'check symlink add/add' '
1071         (
1072                 cd symlink-add-add &&
1073
1074                 git checkout D^0 &&
1075
1076                 test_must_fail git merge -s recursive E^0 &&
1077
1078                 git ls-files -s >out &&
1079                 test_line_count = 2 out &&
1080                 git ls-files -u >out &&
1081                 test_line_count = 2 out &&
1082                 git ls-files -o >out &&
1083                 test_line_count = 1 out
1084         )
1085 '
1086
1087 #
1088 # criss-cross with modify/modify on a submodule:
1089 #
1090 #      B   D
1091 #      o---o
1092 #     / \ / \
1093 #  A o   X   ? F
1094 #     \ / \ /
1095 #      o---o
1096 #      C   E
1097 #
1098 #   Commit A: simple submodule repo
1099 #   Commit B: update repo
1100 #   Commit C: update repo differently
1101 #   Commit D: merge B&C, resolving in favor of B
1102 #   Commit E: merge B&C, resolving in favor of C
1103 #
1104 # This is an obvious modify/modify conflict for the submodule 'repo'.  Can
1105 # git detect it?
1106
1107 test_expect_success 'setup submodule modify/modify' '
1108         test_create_repo submodule-modify-modify &&
1109         (
1110                 cd submodule-modify-modify &&
1111
1112                 test_create_repo submod &&
1113                 (
1114                         cd submod &&
1115                         touch file-A &&
1116                         git add file-A &&
1117                         git commit -m A &&
1118                         git tag A &&
1119
1120                         git checkout -b B A &&
1121                         touch file-B &&
1122                         git add file-B &&
1123                         git commit -m B &&
1124                         git tag B &&
1125
1126                         git checkout -b C A &&
1127                         touch file-C &&
1128                         git add file-C &&
1129                         git commit -m C &&
1130                         git tag C
1131                 ) &&
1132
1133                 git -C submod reset --hard A &&
1134                 git add submod &&
1135                 git commit -m A &&
1136                 git tag A &&
1137
1138                 git checkout -b B A &&
1139                 git -C submod reset --hard B &&
1140                 git add submod &&
1141                 git commit -m B &&
1142
1143                 git checkout -b C A &&
1144                 git -C submod reset --hard C &&
1145                 git add submod &&
1146                 git commit -m C &&
1147
1148                 git checkout -q B^0 &&
1149                 git merge -s ours -m D C^0 &&
1150                 git tag D &&
1151
1152                 git checkout -q C^0 &&
1153                 git merge -s ours -m E B^0 &&
1154                 git tag E
1155         )
1156 '
1157
1158 test_expect_failure 'check submodule modify/modify' '
1159         (
1160                 cd submodule-modify-modify &&
1161
1162                 git checkout D^0 &&
1163
1164                 test_must_fail git merge -s recursive E^0 &&
1165
1166                 git ls-files -s >out &&
1167                 test_line_count = 3 out &&
1168                 git ls-files -u >out &&
1169                 test_line_count = 3 out &&
1170                 git ls-files -o >out &&
1171                 test_line_count = 1 out
1172         )
1173 '
1174
1175 #
1176 # criss-cross with add/add on a submodule:
1177 #
1178 #      B   D
1179 #      o---o
1180 #     / \ / \
1181 #  A o   X   ? F
1182 #     \ / \ /
1183 #      o---o
1184 #      C   E
1185 #
1186 #   Commit A: nothing of note
1187 #   Commit B: introduce submodule repo
1188 #   Commit C: introduce submodule repo at different commit
1189 #   Commit D: merge B&C, resolving in favor of B
1190 #   Commit E: merge B&C, resolving in favor of C
1191 #
1192 # This is an obvious add/add conflict for the submodule 'repo'.  Can
1193 # git detect it?
1194
1195 test_expect_success 'setup submodule add/add' '
1196         test_create_repo submodule-add-add &&
1197         (
1198                 cd submodule-add-add &&
1199
1200                 test_create_repo submod &&
1201                 (
1202                         cd submod &&
1203                         touch file-A &&
1204                         git add file-A &&
1205                         git commit -m A &&
1206                         git tag A &&
1207
1208                         git checkout -b B A &&
1209                         touch file-B &&
1210                         git add file-B &&
1211                         git commit -m B &&
1212                         git tag B &&
1213
1214                         git checkout -b C A &&
1215                         touch file-C &&
1216                         git add file-C &&
1217                         git commit -m C &&
1218                         git tag C
1219                 ) &&
1220
1221                 touch irrelevant-file &&
1222                 git add irrelevant-file &&
1223                 git commit -m A &&
1224                 git tag A &&
1225
1226                 git checkout -b B A &&
1227                 git -C submod reset --hard B &&
1228                 git add submod &&
1229                 git commit -m B &&
1230
1231                 git checkout -b C A &&
1232                 git -C submod reset --hard C &&
1233                 git add submod &&
1234                 git commit -m C &&
1235
1236                 git checkout -q B^0 &&
1237                 git merge -s ours -m D C^0 &&
1238                 git tag D &&
1239
1240                 git checkout -q C^0 &&
1241                 git merge -s ours -m E B^0 &&
1242                 git tag E
1243         )
1244 '
1245
1246 test_expect_failure 'check submodule add/add' '
1247         (
1248                 cd submodule-add-add &&
1249
1250                 git checkout D^0 &&
1251
1252                 test_must_fail git merge -s recursive E^0 &&
1253
1254                 git ls-files -s >out &&
1255                 test_line_count = 3 out &&
1256                 git ls-files -u >out &&
1257                 test_line_count = 2 out &&
1258                 git ls-files -o >out &&
1259                 test_line_count = 1 out
1260         )
1261 '
1262
1263 #
1264 # criss-cross with conflicting entry types:
1265 #
1266 #      B   D
1267 #      o---o
1268 #     / \ / \
1269 #  A o   X   ? F
1270 #     \ / \ /
1271 #      o---o
1272 #      C   E
1273 #
1274 #   Commit A: nothing of note
1275 #   Commit B: introduce submodule 'path'
1276 #   Commit C: introduce symlink 'path'
1277 #   Commit D: merge B&C, resolving in favor of B
1278 #   Commit E: merge B&C, resolving in favor of C
1279 #
1280 # This is an obvious add/add conflict for 'path'.  Can git detect it?
1281
1282 test_expect_success 'setup conflicting entry types (submodule vs symlink)' '
1283         test_create_repo submodule-symlink-add-add &&
1284         (
1285                 cd submodule-symlink-add-add &&
1286
1287                 test_create_repo path &&
1288                 (
1289                         cd path &&
1290                         touch file-B &&
1291                         git add file-B &&
1292                         git commit -m B &&
1293                         git tag B
1294                 ) &&
1295
1296                 touch irrelevant-file &&
1297                 git add irrelevant-file &&
1298                 git commit -m A &&
1299                 git tag A &&
1300
1301                 git checkout -b B A &&
1302                 git -C path reset --hard B &&
1303                 git add path &&
1304                 git commit -m B &&
1305
1306                 git checkout -b C A &&
1307                 rm -rf path/ &&
1308                 test_ln_s_add irrelevant-file path &&
1309                 git commit -m C &&
1310
1311                 git checkout -q B^0 &&
1312                 git merge -s ours -m D C^0 &&
1313                 git tag D &&
1314
1315                 git checkout -q C^0 &&
1316                 git merge -s ours -m E B^0 &&
1317                 git tag E
1318         )
1319 '
1320
1321 test_expect_failure 'check conflicting entry types (submodule vs symlink)' '
1322         (
1323                 cd submodule-symlink-add-add &&
1324
1325                 git checkout D^0 &&
1326
1327                 test_must_fail git merge -s recursive E^0 &&
1328
1329                 git ls-files -s >out &&
1330                 test_line_count = 3 out &&
1331                 git ls-files -u >out &&
1332                 test_line_count = 2 out &&
1333                 git ls-files -o >out &&
1334                 test_line_count = 1 out
1335         )
1336 '
1337
1338 #
1339 # criss-cross with regular files that have conflicting modes:
1340 #
1341 #      B   D
1342 #      o---o
1343 #     / \ / \
1344 #  A o   X   ? F
1345 #     \ / \ /
1346 #      o---o
1347 #      C   E
1348 #
1349 #   Commit A: nothing of note
1350 #   Commit B: introduce file source_me.bash, not executable
1351 #   Commit C: introduce file source_me.bash, executable
1352 #   Commit D: merge B&C, resolving in favor of B
1353 #   Commit E: merge B&C, resolving in favor of C
1354 #
1355 # This is an obvious add/add mode conflict.  Can git detect it?
1356
1357 test_expect_success 'setup conflicting modes for regular file' '
1358         test_create_repo regular-file-mode-conflict &&
1359         (
1360                 cd regular-file-mode-conflict &&
1361
1362                 touch irrelevant-file &&
1363                 git add irrelevant-file &&
1364                 git commit -m A &&
1365                 git tag A &&
1366
1367                 git checkout -b B A &&
1368                 echo "command_to_run" >source_me.bash &&
1369                 git add source_me.bash &&
1370                 git commit -m B &&
1371
1372                 git checkout -b C A &&
1373                 echo "command_to_run" >source_me.bash &&
1374                 git add source_me.bash &&
1375                 test_chmod +x source_me.bash &&
1376                 git commit -m C &&
1377
1378                 git checkout -q B^0 &&
1379                 git merge -s ours -m D C^0 &&
1380                 git tag D &&
1381
1382                 git checkout -q C^0 &&
1383                 git merge -s ours -m E B^0 &&
1384                 git tag E
1385         )
1386 '
1387
1388 test_expect_failure 'check conflicting modes for regular file' '
1389         (
1390                 cd regular-file-mode-conflict &&
1391
1392                 git checkout D^0 &&
1393
1394                 test_must_fail git merge -s recursive E^0 &&
1395
1396                 git ls-files -s >out &&
1397                 test_line_count = 3 out &&
1398                 git ls-files -u >out &&
1399                 test_line_count = 2 out &&
1400                 git ls-files -o >out &&
1401                 test_line_count = 1 out
1402         )
1403 '
1404
1405 test_done