[PATCH] test-lib: Multi-prereq support only checked the last prereq

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

The support for multiple test prerequisites added by me in "test-lib:
Add support for multiple test prerequisites" was broken.

The clever for-loop (which I blindly copied from Junio) iterated over
each prerequisite and returned true/false within a case statement.
Thus only the last prerequisite in the list of prerequisites was ever
considered, the rest were ignored.

Fix that by changing the test_have_prereq code to something less
clever that keeps a count of the total prereqs and the ones we have
and compares the count at the end.

This comes with the added advantage that it's easy to list the missing
prerequisites in the test output.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---

I should have spotted this earlier.

 t/t0000-basic.sh |    6 +++++-
 t/test-lib.sh    |   21 ++++++++++++++++++---
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/t/t0000-basic.sh b/t/t0000-basic.sh
index 2887677..9602085 100755
--- a/t/t0000-basic.sh
+++ b/t/t0000-basic.sh
@@ -84,7 +84,11 @@ donthaveit=yes
 test_expect_success HAVEIT,DONTHAVEIT 'unmet prerequisites causes test to be skipped' '
     donthaveit=no
 '
-if test $haveit$donthaveit != yesyes
+donthaveiteither=yes
+test_expect_success DONTHAVEIT,HAVEIT 'unmet prerequisites causes test to be skipped' '
+    donthaveiteither=no
+'
+if test $haveit$donthaveit$donthaveiteither != yesyesyes
 then
 	say "bug in test framework: multiple prerequisite tags do not work reliably"
 	exit 1
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 4e73fff..8c8e129 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -337,15 +337,30 @@ test_have_prereq () {
 	IFS=,
 	set -- $*
 	IFS=$save_IFS
+
+	total_prereq=0
+	ok_prereq=0
+	missing_prereq=
+
 	for prerequisite
 	do
+		total_prereq=$(($total_prereq + 1))
 		case $satisfied in
 		*" $prerequisite "*)
-			: yes, have it ;;
+			ok_prereq=$(($ok_prereq + 1))
+			;;
 		*)
-			! : nope ;;
+			# Keep a list of missing prerequisites
+			if test -z "$missing_prereq"
+			then
+				missing_prereq=$prerequisite
+			else
+				missing_prereq="$prerequisite,$missing_prereq"
+			fi
 		esac
 	done
+
+	test $total_prereq = $ok_prereq
 }
 
 # You are not expected to call test_ok_ and test_failure_ directly, use
@@ -408,7 +423,7 @@ test_skip () {
 	case "$to_skip" in
 	t)
 		say_color skip >&3 "skipping test: $@"
-		say_color skip "ok $test_count # skip $1 (prereqs: $prereq)"
+		say_color skip "ok $test_count # skip $1 (missing $missing_prereq of $prereq)"
 		: true
 		;;
 	*)
-- 
1.7.2.1.295.gd03d