t0024, t5000: clear variable UNZIP, use GIT_UNZIP instead

InfoZIP's unzip takes default parameters from the environment variable
UNZIP.  Unset it in the test library and use GIT_UNZIP for specifying
alternate versions of the unzip command instead.

t0024 wasn't even using variable for the actual extraction.  t5000
was, but when setting it to InfoZIP's unzip it would try to extract
from itself (because it treats the contents of $UNZIP as parameters),
which failed of course.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/t/t0024-crlf-archive.sh b/t/t0024-crlf-archive.sh
index ec6c1b3..080fe5c 100755
--- a/t/t0024-crlf-archive.sh
+++ b/t/t0024-crlf-archive.sh
@@ -3,7 +3,7 @@
 test_description='respect crlf in git archive'
 
 . ./test-lib.sh
-UNZIP=${UNZIP:-unzip}
+GIT_UNZIP=${GIT_UNZIP:-unzip}
 
 test_expect_success setup '
 
@@ -26,7 +26,7 @@
 
 '
 
-"$UNZIP" -v >/dev/null 2>&1
+"$GIT_UNZIP" -v >/dev/null 2>&1
 if [ $? -eq 127 ]; then
 	say "Skipping ZIP test, because unzip was not found"
 else
@@ -37,7 +37,7 @@
 
 	git archive --format=zip HEAD >test.zip &&
 
-	( mkdir unzipped && cd unzipped && unzip ../test.zip ) &&
+	( mkdir unzipped && cd unzipped && "$GIT_UNZIP" ../test.zip ) &&
 
 	test_cmp sample unzipped/sample
 
diff --git a/t/t5000-tar-tree.sh b/t/t5000-tar-tree.sh
index ecf00ed..1f7593d 100755
--- a/t/t5000-tar-tree.sh
+++ b/t/t5000-tar-tree.sh
@@ -25,7 +25,7 @@
 '
 
 . ./test-lib.sh
-UNZIP=${UNZIP:-unzip}
+GIT_UNZIP=${GIT_UNZIP:-unzip}
 GZIP=${GZIP:-gzip}
 GUNZIP=${GUNZIP:-gzip -d}
 
@@ -37,9 +37,9 @@
 	dir=$1
 	dir_with_prefix=$dir/$2
 
-	test_expect_success UNZIP " extract ZIP archive" "
-		(mkdir $dir && cd $dir && $UNZIP ../$zipfile)
-	"
+	test_expect_success UNZIP " extract ZIP archive" '
+		(mkdir $dir && cd $dir && "$GIT_UNZIP" ../$zipfile)
+	'
 
 	test_expect_success UNZIP " validate filenames" "
 		(cd ${dir_with_prefix}a && find .) | sort >$listfile &&
@@ -201,7 +201,7 @@
       test_cmp a/substfile2 g/prefix/a/substfile2
 '
 
-$UNZIP -v >/dev/null 2>&1
+"$GIT_UNZIP" -v >/dev/null 2>&1
 if [ $? -eq 127 ]; then
 	say "Skipping ZIP tests, because unzip was not found"
 else
diff --git a/t/test-lib.sh b/t/test-lib.sh
index 489bc80..c9a6b03 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -85,6 +85,7 @@
 		.*_TEST
 		PROVE
 		VALGRIND
+		UNZIP
 		PERF_AGGREGATING_LATER
 	));
 	my @vars = grep(/^GIT_/ && !/^GIT_($ok)/o, @env);
@@ -128,6 +129,7 @@
 unset CDPATH
 
 unset GREP_OPTIONS
+unset UNZIP
 
 case $(echo $GIT_TRACE |tr "[A-Z]" "[a-z]") in
 1|2|true)