Merge branch 'jc/test-prereq'

Teaches the test framework to probe rarely used prerequistes lazily,
and make use of it for detecting SYMLINKS, CASE_INSENSITIVE_FS and
NKD/NKC MacOS x gotcha.

* jc/test-prereq:
  t3910: use the UTF8_NFD_TO_NFC test prereq
  test-lib: provide UTF8 behaviour as a prerequisite
  t0050: use the SYMLINKS test prereq
  t0050: use the CASE_INSENSITIVE_FS test prereq
  test-lib: provide case insensitivity as a prerequisite
  test: allow prerequisite to be evaluated lazily
  test: rename $satisfied to $satisfied_prereq

6 files changed, 233 insertions, 205 deletions

diff --git a/t/README b/t/README
index 4c3ea25e66..e4128e5769 100644
--- a/t/README
+++ b/t/README
@@ -625,6 +625,15 @@ use these, and "test_set_prereq" for how to define your own.
    Git was compiled with USE_LIBPCRE=YesPlease. Wrap any tests
    that use git-grep --perl-regexp or git-grep -P in these.
 
+ - CASE_INSENSITIVE_FS
+
+   Test is run on a case insensitive file system.
+
+ - UTF8_NFD_TO_NFC
+
+   Test is run on a filesystem which converts decomposed utf-8 (nfd)
+   to precomposed utf-8 (nfc).
+
 Tips for Writing Tests
 ----------------------
 
diff --git a/t/t0003-attributes.sh b/t/t0003-attributes.sh
index 51f3045ba4..febc45c9cc 100755
--- a/t/t0003-attributes.sh
+++ b/t/t0003-attributes.sh
@@ -123,16 +123,6 @@ test_expect_success 'attribute matching is case insensitive when core.ignorecase
 
 '
 
-test_expect_success 'check whether FS is case-insensitive' '
-	mkdir junk &&
-	echo good >junk/CamelCase &&
-	echo bad >junk/camelcase &&
-	if test "$(cat junk/CamelCase)" != good
-	then
-		test_set_prereq CASE_INSENSITIVE_FS
-	fi
-'
-
 test_expect_success CASE_INSENSITIVE_FS 'additional case insensitivity tests' '
 	test_must_fail attr_check a/B/D/g "a/b/d/*" "-c core.ignorecase=0" &&
 	test_must_fail attr_check A/B/D/NO "a/b/d/*" "-c core.ignorecase=0" &&
diff --git a/t/t0050-filesystem.sh b/t/t0050-filesystem.sh
index 1542cf6a13..78816d9d93 100755
--- a/t/t0050-filesystem.sh
+++ b/t/t0050-filesystem.sh
@@ -7,48 +7,26 @@ test_description='Various filesystem issues'
 auml=$(printf '\303\244')
 aumlcdiar=$(printf '\141\314\210')
 
-case_insensitive=
-unibad=
-no_symlinks=
-test_expect_success 'see what we expect' '
-
-	test_case=test_expect_success &&
-	test_unicode=test_expect_success &&
-	mkdir junk &&
-	echo good >junk/CamelCase &&
-	echo bad >junk/camelcase &&
-	if test "$(cat junk/CamelCase)" != good
-	then
-		test_case=test_expect_failure &&
-		case_insensitive=t
-	fi &&
-	rm -fr junk &&
-	mkdir junk &&
-	>junk/"$auml" &&
-	case "$(cd junk && echo *)" in
-	"$aumlcdiar")
-		test_unicode=test_expect_failure &&
-		unibad=t
-		;;
-	*)	;;
-	esac &&
-	rm -fr junk &&
-	{
-		ln -s x y 2> /dev/null &&
-		test -h y 2> /dev/null ||
-		no_symlinks=1 &&
-		rm -f y
-	}
-'
-
-test "$case_insensitive" &&
+if test_have_prereq CASE_INSENSITIVE_FS
+then
 	say "will test on a case insensitive filesystem"
-test "$unibad" &&
+	test_case=test_expect_failure
+else
+	test_case=test_expect_success
+fi
+
+if test_have_prereq UTF8_NFD_TO_NFC
+then
 	say "will test on a unicode corrupting filesystem"
-test "$no_symlinks" &&
+	test_unicode=test_expect_failure
+else
+	test_unicode=test_expect_success
+fi
+
+test_have_prereq SYMLINKS ||
 	say "will test on a filesystem lacking symbolic links"
 
-if test "$case_insensitive"
+if test_have_prereq CASE_INSENSITIVE_FS
 then
 test_expect_success "detection of case insensitive filesystem during repo init" '
 
@@ -62,18 +40,18 @@ test_expect_success "detection of case insensitive filesystem during repo init"
 '
 fi
 
-if test "$no_symlinks"
+if test_have_prereq SYMLINKS
 then
 test_expect_success "detection of filesystem w/o symlink support during repo init" '
 
-	v=$(git config --bool core.symlinks) &&
-	test "$v" = false
+	test_must_fail git config --bool core.symlinks ||
+	test "$(git config --bool core.symlinks)" = true
 '
 else
 test_expect_success "detection of filesystem w/o symlink support during repo init" '
 
-	test_must_fail git config --bool core.symlinks ||
-	test "$(git config --bool core.symlinks)" = true
+	v=$(git config --bool core.symlinks) &&
+	test "$v" = false
 '
 fi
 
diff --git a/t/t3910-mac-os-precompose.sh b/t/t3910-mac-os-precompose.sh
index 88b7a20c11..5fe57c5438 100755
--- a/t/t3910-mac-os-precompose.sh
+++ b/t/t3910-mac-os-precompose.sh
@@ -7,158 +7,147 @@ test_description='utf-8 decomposed (nfd) converted to precomposed (nfc)'
 
 . ./test-lib.sh
 
+if ! test_have_prereq UTF8_NFD_TO_NFC
+then
+	skip_all="filesystem does not corrupt utf-8"
+	test_done
+fi
+
+# create utf-8 variables
 Adiarnfc=`printf '\303\204'`
 Adiarnfd=`printf 'A\314\210'`
 
-# check if the feature is compiled in
-mkdir junk &&
->junk/"$Adiarnfc" &&
-case "$(cd junk && echo *)" in
-	"$Adiarnfd")
-	test_nfd=1
-	;;
-	*)	;;
-esac
-rm -rf junk
+Odiarnfc=`printf '\303\226'`
+Odiarnfd=`printf 'O\314\210'`
+AEligatu=`printf '\303\206'`
+Invalidu=`printf '\303\377'`
 
 
-if test "$test_nfd"
-then
-	# create more utf-8 variables
-	Odiarnfc=`printf '\303\226'`
-	Odiarnfd=`printf 'O\314\210'`
-	AEligatu=`printf '\303\206'`
-	Invalidu=`printf '\303\377'`
+#Create a string with 255 bytes (decomposed)
+Alongd=$Adiarnfd$Adiarnfd$Adiarnfd$Adiarnfd$Adiarnfd$Adiarnfd$Adiarnfd #21 Byte
+Alongd=$Alongd$Alongd$Alongd                                           #63 Byte
+Alongd=$Alongd$Alongd$Alongd$Alongd$Adiarnfd                           #255 Byte
 
+#Create a string with 254 bytes (precomposed)
+Alongc=$AEligatu$AEligatu$AEligatu$AEligatu$AEligatu #10 Byte
+Alongc=$Alongc$Alongc$Alongc$Alongc$Alongc           #50 Byte
+Alongc=$Alongc$Alongc$Alongc$Alongc$Alongc           #250 Byte
+Alongc=$Alongc$AEligatu$AEligatu                     #254 Byte
 
-	#Create a string with 255 bytes (decomposed)
-	Alongd=$Adiarnfd$Adiarnfd$Adiarnfd$Adiarnfd$Adiarnfd$Adiarnfd$Adiarnfd #21 Byte
-	Alongd=$Alongd$Alongd$Alongd                                           #63 Byte
-	Alongd=$Alongd$Alongd$Alongd$Alongd$Adiarnfd                           #255 Byte
-
-	#Create a string with 254 bytes (precomposed)
-	Alongc=$AEligatu$AEligatu$AEligatu$AEligatu$AEligatu #10 Byte
-	Alongc=$Alongc$Alongc$Alongc$Alongc$Alongc           #50 Byte
-	Alongc=$Alongc$Alongc$Alongc$Alongc$Alongc           #250 Byte
-	Alongc=$Alongc$AEligatu$AEligatu                     #254 Byte
-
-	test_expect_success "detect if nfd needed" '
-		precomposeunicode=`git config core.precomposeunicode` &&
-		test "$precomposeunicode" = false &&
-		git config core.precomposeunicode true
-	'
-	test_expect_success "setup" '
-		>x &&
-		git add x &&
-		git commit -m "1st commit" &&
-		git rm x &&
-		git commit -m "rm x"
-	'
-	test_expect_success "setup case mac" '
-		git checkout -b mac_os
-	'
-	# This will test nfd2nfc in readdir()
-	test_expect_success "add file Adiarnfc" '
-		echo f.Adiarnfc >f.$Adiarnfc &&
-		git add f.$Adiarnfc &&
-		git commit -m "add f.$Adiarnfc"
-	'
-	# This will test nfd2nfc in git stage()
-	test_expect_success "stage file d.Adiarnfd/f.Adiarnfd" '
-		mkdir d.$Adiarnfd &&
-		echo d.$Adiarnfd/f.$Adiarnfd >d.$Adiarnfd/f.$Adiarnfd &&
-		git stage d.$Adiarnfd/f.$Adiarnfd &&
-		git commit -m "add d.$Adiarnfd/f.$Adiarnfd"
-	'
-	test_expect_success "add link Adiarnfc" '
-		ln -s d.$Adiarnfd/f.$Adiarnfd l.$Adiarnfc &&
-		git add l.$Adiarnfc &&
-		git commit -m "add l.Adiarnfc"
-	'
-	# This will test git log
-	test_expect_success "git log f.Adiar" '
-		git log f.$Adiarnfc > f.Adiarnfc.log &&
-		git log f.$Adiarnfd > f.Adiarnfd.log &&
-		test -s f.Adiarnfc.log &&
-		test -s f.Adiarnfd.log &&
-		test_cmp f.Adiarnfc.log f.Adiarnfd.log &&
-		rm f.Adiarnfc.log f.Adiarnfd.log
-	'
-	# This will test git ls-files
-	test_expect_success "git lsfiles f.Adiar" '
-		git ls-files f.$Adiarnfc > f.Adiarnfc.log &&
-		git ls-files f.$Adiarnfd > f.Adiarnfd.log &&
-		test -s f.Adiarnfc.log &&
-		test -s f.Adiarnfd.log &&
-		test_cmp f.Adiarnfc.log f.Adiarnfd.log &&
-		rm f.Adiarnfc.log f.Adiarnfd.log
-	'
-	# This will test git mv
-	test_expect_success "git mv" '
-		git mv f.$Adiarnfd f.$Odiarnfc &&
-		git mv d.$Adiarnfd d.$Odiarnfc &&
-		git mv l.$Adiarnfd l.$Odiarnfc &&
-		git commit -m "mv Adiarnfd Odiarnfc"
-	'
-	# Files can be checked out as nfc
-	# And the link has been corrected from nfd to nfc
-	test_expect_success "git checkout nfc" '
-		rm f.$Odiarnfc &&
-		git checkout f.$Odiarnfc
-	'
-	# Make it possible to checkout files with their NFD names
-	test_expect_success "git checkout file nfd" '
-		rm -f f.* &&
-		git checkout f.$Odiarnfd
-	'
-	# Make it possible to checkout links with their NFD names
-	test_expect_success "git checkout link nfd" '
-		rm l.* &&
-		git checkout l.$Odiarnfd
-	'
-	test_expect_success "setup case mac2" '
-		git checkout master &&
-		git reset --hard &&
-		git checkout -b mac_os_2
-	'
-	# This will test nfd2nfc in git commit
-	test_expect_success "commit file d2.Adiarnfd/f.Adiarnfd" '
-		mkdir d2.$Adiarnfd &&
-		echo d2.$Adiarnfd/f.$Adiarnfd >d2.$Adiarnfd/f.$Adiarnfd &&
-		git add d2.$Adiarnfd/f.$Adiarnfd &&
-		git commit -m "add d2.$Adiarnfd/f.$Adiarnfd" -- d2.$Adiarnfd/f.$Adiarnfd
-	'
-	test_expect_success "setup for long decomposed filename" '
-		git checkout master &&
-		git reset --hard &&
-		git checkout -b mac_os_long_nfd_fn
-	'
-	test_expect_success "Add long decomposed filename" '
-		echo longd >$Alongd &&
-		git add * &&
-		git commit -m "Long filename"
-	'
-	test_expect_success "setup for long precomposed filename" '
-		git checkout master &&
-		git reset --hard &&
-		git checkout -b mac_os_long_nfc_fn
-	'
-	test_expect_success "Add long precomposed filename" '
-		echo longc >$Alongc &&
-		git add * &&
-		git commit -m "Long filename"
-	'
-	# Test if the global core.precomposeunicode stops autosensing
-	# Must be the last test case
-	test_expect_success "respect git config --global core.precomposeunicode" '
-		git config --global core.precomposeunicode true &&
-		rm -rf .git &&
-		git init &&
-		precomposeunicode=`git config core.precomposeunicode` &&
-		test "$precomposeunicode" = "true"
-	'
-else
-	 say "Skipping nfc/nfd tests"
-fi
+test_expect_success "detect if nfd needed" '
+	precomposeunicode=`git config core.precomposeunicode` &&
+	test "$precomposeunicode" = false &&
+	git config core.precomposeunicode true
+'
+test_expect_success "setup" '
+	>x &&
+	git add x &&
+	git commit -m "1st commit" &&
+	git rm x &&
+	git commit -m "rm x"
+'
+test_expect_success "setup case mac" '
+	git checkout -b mac_os
+'
+# This will test nfd2nfc in readdir()
+test_expect_success "add file Adiarnfc" '
+	echo f.Adiarnfc >f.$Adiarnfc &&
+	git add f.$Adiarnfc &&
+	git commit -m "add f.$Adiarnfc"
+'
+# This will test nfd2nfc in git stage()
+test_expect_success "stage file d.Adiarnfd/f.Adiarnfd" '
+	mkdir d.$Adiarnfd &&
+	echo d.$Adiarnfd/f.$Adiarnfd >d.$Adiarnfd/f.$Adiarnfd &&
+	git stage d.$Adiarnfd/f.$Adiarnfd &&
+	git commit -m "add d.$Adiarnfd/f.$Adiarnfd"
+'
+test_expect_success "add link Adiarnfc" '
+	ln -s d.$Adiarnfd/f.$Adiarnfd l.$Adiarnfc &&
+	git add l.$Adiarnfc &&
+	git commit -m "add l.Adiarnfc"
+'
+# This will test git log
+test_expect_success "git log f.Adiar" '
+	git log f.$Adiarnfc > f.Adiarnfc.log &&
+	git log f.$Adiarnfd > f.Adiarnfd.log &&
+	test -s f.Adiarnfc.log &&
+	test -s f.Adiarnfd.log &&
+	test_cmp f.Adiarnfc.log f.Adiarnfd.log &&
+	rm f.Adiarnfc.log f.Adiarnfd.log
+'
+# This will test git ls-files
+test_expect_success "git lsfiles f.Adiar" '
+	git ls-files f.$Adiarnfc > f.Adiarnfc.log &&
+	git ls-files f.$Adiarnfd > f.Adiarnfd.log &&
+	test -s f.Adiarnfc.log &&
+	test -s f.Adiarnfd.log &&
+	test_cmp f.Adiarnfc.log f.Adiarnfd.log &&
+	rm f.Adiarnfc.log f.Adiarnfd.log
+'
+# This will test git mv
+test_expect_success "git mv" '
+	git mv f.$Adiarnfd f.$Odiarnfc &&
+	git mv d.$Adiarnfd d.$Odiarnfc &&
+	git mv l.$Adiarnfd l.$Odiarnfc &&
+	git commit -m "mv Adiarnfd Odiarnfc"
+'
+# Files can be checked out as nfc
+# And the link has been corrected from nfd to nfc
+test_expect_success "git checkout nfc" '
+	rm f.$Odiarnfc &&
+	git checkout f.$Odiarnfc
+'
+# Make it possible to checkout files with their NFD names
+test_expect_success "git checkout file nfd" '
+	rm -f f.* &&
+	git checkout f.$Odiarnfd
+'
+# Make it possible to checkout links with their NFD names
+test_expect_success "git checkout link nfd" '
+	rm l.* &&
+	git checkout l.$Odiarnfd
+'
+test_expect_success "setup case mac2" '
+	git checkout master &&
+	git reset --hard &&
+	git checkout -b mac_os_2
+'
+# This will test nfd2nfc in git commit
+test_expect_success "commit file d2.Adiarnfd/f.Adiarnfd" '
+	mkdir d2.$Adiarnfd &&
+	echo d2.$Adiarnfd/f.$Adiarnfd >d2.$Adiarnfd/f.$Adiarnfd &&
+	git add d2.$Adiarnfd/f.$Adiarnfd &&
+	git commit -m "add d2.$Adiarnfd/f.$Adiarnfd" -- d2.$Adiarnfd/f.$Adiarnfd
+'
+test_expect_success "setup for long decomposed filename" '
+	git checkout master &&
+	git reset --hard &&
+	git checkout -b mac_os_long_nfd_fn
+'
+test_expect_success "Add long decomposed filename" '
+	echo longd >$Alongd &&
+	git add * &&
+	git commit -m "Long filename"
+'
+test_expect_success "setup for long precomposed filename" '
+	git checkout master &&
+	git reset --hard &&
+	git checkout -b mac_os_long_nfc_fn
+'
+test_expect_success "Add long precomposed filename" '
+	echo longc >$Alongc &&
+	git add * &&
+	git commit -m "Long filename"
+'
+# Test if the global core.precomposeunicode stops autosensing
+# Must be the last test case
+test_expect_success "respect git config --global core.precomposeunicode" '
+	git config --global core.precomposeunicode true &&
+	rm -rf .git &&
+	git init &&
+	precomposeunicode=`git config core.precomposeunicode` &&
+	test "$precomposeunicode" = "true"
+'
 
 test_done
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 80daaca780..04b1a43ef2 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -221,9 +221,35 @@ write_script () {
 # capital letters by convention).
 
 test_set_prereq () {
-	satisfied="$satisfied$1 "
+	satisfied_prereq="$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
 }
-satisfied=" "
 
 test_have_prereq () {
 	# prerequisites can be concatenated with ','
@@ -238,8 +264,24 @@ test_have_prereq () {
 
 	for prerequisite
 	do
+		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 $satisfied in
+		case "$satisfied_prereq" in
 		*" $prerequisite "*)
 			ok_prereq=$(($ok_prereq + 1))
 			;;
diff --git a/t/test-lib.sh b/t/test-lib.sh
index bb4f8865b2..78c428619e 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -659,9 +659,29 @@ test_i18ngrep () {
 	fi
 }
 
-# test whether the filesystem supports symbolic links
-ln -s x y 2>/dev/null && test -h y 2>/dev/null && test_set_prereq SYMLINKS
-rm -f y
+test_lazy_prereq SYMLINKS '
+	# test whether the filesystem supports symbolic links
+	ln -s x y && test -h y
+'
+
+test_lazy_prereq CASE_INSENSITIVE_FS '
+	echo good >CamelCase &&
+	echo bad >camelcase &&
+	test "$(cat CamelCase)" != good
+'
+
+test_lazy_prereq UTF8_NFD_TO_NFC '
+	# check whether FS converts nfd unicode to nfc
+	auml=$(printf "\303\244")
+	aumlcdiar=$(printf "\141\314\210")
+	>"$auml" &&
+	case "$(echo *)" in
+	"$aumlcdiar")
+		true ;;
+	*)
+		false ;;
+	esac
+'
 
 # When the tests are run as root, permission tests will report that
 # things are writable when they shouldn't be.