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