t/test-lib-functions.sh

   1 # Library of functions shared by all tests scripts, included by
   2 # test-lib.sh.
   3 #
   4 # Copyright (c) 2005 Junio C Hamano
   5 #
   6 # This program is free software: you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation, either version 2 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see http://www.gnu.org/licenses/ .
  18
  19 # The semantics of the editor variables are that of invoking
  20 # sh -c "$EDITOR \"$@\"" files ...
  21 #
  22 # If our trash directory contains shell metacharacters, they will be
  23 # interpreted if we just set $EDITOR directly, so do a little dance with
  24 # environment variables to work around this.
  25 #
  26 # In particular, quoting isn't enough, as the path may contain the same quote
  27 # that we're using.
  28 test_set_editor () {
  29         FAKE_EDITOR="$1"
  30         export FAKE_EDITOR
  31         EDITOR='"$FAKE_EDITOR"'
  32         export EDITOR
  33 }
  34
  35 test_set_index_version () {
  36     GIT_INDEX_VERSION="$1"
  37     export GIT_INDEX_VERSION
  38 }
  39
  40 test_decode_color () {
  41         awk '
  42                 function name(n) {
  43                         if (n == 0) return "RESET";
  44                         if (n == 1) return "BOLD";
  45                         if (n == 30) return "BLACK";
  46                         if (n == 31) return "RED";
  47                         if (n == 32) return "GREEN";
  48                         if (n == 33) return "YELLOW";
  49                         if (n == 34) return "BLUE";
  50                         if (n == 35) return "MAGENTA";
  51                         if (n == 36) return "CYAN";
  52                         if (n == 37) return "WHITE";
  53                         if (n == 40) return "BLACK";
  54                         if (n == 41) return "BRED";
  55                         if (n == 42) return "BGREEN";
  56                         if (n == 43) return "BYELLOW";
  57                         if (n == 44) return "BBLUE";
  58                         if (n == 45) return "BMAGENTA";
  59                         if (n == 46) return "BCYAN";
  60                         if (n == 47) return "BWHITE";
  61                 }
  62                 {
  63                         while (match($0, /\033\[[0-9;]*m/) != 0) {
  64                                 printf "%s<", substr($0, 1, RSTART-1);
  65                                 codes = substr($0, RSTART+2, RLENGTH-3);
  66                                 if (length(codes) == 0)
  67                                         printf "%s", name(0)
  68                                 else {
  69                                         n = split(codes, ary, ";");
  70                                         sep = "";
  71                                         for (i = 1; i <= n; i++) {
  72                                                 printf "%s%s", sep, name(ary[i]);
  73                                                 sep = ";"
  74                                         }
  75                                 }
  76                                 printf ">";
  77                                 $0 = substr($0, RSTART + RLENGTH, length($0) - RSTART - RLENGTH + 1);
  78                         }
  79                         print
  80                 }
  81         '
  82 }
  83
  84 nul_to_q () {
  85         perl -pe 'y/\000/Q/'
  86 }
  87
  88 q_to_nul () {
  89         perl -pe 'y/Q/\000/'
  90 }
  91
  92 q_to_cr () {
  93         tr Q '\015'
  94 }
  95
  96 cr_to_q () {
  97         tr '\015' Q
  98 }
  99
 100 q_to_tab () {
 101         tr Q '\011'
 102 }
 103
 104 qz_to_tab_space () {
 105         tr QZ '\011\040'
 106 }
 107
 108 append_cr () {
 109         sed -e 's/$/Q/' | tr Q '\015'
 110 }
 111
 112 remove_cr () {
 113         tr '\015' Q | sed -e 's/Q$//'
 114 }
 115
 116 # In some bourne shell implementations, the "unset" builtin returns
 117 # nonzero status when a variable to be unset was not set in the first
 118 # place.
 119 #
 120 # Use sane_unset when that should not be considered an error.
 121
 122 sane_unset () {
 123         unset "$@"
 124         return 0
 125 }
 126
 127 test_tick () {
 128         if test -z "${test_tick+set}"
 129         then
 130                 test_tick=1112911993
 131         else
 132                 test_tick=$(($test_tick + 60))
 133         fi
 134         GIT_COMMITTER_DATE="$test_tick -0700"
 135         GIT_AUTHOR_DATE="$test_tick -0700"
 136         export GIT_COMMITTER_DATE GIT_AUTHOR_DATE
 137 }
 138
 139 # Stop execution and start a shell. This is useful for debugging tests and
 140 # only makes sense together with "-v".
 141 #
 142 # Be sure to remove all invocations of this command before submitting.
 143
 144 test_pause () {
 145         if test "$verbose" = t; then
 146                 "$SHELL_PATH" <&6 >&3 2>&4
 147         else
 148                 error >&5 "test_pause requires --verbose"
 149         fi
 150 }
 151
 152 # Wrap git in gdb. Adding this to a command can make it easier to
 153 # understand what is going on in a failing test.
 154 #
 155 # Example: "debug git checkout master".
 156 debug () {
 157          GIT_TEST_GDB=1 "$@"
 158 }
 159
 160 # Call test_commit with the arguments "<message> [<file> [<contents> [<tag>]]]"
 161 #
 162 # This will commit a file with the given contents and the given commit
 163 # message, and tag the resulting commit with the given tag name.
 164 #
 165 # <file>, <contents>, and <tag> all default to <message>.
 166
 167 test_commit () {
 168         notick= &&
 169         signoff= &&
 170         while test $# != 0
 171         do
 172                 case "$1" in
 173                 --notick)
 174                         notick=yes
 175                         ;;
 176                 --signoff)
 177                         signoff="$1"
 178                         ;;
 179                 *)
 180                         break
 181                         ;;
 182                 esac
 183                 shift
 184         done &&
 185         file=${2:-"$1.t"} &&
 186         echo "${3-$1}" > "$file" &&
 187         git add "$file" &&
 188         if test -z "$notick"
 189         then
 190                 test_tick
 191         fi &&
 192         git commit $signoff -m "$1" &&
 193         git tag "${4:-$1}"
 194 }
 195
 196 # Call test_merge with the arguments "<message> <commit>", where <commit>
 197 # can be a tag pointing to the commit-to-merge.
 198
 199 test_merge () {
 200         test_tick &&
 201         git merge -m "$1" "$2" &&
 202         git tag "$1"
 203 }
 204
 205 # This function helps systems where core.filemode=false is set.
 206 # Use it instead of plain 'chmod +x' to set or unset the executable bit
 207 # of a file in the working directory and add it to the index.
 208
 209 test_chmod () {
 210         chmod "$@" &&
 211         git update-index --add "--chmod=$@"
 212 }
 213
 214 # Unset a configuration variable, but don't fail if it doesn't exist.
 215 test_unconfig () {
 216         config_dir=
 217         if test "$1" = -C
 218         then
 219                 shift
 220                 config_dir=$1
 221                 shift
 222         fi
 223         git ${config_dir:+-C "$config_dir"} config --unset-all "$@"
 224         config_status=$?
 225         case "$config_status" in
 226         5) # ok, nothing to unset
 227                 config_status=0
 228                 ;;
 229         esac
 230         return $config_status
 231 }
 232
 233 # Set git config, automatically unsetting it after the test is over.
 234 test_config () {
 235         config_dir=
 236         if test "$1" = -C
 237         then
 238                 shift
 239                 config_dir=$1
 240                 shift
 241         fi
 242         test_when_finished "test_unconfig ${config_dir:+-C '$config_dir'} '$1'" &&
 243         git ${config_dir:+-C "$config_dir"} config "$@"
 244 }
 245
 246 test_config_global () {
 247         test_when_finished "test_unconfig --global '$1'" &&
 248         git config --global "$@"
 249 }
 250
 251 write_script () {
 252         {
 253                 echo "#!${2-"$SHELL_PATH"}" &&
 254                 cat
 255         } >"$1" &&
 256         chmod +x "$1"
 257 }
 258
 259 # Use test_set_prereq to tell that a particular prerequisite is available.
 260 # The prerequisite can later be checked for in two ways:
 261 #
 262 # - Explicitly using test_have_prereq.
 263 #
 264 # - Implicitly by specifying the prerequisite tag in the calls to
 265 #   test_expect_{success,failure,code}.
 266 #
 267 # The single parameter is the prerequisite tag (a simple word, in all
 268 # capital letters by convention).
 269
 270 test_set_prereq () {
 271         satisfied_prereq="$satisfied_prereq$1 "
 272 }
 273 satisfied_prereq=" "
 274 lazily_testable_prereq= lazily_tested_prereq=
 275
 276 # Usage: test_lazy_prereq PREREQ 'script'
 277 test_lazy_prereq () {
 278         lazily_testable_prereq="$lazily_testable_prereq$1 "
 279         eval test_prereq_lazily_$1=\$2
 280 }
 281
 282 test_run_lazy_prereq_ () {
 283         script='
 284 mkdir -p "$TRASH_DIRECTORY/prereq-test-dir" &&
 285 (
 286         cd "$TRASH_DIRECTORY/prereq-test-dir" &&'"$2"'
 287 )'
 288         say >&3 "checking prerequisite: $1"
 289         say >&3 "$script"
 290         test_eval_ "$script"
 291         eval_ret=$?
 292         rm -rf "$TRASH_DIRECTORY/prereq-test-dir"
 293         if test "$eval_ret" = 0; then
 294                 say >&3 "prerequisite $1 ok"
 295         else
 296                 say >&3 "prerequisite $1 not satisfied"
 297         fi
 298         return $eval_ret
 299 }
 300
 301 test_have_prereq () {
 302         # prerequisites can be concatenated with ','
 303         save_IFS=$IFS
 304         IFS=,
 305         set -- $*
 306         IFS=$save_IFS
 307
 308         total_prereq=0
 309         ok_prereq=0
 310         missing_prereq=
 311
 312         for prerequisite
 313         do
 314                 case "$prerequisite" in
 315                 !*)
 316                         negative_prereq=t
 317                         prerequisite=${prerequisite#!}
 318                         ;;
 319                 *)
 320                         negative_prereq=
 321                 esac
 322
 323                 case " $lazily_tested_prereq " in
 324                 *" $prerequisite "*)
 325                         ;;
 326                 *)
 327                         case " $lazily_testable_prereq " in
 328                         *" $prerequisite "*)
 329                                 eval "script=\$test_prereq_lazily_$prerequisite" &&
 330                                 if test_run_lazy_prereq_ "$prerequisite" "$script"
 331                                 then
 332                                         test_set_prereq $prerequisite
 333                                 fi
 334                                 lazily_tested_prereq="$lazily_tested_prereq$prerequisite "
 335                         esac
 336                         ;;
 337                 esac
 338
 339                 total_prereq=$(($total_prereq + 1))
 340                 case "$satisfied_prereq" in
 341                 *" $prerequisite "*)
 342                         satisfied_this_prereq=t
 343                         ;;
 344                 *)
 345                         satisfied_this_prereq=
 346                 esac
 347
 348                 case "$satisfied_this_prereq,$negative_prereq" in
 349                 t,|,t)
 350                         ok_prereq=$(($ok_prereq + 1))
 351                         ;;
 352                 *)
 353                         # Keep a list of missing prerequisites; restore
 354                         # the negative marker if necessary.
 355                         prerequisite=${negative_prereq:+!}$prerequisite
 356                         if test -z "$missing_prereq"
 357                         then
 358                                 missing_prereq=$prerequisite
 359                         else
 360                                 missing_prereq="$prerequisite,$missing_prereq"
 361                         fi
 362                 esac
 363         done
 364
 365         test $total_prereq = $ok_prereq
 366 }
 367
 368 test_declared_prereq () {
 369         case ",$test_prereq," in
 370         *,$1,*)
 371                 return 0
 372                 ;;
 373         esac
 374         return 1
 375 }
 376
 377 test_verify_prereq () {
 378         test -z "$test_prereq" ||
 379         expr >/dev/null "$test_prereq" : '[A-Z0-9_,!]*$' ||
 380         error "bug in the test script: '$test_prereq' does not look like a prereq"
 381 }
 382
 383 test_expect_failure () {
 384         test_start_
 385         test "$#" = 3 && { test_prereq=$1; shift; } || test_prereq=
 386         test "$#" = 2 ||
 387         error "bug in the test script: not 2 or 3 parameters to test-expect-failure"
 388         test_verify_prereq
 389         export test_prereq
 390         if ! test_skip "$@"
 391         then
 392                 say >&3 "checking known breakage: $2"
 393                 if test_run_ "$2" expecting_failure
 394                 then
 395                         test_known_broken_ok_ "$1"
 396                 else
 397                         test_known_broken_failure_ "$1"
 398                 fi
 399         fi
 400         test_finish_
 401 }
 402
 403 test_expect_success () {
 404         test_start_
 405         test "$#" = 3 && { test_prereq=$1; shift; } || test_prereq=
 406         test "$#" = 2 ||
 407         error "bug in the test script: not 2 or 3 parameters to test-expect-success"
 408         test_verify_prereq
 409         export test_prereq
 410         if ! test_skip "$@"
 411         then
 412                 say >&3 "expecting success: $2"
 413                 if test_run_ "$2"
 414                 then
 415                         test_ok_ "$1"
 416                 else
 417                         test_failure_ "$@"
 418                 fi
 419         fi
 420         test_finish_
 421 }
 422
 423 # test_external runs external test scripts that provide continuous
 424 # test output about their progress, and succeeds/fails on
 425 # zero/non-zero exit code.  It outputs the test output on stdout even
 426 # in non-verbose mode, and announces the external script with "# run
 427 # <n>: ..." before running it.  When providing relative paths, keep in
 428 # mind that all scripts run in "trash directory".
 429 # Usage: test_external description command arguments...
 430 # Example: test_external 'Perl API' perl ../path/to/test.pl
 431 test_external () {
 432         test "$#" = 4 && { test_prereq=$1; shift; } || test_prereq=
 433         test "$#" = 3 ||
 434         error >&5 "bug in the test script: not 3 or 4 parameters to test_external"
 435         descr="$1"
 436         shift
 437         test_verify_prereq
 438         export test_prereq
 439         if ! test_skip "$descr" "$@"
 440         then
 441                 # Announce the script to reduce confusion about the
 442                 # test output that follows.
 443                 say_color "" "# run $test_count: $descr ($*)"
 444                 # Export TEST_DIRECTORY, TRASH_DIRECTORY and GIT_TEST_LONG
 445                 # to be able to use them in script
 446                 export TEST_DIRECTORY TRASH_DIRECTORY GIT_TEST_LONG
 447                 # Run command; redirect its stderr to &4 as in
 448                 # test_run_, but keep its stdout on our stdout even in
 449                 # non-verbose mode.
 450                 "$@" 2>&4
 451                 if test "$?" = 0
 452                 then
 453                         if test $test_external_has_tap -eq 0; then
 454                                 test_ok_ "$descr"
 455                         else
 456                                 say_color "" "# test_external test $descr was ok"
 457                                 test_success=$(($test_success + 1))
 458                         fi
 459                 else
 460                         if test $test_external_has_tap -eq 0; then
 461                                 test_failure_ "$descr" "$@"
 462                         else
 463                                 say_color error "# test_external test $descr failed: $@"
 464                                 test_failure=$(($test_failure + 1))
 465                         fi
 466                 fi
 467         fi
 468 }
 469
 470 # Like test_external, but in addition tests that the command generated
 471 # no output on stderr.
 472 test_external_without_stderr () {
 473         # The temporary file has no (and must have no) security
 474         # implications.
 475         tmp=${TMPDIR:-/tmp}
 476         stderr="$tmp/git-external-stderr.$$.tmp"
 477         test_external "$@" 4> "$stderr"
 478         test -f "$stderr" || error "Internal error: $stderr disappeared."
 479         descr="no stderr: $1"
 480         shift
 481         say >&3 "# expecting no stderr from previous command"
 482         if test ! -s "$stderr"
 483         then
 484                 rm "$stderr"
 485
 486                 if test $test_external_has_tap -eq 0; then
 487                         test_ok_ "$descr"
 488                 else
 489                         say_color "" "# test_external_without_stderr test $descr was ok"
 490                         test_success=$(($test_success + 1))
 491                 fi
 492         else
 493                 if test "$verbose" = t
 494                 then
 495                         output=$(echo; echo "# Stderr is:"; cat "$stderr")
 496                 else
 497                         output=
 498                 fi
 499                 # rm first in case test_failure exits.
 500                 rm "$stderr"
 501                 if test $test_external_has_tap -eq 0; then
 502                         test_failure_ "$descr" "$@" "$output"
 503                 else
 504                         say_color error "# test_external_without_stderr test $descr failed: $@: $output"
 505                         test_failure=$(($test_failure + 1))
 506                 fi
 507         fi
 508 }
 509
 510 # debugging-friendly alternatives to "test [-f|-d|-e]"
 511 # The commands test the existence or non-existence of $1. $2 can be
 512 # given to provide a more precise diagnosis.
 513 test_path_is_file () {
 514         if ! test -f "$1"
 515         then
 516                 echo "File $1 doesn't exist. $2"
 517                 false
 518         fi
 519 }
 520
 521 test_path_is_dir () {
 522         if ! test -d "$1"
 523         then
 524                 echo "Directory $1 doesn't exist. $2"
 525                 false
 526         fi
 527 }
 528
 529 # Check if the directory exists and is empty as expected, barf otherwise.
 530 test_dir_is_empty () {
 531         test_path_is_dir "$1" &&
 532         if test -n "$(ls -a1 "$1" | egrep -v '^\.\.?$')"
 533         then
 534                 echo "Directory '$1' is not empty, it contains:"
 535                 ls -la "$1"
 536                 return 1
 537         fi
 538 }
 539
 540 test_path_is_missing () {
 541         if test -e "$1"
 542         then
 543                 echo "Path exists:"
 544                 ls -ld "$1"
 545                 if test $# -ge 1
 546                 then
 547                         echo "$*"
 548                 fi
 549                 false
 550         fi
 551 }
 552
 553 # test_line_count checks that a file has the number of lines it
 554 # ought to. For example:
 555 #
 556 #       test_expect_success 'produce exactly one line of output' '
 557 #               do something >output &&
 558 #               test_line_count = 1 output
 559 #       '
 560 #
 561 # is like "test $(wc -l <output) = 1" except that it passes the
 562 # output through when the number of lines is wrong.
 563
 564 test_line_count () {
 565         if test $# != 3
 566         then
 567                 error "bug in the test script: not 3 parameters to test_line_count"
 568         elif ! test $(wc -l <"$3") "$1" "$2"
 569         then
 570                 echo "test_line_count: line count for $3 !$1 $2"
 571                 cat "$3"
 572                 return 1
 573         fi
 574 }
 575
 576 # This is not among top-level (test_expect_success | test_expect_failure)
 577 # but is a prefix that can be used in the test script, like:
 578 #
 579 #       test_expect_success 'complain and die' '
 580 #           do something &&
 581 #           do something else &&
 582 #           test_must_fail git checkout ../outerspace
 583 #       '
 584 #
 585 # Writing this as "! git checkout ../outerspace" is wrong, because
 586 # the failure could be due to a segv.  We want a controlled failure.
 587
 588 test_must_fail () {
 589         "$@"
 590         exit_code=$?
 591         if test $exit_code = 0; then
 592                 echo >&2 "test_must_fail: command succeeded: $*"
 593                 return 1
 594         elif test $exit_code -gt 129 && test $exit_code -le 192; then
 595                 echo >&2 "test_must_fail: died by signal: $*"
 596                 return 1
 597         elif test $exit_code = 127; then
 598                 echo >&2 "test_must_fail: command not found: $*"
 599                 return 1
 600         elif test $exit_code = 126; then
 601                 echo >&2 "test_must_fail: valgrind error: $*"
 602                 return 1
 603         fi
 604         return 0
 605 }
 606
 607 # Similar to test_must_fail, but tolerates success, too.  This is
 608 # meant to be used in contexts like:
 609 #
 610 #       test_expect_success 'some command works without configuration' '
 611 #               test_might_fail git config --unset all.configuration &&
 612 #               do something
 613 #       '
 614 #
 615 # Writing "git config --unset all.configuration || :" would be wrong,
 616 # because we want to notice if it fails due to segv.
 617
 618 test_might_fail () {
 619         "$@"
 620         exit_code=$?
 621         if test $exit_code -gt 129 && test $exit_code -le 192; then
 622                 echo >&2 "test_might_fail: died by signal: $*"
 623                 return 1
 624         elif test $exit_code = 127; then
 625                 echo >&2 "test_might_fail: command not found: $*"
 626                 return 1
 627         fi
 628         return 0
 629 }
 630
 631 # Similar to test_must_fail and test_might_fail, but check that a
 632 # given command exited with a given exit code. Meant to be used as:
 633 #
 634 #       test_expect_success 'Merge with d/f conflicts' '
 635 #               test_expect_code 1 git merge "merge msg" B master
 636 #       '
 637
 638 test_expect_code () {
 639         want_code=$1
 640         shift
 641         "$@"
 642         exit_code=$?
 643         if test $exit_code = $want_code
 644         then
 645                 return 0
 646         fi
 647
 648         echo >&2 "test_expect_code: command exited with $exit_code, we wanted $want_code $*"
 649         return 1
 650 }
 651
 652 # test_cmp is a helper function to compare actual and expected output.
 653 # You can use it like:
 654 #
 655 #       test_expect_success 'foo works' '
 656 #               echo expected >expected &&
 657 #               foo >actual &&
 658 #               test_cmp expected actual
 659 #       '
 660 #
 661 # This could be written as either "cmp" or "diff -u", but:
 662 # - cmp's output is not nearly as easy to read as diff -u
 663 # - not all diff versions understand "-u"
 664
 665 test_cmp() {
 666         $GIT_TEST_CMP "$@"
 667 }
 668
 669 # test_cmp_bin - helper to compare binary files
 670
 671 test_cmp_bin() {
 672         cmp "$@"
 673 }
 674
 675 # Call any command "$@" but be more verbose about its
 676 # failure. This is handy for commands like "test" which do
 677 # not output anything when they fail.
 678 verbose () {
 679         "$@" && return 0
 680         echo >&2 "command failed: $(git rev-parse --sq-quote "$@")"
 681         return 1
 682 }
 683
 684 # Check if the file expected to be empty is indeed empty, and barfs
 685 # otherwise.
 686
 687 test_must_be_empty () {
 688         if test -s "$1"
 689         then
 690                 echo "'$1' is not empty, it contains:"
 691                 cat "$1"
 692                 return 1
 693         fi
 694 }
 695
 696 # Tests that its two parameters refer to the same revision
 697 test_cmp_rev () {
 698         git rev-parse --verify "$1" >expect.rev &&
 699         git rev-parse --verify "$2" >actual.rev &&
 700         test_cmp expect.rev actual.rev
 701 }
 702
 703 # Print a sequence of numbers or letters in increasing order.  This is
 704 # similar to GNU seq(1), but the latter might not be available
 705 # everywhere (and does not do letters).  It may be used like:
 706 #
 707 #       for i in $(test_seq 100)
 708 #       do
 709 #               for j in $(test_seq 10 20)
 710 #               do
 711 #                       for k in $(test_seq a z)
 712 #                       do
 713 #                               echo $i-$j-$k
 714 #                       done
 715 #               done
 716 #       done
 717
 718 test_seq () {
 719         case $# in
 720         1)      set 1 "$@" ;;
 721         2)      ;;
 722         *)      error "bug in the test script: not 1 or 2 parameters to test_seq" ;;
 723         esac
 724         perl -le 'print for $ARGV[0]..$ARGV[1]' -- "$@"
 725 }
 726
 727 # This function can be used to schedule some commands to be run
 728 # unconditionally at the end of the test to restore sanity:
 729 #
 730 #       test_expect_success 'test core.capslock' '
 731 #               git config core.capslock true &&
 732 #               test_when_finished "git config --unset core.capslock" &&
 733 #               hello world
 734 #       '
 735 #
 736 # That would be roughly equivalent to
 737 #
 738 #       test_expect_success 'test core.capslock' '
 739 #               git config core.capslock true &&
 740 #               hello world
 741 #               git config --unset core.capslock
 742 #       '
 743 #
 744 # except that the greeting and config --unset must both succeed for
 745 # the test to pass.
 746 #
 747 # Note that under --immediate mode, no clean-up is done to help diagnose
 748 # what went wrong.
 749
 750 test_when_finished () {
 751         # We cannot detect when we are in a subshell in general, but by
 752         # doing so on Bash is better than nothing (the test will
 753         # silently pass on other shells).
 754         test "${BASH_SUBSHELL-0}" = 0 ||
 755         error "bug in test script: test_when_finished does nothing in a subshell"
 756         test_cleanup="{ $*
 757                 } && (exit \"\$eval_ret\"); eval_ret=\$?; $test_cleanup"
 758 }
 759
 760 # Most tests can use the created repository, but some may need to create more.
 761 # Usage: test_create_repo <directory>
 762 test_create_repo () {
 763         test "$#" = 1 ||
 764         error "bug in the test script: not 1 parameter to test-create-repo"
 765         repo="$1"
 766         mkdir -p "$repo"
 767         (
 768                 cd "$repo" || error "Cannot setup test environment"
 769                 "$GIT_EXEC_PATH/git-init" "--template=$GIT_BUILD_DIR/templates/blt/" >&3 2>&4 ||
 770                 error "cannot run git init -- have you built things yet?"
 771                 mv .git/hooks .git/hooks-disabled
 772         ) || exit
 773 }
 774
 775 # This function helps on symlink challenged file systems when it is not
 776 # important that the file system entry is a symbolic link.
 777 # Use test_ln_s_add instead of "ln -s x y && git add y" to add a
 778 # symbolic link entry y to the index.
 779
 780 test_ln_s_add () {
 781         if test_have_prereq SYMLINKS
 782         then
 783                 ln -s "$1" "$2" &&
 784                 git update-index --add "$2"
 785         else
 786                 printf '%s' "$1" >"$2" &&
 787                 ln_s_obj=$(git hash-object -w "$2") &&
 788                 git update-index --add --cacheinfo 120000 $ln_s_obj "$2" &&
 789                 # pick up stat info from the file
 790                 git update-index "$2"
 791         fi
 792 }
 793
 794 # This function writes out its parameters, one per line
 795 test_write_lines () {
 796         printf "%s\n" "$@"
 797 }
 798
 799 perl () {
 800         command "$PERL_PATH" "$@"
 801 }
 802
 803 # Is the value one of the various ways to spell a boolean true/false?
 804 test_normalize_bool () {
 805         git -c magic.variable="$1" config --bool magic.variable 2>/dev/null
 806 }
 807
 808 # Given a variable $1, normalize the value of it to one of "true",
 809 # "false", or "auto" and store the result to it.
 810 #
 811 #     test_tristate GIT_TEST_HTTPD
 812 #
 813 # A variable set to an empty string is set to 'false'.
 814 # A variable set to 'false' or 'auto' keeps its value.
 815 # Anything else is set to 'true'.
 816 # An unset variable defaults to 'auto'.
 817 #
 818 # The last rule is to allow people to set the variable to an empty
 819 # string and export it to decline testing the particular feature
 820 # for versions both before and after this change.  We used to treat
 821 # both unset and empty variable as a signal for "do not test" and
 822 # took any non-empty string as "please test".
 823
 824 test_tristate () {
 825         if eval "test x\"\${$1+isset}\" = xisset"
 826         then
 827                 # explicitly set
 828                 eval "
 829                         case \"\$$1\" in
 830                         '')     $1=false ;;
 831                         auto)   ;;
 832                         *)      $1=\$(test_normalize_bool \$$1 || echo true) ;;
 833                         esac
 834                 "
 835         else
 836                 eval "$1=auto"
 837         fi
 838 }
 839
 840 # Exit the test suite, either by skipping all remaining tests or by
 841 # exiting with an error. If "$1" is "auto", we then we assume we were
 842 # opportunistically trying to set up some tests and we skip. If it is
 843 # "true", then we report a failure.
 844 #
 845 # The error/skip message should be given by $2.
 846 #
 847 test_skip_or_die () {
 848         case "$1" in
 849         auto)
 850                 skip_all=$2
 851                 test_done
 852                 ;;
 853         true)
 854                 error "$2"
 855                 ;;
 856         *)
 857                 error "BUG: test tristate is '$1' (real error: $2)"
 858         esac
 859 }
 860
 861 # Overwrite bytes at an offset in a file
 862 # $1 ... the file to modify
 863 # $2 ... byte offset into file
 864 # stdin ... new bytes
 865 test_overwrite_bytes () {
 866         perl -e '
 867                 $fname = shift @ARGV;
 868                 $offset = shift @ARGV;
 869                 $bytes = <>;
 870                 open my $fh, "+<", $fname       or die "open $fname: $!\n";
 871                 seek($fh, $offset, 0)           or die "seek $fname: $!\n";
 872                 syswrite($fh, $bytes)           or die "write $fname: $!\n";
 873                 close $fh                       or die "close $fname: $!\n";
 874         ' "$@"
 875 }
 876
 877 # The following mingw_* functions obey POSIX shell syntax, but are actually
 878 # bash scripts, and are meant to be used only with bash on Windows.
 879
 880 # A test_cmp function that treats LF and CRLF equal and avoids to fork
 881 # diff when possible.
 882 mingw_test_cmp () {
 883         # Read text into shell variables and compare them. If the results
 884         # are different, use regular diff to report the difference.
 885         local test_cmp_a= test_cmp_b=
 886
 887         # When text came from stdin (one argument is '-') we must feed it
 888         # to diff.
 889         local stdin_for_diff=
 890
 891         # Since it is difficult to detect the difference between an
 892         # empty input file and a failure to read the files, we go straight
 893         # to diff if one of the inputs is empty.
 894         if test -s "$1" && test -s "$2"
 895         then
 896                 # regular case: both files non-empty
 897                 mingw_read_file_strip_cr_ test_cmp_a <"$1"
 898                 mingw_read_file_strip_cr_ test_cmp_b <"$2"
 899         elif test -s "$1" && test "$2" = -
 900         then
 901                 # read 2nd file from stdin
 902                 mingw_read_file_strip_cr_ test_cmp_a <"$1"
 903                 mingw_read_file_strip_cr_ test_cmp_b
 904                 stdin_for_diff='<<<"$test_cmp_b"'
 905         elif test "$1" = - && test -s "$2"
 906         then
 907                 # read 1st file from stdin
 908                 mingw_read_file_strip_cr_ test_cmp_a
 909                 mingw_read_file_strip_cr_ test_cmp_b <"$2"
 910                 stdin_for_diff='<<<"$test_cmp_a"'
 911         fi
 912         test -n "$test_cmp_a" &&
 913         test -n "$test_cmp_b" &&
 914         test "$test_cmp_a" = "$test_cmp_b" ||
 915         eval "diff -u \"\$@\" $stdin_for_diff"
 916 }
 917
 918 # $1 is the name of the shell variable to fill in
 919 mingw_read_file_strip_cr_ () {
 920         # Read line-wise using LF as the line separator
 921         # and use IFS to strip CR.
 922         local line
 923         while :
 924         do
 925                 if IFS=$'\r' read -r -d $'\n' line
 926                 then
 927                         # good
 928                         line=$line$'\n'
 929                 else
 930                         # we get here at EOF, but also if the last line
 931                         # was not terminated by LF; in the latter case,
 932                         # some text was read
 933                         if test -z "$line"
 934                         then
 935                                 # EOF, really
 936                                 break
 937                         fi
 938                 fi
 939                 eval "$1=\$$1\$line"
 940         done
 941 }