summaryrefslogtreecommitdiff
path: root/t/test-lib-functions.sh
blob: b7957b87bb9602748d6f84eeaaeb3c6820b1142e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
# Library of functions shared by all tests scripts, included by
# test-lib.sh.
#
# Copyright (c) 2005 Junio C Hamano
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see http://www.gnu.org/licenses/ .

# The semantics of the editor variables are that of invoking
# sh -c "$EDITOR \"$@\"" files ...
#
# If our trash directory contains shell metacharacters, they will be
# interpreted if we just set $EDITOR directly, so do a little dance with
# environment variables to work around this.
#
# In particular, quoting isn't enough, as the path may contain the same quote
# that we're using.
test_set_editor () {
	FAKE_EDITOR="$1"
	export FAKE_EDITOR
	EDITOR='"$FAKE_EDITOR"'
	export EDITOR
}

test_set_index_version () {
    GIT_INDEX_VERSION="$1"
    export GIT_INDEX_VERSION
}

test_decode_color () {
	awk '
		function name(n) {
			if (n == 0) return "RESET";
			if (n == 1) return "BOLD";
			if (n == 30) return "BLACK";
			if (n == 31) return "RED";
			if (n == 32) return "GREEN";
			if (n == 33) return "YELLOW";
			if (n == 34) return "BLUE";
			if (n == 35) return "MAGENTA";
			if (n == 36) return "CYAN";
			if (n == 37) return "WHITE";
			if (n == 40) return "BLACK";
			if (n == 41) return "BRED";
			if (n == 42) return "BGREEN";
			if (n == 43) return "BYELLOW";
			if (n == 44) return "BBLUE";
			if (n == 45) return "BMAGENTA";
			if (n == 46) return "BCYAN";
			if (n == 47) return "BWHITE";
		}
		{
			while (match($0, /\033\[[0-9;]*m/) != 0) {
				printf "%s<", substr($0, 1, RSTART-1);
				codes = substr($0, RSTART+2, RLENGTH-3);
				if (length(codes) == 0)
					printf "%s", name(0)
				else {
					n = split(codes, ary, ";");
					sep = "";
					for (i = 1; i <= n; i++) {
						printf "%s%s", sep, name(ary[i]);
						sep = ";"
					}
				}
				printf ">";
				$0 = substr($0, RSTART + RLENGTH, length($0) - RSTART - RLENGTH + 1);
			}
			print
		}
	'
}

nul_to_q () {
	perl -pe 'y/\000/Q/'
}

q_to_nul () {
	perl -pe 'y/Q/\000/'
}

q_to_cr () {
	tr Q '\015'
}

q_to_tab () {
	tr Q '\011'
}

qz_to_tab_space () {
	tr QZ '\011\040'
}

append_cr () {
	sed -e 's/$/Q/' | tr Q '\015'
}

remove_cr () {
	tr '\015' Q | sed -e 's/Q$//'
}

# In some bourne shell implementations, the "unset" builtin returns
# nonzero status when a variable to be unset was not set in the first
# place.
#
# Use sane_unset when that should not be considered an error.

sane_unset () {
	unset "$@"
	return 0
}

test_tick () {
	if test -z "${test_tick+set}"
	then
		test_tick=1112911993
	else
		test_tick=$(($test_tick + 60))
	fi
	GIT_COMMITTER_DATE="$test_tick -0700"
	GIT_AUTHOR_DATE="$test_tick -0700"
	export GIT_COMMITTER_DATE GIT_AUTHOR_DATE
}

# Stop execution and start a shell. This is useful for debugging tests and
# only makes sense together with "-v".
#
# Be sure to remove all invocations of this command before submitting.

test_pause () {
	if test "$verbose" = t; then
		"$SHELL_PATH" <&6 >&3 2>&4
	else
		error >&5 "test_pause requires --verbose"
	fi
}

# Call test_commit with the arguments "<message> [<file> [<contents> [<tag>]]]"
#
# This will commit a file with the given contents and the given commit
# message, and tag the resulting commit with the given tag name.
#
# <file>, <contents>, and <tag> all default to <message>.

test_commit () {
	notick= &&
	signoff= &&
	while test $# != 0
	do
		case "$1" in
		--notick)
			notick=yes
			;;
		--signoff)
			signoff="$1"
			;;
		*)
			break
			;;
		esac
		shift
	done &&
	file=${2:-"$1.t"} &&
	echo "${3-$1}" > "$file" &&
	git add "$file" &&
	if test -z "$notick"
	then
		test_tick
	fi &&
	git commit $signoff -m "$1" &&
	git tag "${4:-$1}"
}

# Call test_merge with the arguments "<message> <commit>", where <commit>
# can be a tag pointing to the commit-to-merge.

test_merge () {
	test_tick &&
	git merge -m "$1" "$2" &&
	git tag "$1"
}

# This function helps systems where core.filemode=false is set.
# Use it instead of plain 'chmod +x' to set or unset the executable bit
# of a file in the working directory and add it to the index.

test_chmod () {
	chmod "$@" &&
	git update-index --add "--chmod=$@"
}

# Unset a configuration variable, but don't fail if it doesn't exist.
test_unconfig () {
	git config --unset-all "$@"
	config_status=$?
	case "$config_status" in
	5) # ok, nothing to unset
		config_status=0
		;;
	esac
	return $config_status
}

# Set git config, automatically unsetting it after the test is over.
test_config () {
	test_when_finished "test_unconfig '$1'" &&
	git config "$@"
}

test_config_global () {
	test_when_finished "test_unconfig --global '$1'" &&
	git config --global "$@"
}

write_script () {
	{
		echo "#!${2-"$SHELL_PATH"}" &&
		cat
	} >"$1" &&
	chmod +x "$1"
}

# Use test_set_prereq to tell that a particular prerequisite is available.
# The prerequisite can later be checked for in two ways:
#
# - Explicitly using test_have_prereq.
#
# - Implicitly by specifying the prerequisite tag in the calls to
#   test_expect_{success,failure,code}.
#
# The single parameter is the prerequisite tag (a simple word, in all
# capital letters by convention).

test_set_prereq () {
	satisfied_prereq="$satisfied_prereq$1 "
}
satisfied_prereq=" "
lazily_testable_prereq= lazily_tested_prereq=

# Usage: test_lazy_prereq PREREQ 'script'
test_lazy_prereq () {
	lazily_testable_prereq="$lazily_testable_prereq$1 "
	eval test_prereq_lazily_$1=\$2
}

test_run_lazy_prereq_ () {
	script='
mkdir -p "$TRASH_DIRECTORY/prereq-test-dir" &&
(
	cd "$TRASH_DIRECTORY/prereq-test-dir" &&'"$2"'
)'
	say >&3 "checking prerequisite: $1"
	say >&3 "$script"
	test_eval_ "$script"
	eval_ret=$?
	rm -rf "$TRASH_DIRECTORY/prereq-test-dir"
	if test "$eval_ret" = 0; then
		say >&3 "prerequisite $1 ok"
	else
		say >&3 "prerequisite $1 not satisfied"
	fi
	return $eval_ret
}

test_have_prereq () {
	# prerequisites can be concatenated with ','
	save_IFS=$IFS
	IFS=,
	set -- $*
	IFS=$save_IFS

	total_prereq=0
	ok_prereq=0
	missing_prereq=

	for prerequisite
	do
		case "$prerequisite" in
		!*)
			negative_prereq=t
			prerequisite=${prerequisite#!}
			;;
		*)
			negative_prereq=
		esac

		case " $lazily_tested_prereq " in
		*" $prerequisite "*)
			;;
		*)
			case " $lazily_testable_prereq " in
			*" $prerequisite "*)
				eval "script=\$test_prereq_lazily_$prerequisite" &&
				if test_run_lazy_prereq_ "$prerequisite" "$script"
				then
					test_set_prereq $prerequisite
				fi
				lazily_tested_prereq="$lazily_tested_prereq$prerequisite "
			esac
			;;
		esac

		total_prereq=$(($total_prereq + 1))
		case "$satisfied_prereq" in
		*" $prerequisite "*)
			satisfied_this_prereq=t
			;;
		*)
			satisfied_this_prereq=
		esac

		case "$satisfied_this_prereq,$negative_prereq" in
		t,|,t)
			ok_prereq=$(($ok_prereq + 1))
			;;
		*)
			# Keep a list of missing prerequisites; restore
			# the negative marker if necessary.
			prerequisite=${negative_prereq:+!}$prerequisite
			if test -z "$missing_prereq"
			then
				missing_prereq=$prerequisite
			else
				missing_prereq="$prerequisite,$missing_prereq"
			fi
		esac
	done

	test $total_prereq = $ok_prereq
}

test_declared_prereq () {
	case ",$test_prereq," in
	*,$1,*)
		return 0
		;;
	esac
	return 1
}

test_expect_failure () {
	test_start_
	test "$#" = 3 && { test_prereq=$1; shift; } || test_prereq=
	test "$#" = 2 ||
	error "bug in the test script: not 2 or 3 parameters to test-expect-failure"
	export test_prereq
	if ! test_skip "$@"
	then
		say >&3 "checking known breakage: $2"
		if test_run_ "$2" expecting_failure
		then
			test_known_broken_ok_ "$1"
		else
			test_known_broken_failure_ "$1"
		fi
	fi
	test_finish_
}

test_expect_success () {
	test_start_
	test "$#" = 3 && { test_prereq=$1; shift; } || test_prereq=
	test "$#" = 2 ||
	error "bug in the test script: not 2 or 3 parameters to test-expect-success"
	export test_prereq
	if ! test_skip "$@"
	then
		say >&3 "expecting success: $2"
		if test_run_ "$2"
		then
			test_ok_ "$1"
		else
			test_failure_ "$@"
		fi
	fi
	test_finish_
}

# test_external runs external test scripts that provide continuous
# test output about their progress, and succeeds/fails on
# zero/non-zero exit code.  It outputs the test output on stdout even
# in non-verbose mode, and announces the external script with "# run
# <n>: ..." before running it.  When providing relative paths, keep in
# mind that all scripts run in "trash directory".
# Usage: test_external description command arguments...
# Example: test_external 'Perl API' perl ../path/to/test.pl
test_external () {
	test "$#" = 4 && { test_prereq=$1; shift; } || test_prereq=
	test "$#" = 3 ||
	error >&5 "bug in the test script: not 3 or 4 parameters to test_external"
	descr="$1"
	shift
	export test_prereq
	if ! test_skip "$descr" "$@"
	then
		# Announce the script to reduce confusion about the
		# test output that follows.
		say_color "" "# run $test_count: $descr ($*)"
		# Export TEST_DIRECTORY, TRASH_DIRECTORY and GIT_TEST_LONG
		# to be able to use them in script
		export TEST_DIRECTORY TRASH_DIRECTORY GIT_TEST_LONG
		# Run command; redirect its stderr to &4 as in
		# test_run_, but keep its stdout on our stdout even in
		# non-verbose mode.
		"$@" 2>&4
		if [ "$?" = 0 ]
		then
			if test $test_external_has_tap -eq 0; then
				test_ok_ "$descr"
			else
				say_color "" "# test_external test $descr was ok"
				test_success=$(($test_success + 1))
			fi
		else
			if test $test_external_has_tap -eq 0; then
				test_failure_ "$descr" "$@"
			else
				say_color error "# test_external test $descr failed: $@"
				test_failure=$(($test_failure + 1))
			fi
		fi
	fi
}

# Like test_external, but in addition tests that the command generated
# no output on stderr.
test_external_without_stderr () {
	# The temporary file has no (and must have no) security
	# implications.
	tmp=${TMPDIR:-/tmp}
	stderr="$tmp/git-external-stderr.$$.tmp"
	test_external "$@" 4> "$stderr"
	[ -f "$stderr" ] || error "Internal error: $stderr disappeared."
	descr="no stderr: $1"
	shift
	say >&3 "# expecting no stderr from previous command"
	if [ ! -s "$stderr" ]; then
		rm "$stderr"

		if test $test_external_has_tap -eq 0; then
			test_ok_ "$descr"
		else
			say_color "" "# test_external_without_stderr test $descr was ok"
			test_success=$(($test_success + 1))
		fi
	else
		if [ "$verbose" = t ]; then
			output=`echo; echo "# Stderr is:"; cat "$stderr"`
		else
			output=
		fi
		# rm first in case test_failure exits.
		rm "$stderr"
		if test $test_external_has_tap -eq 0; then
			test_failure_ "$descr" "$@" "$output"
		else
			say_color error "# test_external_without_stderr test $descr failed: $@: $output"
			test_failure=$(($test_failure + 1))
		fi
	fi
}

# debugging-friendly alternatives to "test [-f|-d|-e]"
# The commands test the existence or non-existence of $1. $2 can be
# given to provide a more precise diagnosis.
test_path_is_file () {
	if ! [ -f "$1" ]
	then
		echo "File $1 doesn't exist. $*"
		false
	fi
}

test_path_is_dir () {
	if ! [ -d "$1" ]
	then
		echo "Directory $1 doesn't exist. $*"
		false
	fi
}

# Check if the directory exists and is empty as expected, barf otherwise.
test_dir_is_empty () {
	test_path_is_dir "$1" &&
	if test -n "$(ls -a1 "$1" | egrep -v '^\.\.?$')"
	then
		echo "Directory '$1' is not empty, it contains:"
		ls -la "$1"
		return 1
	fi
}

test_path_is_missing () {
	if [ -e "$1" ]
	then
		echo "Path exists:"
		ls -ld "$1"
		if [ $# -ge 1 ]; then
			echo "$*"
		fi
		false
	fi
}

# test_line_count checks that a file has the number of lines it
# ought to. For example:
#
#	test_expect_success 'produce exactly one line of output' '
#		do something >output &&
#		test_line_count = 1 output
#	'
#
# is like "test $(wc -l <output) = 1" except that it passes the
# output through when the number of lines is wrong.

test_line_count () {
	if test $# != 3
	then
		error "bug in the test script: not 3 parameters to test_line_count"
	elif ! test $(wc -l <"$3") "$1" "$2"
	then
		echo "test_line_count: line count for $3 !$1 $2"
		cat "$3"
		return 1
	fi
}

# This is not among top-level (test_expect_success | test_expect_failure)
# but is a prefix that can be used in the test script, like:
#
#	test_expect_success 'complain and die' '
#           do something &&
#           do something else &&
#	    test_must_fail git checkout ../outerspace
#	'
#
# Writing this as "! git checkout ../outerspace" is wrong, because
# the failure could be due to a segv.  We want a controlled failure.

test_must_fail () {
	"$@"
	exit_code=$?
	if test $exit_code = 0; then
		echo >&2 "test_must_fail: command succeeded: $*"
		return 1
	elif test $exit_code -gt 129 && test $exit_code -le 192; then
		echo >&2 "test_must_fail: died by signal: $*"
		return 1
	elif test $exit_code = 127; then
		echo >&2 "test_must_fail: command not found: $*"
		return 1
	elif test $exit_code = 126; then
		echo >&2 "test_must_fail: valgrind error: $*"
		return 1
	fi
	return 0
}

# Similar to test_must_fail, but tolerates success, too.  This is
# meant to be used in contexts like:
#
#	test_expect_success 'some command works without configuration' '
#		test_might_fail git config --unset all.configuration &&
#		do something
#	'
#
# Writing "git config --unset all.configuration || :" would be wrong,
# because we want to notice if it fails due to segv.

test_might_fail () {
	"$@"
	exit_code=$?
	if test $exit_code -gt 129 && test $exit_code -le 192; then
		echo >&2 "test_might_fail: died by signal: $*"
		return 1
	elif test $exit_code = 127; then
		echo >&2 "test_might_fail: command not found: $*"
		return 1
	fi
	return 0
}

# Similar to test_must_fail and test_might_fail, but check that a
# given command exited with a given exit code. Meant to be used as:
#
#	test_expect_success 'Merge with d/f conflicts' '
#		test_expect_code 1 git merge "merge msg" B master
#	'

test_expect_code () {
	want_code=$1
	shift
	"$@"
	exit_code=$?
	if test $exit_code = $want_code
	then
		return 0
	fi

	echo >&2 "test_expect_code: command exited with $exit_code, we wanted $want_code $*"
	return 1
}

# test_cmp is a helper function to compare actual and expected output.
# You can use it like:
#
#	test_expect_success 'foo works' '
#		echo expected >expected &&
#		foo >actual &&
#		test_cmp expected actual
#	'
#
# This could be written as either "cmp" or "diff -u", but:
# - cmp's output is not nearly as easy to read as diff -u
# - not all diff versions understand "-u"

test_cmp() {
	$GIT_TEST_CMP "$@"
}

# test_cmp_bin - helper to compare binary files

test_cmp_bin() {
	cmp "$@"
}

# Call any command "$@" but be more verbose about its
# failure. This is handy for commands like "test" which do
# not output anything when they fail.
verbose () {
	"$@" && return 0
	echo >&2 "command failed: $(git rev-parse --sq-quote "$@")"
	return 1
}

# Check if the file expected to be empty is indeed empty, and barfs
# otherwise.

test_must_be_empty () {
	if test -s "$1"
	then
		echo "'$1' is not empty, it contains:"
		cat "$1"
		return 1
	fi
}

# Tests that its two parameters refer to the same revision
test_cmp_rev () {
	git rev-parse --verify "$1" >expect.rev &&
	git rev-parse --verify "$2" >actual.rev &&
	test_cmp expect.rev actual.rev
}

# Print a sequence of numbers or letters in increasing order.  This is
# similar to GNU seq(1), but the latter might not be available
# everywhere (and does not do letters).  It may be used like:
#
#	for i in `test_seq 100`; do
#		for j in `test_seq 10 20`; do
#			for k in `test_seq a z`; do
#				echo $i-$j-$k
#			done
#		done
#	done

test_seq () {
	case $# in
	1)	set 1 "$@" ;;
	2)	;;
	*)	error "bug in the test script: not 1 or 2 parameters to test_seq" ;;
	esac
	perl -le 'print for $ARGV[0]..$ARGV[1]' -- "$@"
}

# This function can be used to schedule some commands to be run
# unconditionally at the end of the test to restore sanity:
#
#	test_expect_success 'test core.capslock' '
#		git config core.capslock true &&
#		test_when_finished "git config --unset core.capslock" &&
#		hello world
#	'
#
# That would be roughly equivalent to
#
#	test_expect_success 'test core.capslock' '
#		git config core.capslock true &&
#		hello world
#		git config --unset core.capslock
#	'
#
# except that the greeting and config --unset must both succeed for
# the test to pass.
#
# Note that under --immediate mode, no clean-up is done to help diagnose
# what went wrong.

test_when_finished () {
	test_cleanup="{ $*
		} && (exit \"\$eval_ret\"); eval_ret=\$?; $test_cleanup"
}

# Most tests can use the created repository, but some may need to create more.
# Usage: test_create_repo <directory>
test_create_repo () {
	test "$#" = 1 ||
	error "bug in the test script: not 1 parameter to test-create-repo"
	repo="$1"
	mkdir -p "$repo"
	(
		cd "$repo" || error "Cannot setup test environment"
		"$GIT_EXEC_PATH/git-init" "--template=$GIT_BUILD_DIR/templates/blt/" >&3 2>&4 ||
		error "cannot run git init -- have you built things yet?"
		mv .git/hooks .git/hooks-disabled
	) || exit
}

# This function helps on symlink challenged file systems when it is not
# important that the file system entry is a symbolic link.
# Use test_ln_s_add instead of "ln -s x y && git add y" to add a
# symbolic link entry y to the index.

test_ln_s_add () {
	if test_have_prereq SYMLINKS
	then
		ln -s "$1" "$2" &&
		git update-index --add "$2"
	else
		printf '%s' "$1" >"$2" &&
		ln_s_obj=$(git hash-object -w "$2") &&
		git update-index --add --cacheinfo 120000 $ln_s_obj "$2"
	fi
}

# This function writes out its parameters, one per line
test_write_lines () {
	printf "%s\n" "$@"
}

perl () {
	command "$PERL_PATH" "$@"
}

# Is the value one of the various ways to spell a boolean true/false?
test_normalize_bool () {
	git -c magic.variable="$1" config --bool magic.variable 2>/dev/null
}

# Given a variable $1, normalize the value of it to one of "true",
# "false", or "auto" and store the result to it.
#
#     test_tristate GIT_TEST_HTTPD
#
# A variable set to an empty string is set to 'false'.
# A variable set to 'false' or 'auto' keeps its value.
# Anything else is set to 'true'.
# An unset variable defaults to 'auto'.
#
# The last rule is to allow people to set the variable to an empty
# string and export it to decline testing the particular feature
# for versions both before and after this change.  We used to treat
# both unset and empty variable as a signal for "do not test" and
# took any non-empty string as "please test".

test_tristate () {
	if eval "test x\"\${$1+isset}\" = xisset"
	then
		# explicitly set
		eval "
			case \"\$$1\" in
			'')	$1=false ;;
			auto)	;;
			*)	$1=\$(test_normalize_bool \$$1 || echo true) ;;
			esac
		"
	else
		eval "$1=auto"
	fi
}

# Exit the test suite, either by skipping all remaining tests or by
# exiting with an error. If "$1" is "auto", we then we assume we were
# opportunistically trying to set up some tests and we skip. If it is
# "true", then we report a failure.
#
# The error/skip message should be given by $2.
#
test_skip_or_die () {
	case "$1" in
	auto)
		skip_all=$2
		test_done
		;;
	true)
		error "$2"
		;;
	*)
		error "BUG: test tristate is '$1' (real error: $2)"
	esac
}

# The following mingw_* functions obey POSIX shell syntax, but are actually
# bash scripts, and are meant to be used only with bash on Windows.

# A test_cmp function that treats LF and CRLF equal and avoids to fork
# diff when possible.
mingw_test_cmp () {
	# Read text into shell variables and compare them. If the results
	# are different, use regular diff to report the difference.
	local test_cmp_a= test_cmp_b=

	# When text came from stdin (one argument is '-') we must feed it
	# to diff.
	local stdin_for_diff=

	# Since it is difficult to detect the difference between an
	# empty input file and a failure to read the files, we go straight
	# to diff if one of the inputs is empty.
	if test -s "$1" && test -s "$2"
	then
		# regular case: both files non-empty
		mingw_read_file_strip_cr_ test_cmp_a <"$1"
		mingw_read_file_strip_cr_ test_cmp_b <"$2"
	elif test -s "$1" && test "$2" = -
	then
		# read 2nd file from stdin
		mingw_read_file_strip_cr_ test_cmp_a <"$1"
		mingw_read_file_strip_cr_ test_cmp_b
		stdin_for_diff='<<<"$test_cmp_b"'
	elif test "$1" = - && test -s "$2"
	then
		# read 1st file from stdin
		mingw_read_file_strip_cr_ test_cmp_a
		mingw_read_file_strip_cr_ test_cmp_b <"$2"
		stdin_for_diff='<<<"$test_cmp_a"'
	fi
	test -n "$test_cmp_a" &&
	test -n "$test_cmp_b" &&
	test "$test_cmp_a" = "$test_cmp_b" ||
	eval "diff -u \"\$@\" $stdin_for_diff"
}

# $1 is the name of the shell variable to fill in
mingw_read_file_strip_cr_ () {
	# Read line-wise using LF as the line separator
	# and use IFS to strip CR.
	local line
	while :
	do
		if IFS=$'\r' read -r -d $'\n' line
		then
			# good
			line=$line$'\n'
		else
			# we get here at EOF, but also if the last line
			# was not terminated by LF; in the latter case,
			# some text was read
			if test -z "$line"
			then
				# EOF, really
				break
			fi
		fi
		eval "$1=\$$1\$line"
	done
}