tests: use "test_cmp", not "diff", when verifying the result

In tests, call test_cmp rather than raw diff where possible (i.e. if
the output does not go to a pipe), to allow the use of, say, 'cmp'
when the default 'diff -u' is not compatible with a vendor diff.

When that is not possible, use $DIFF, as set in GIT-BUILD-OPTIONS.

Signed-off-by: Gary V. Vaughan <gary@thewrittenword.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/t/t4124-apply-ws-rule.sh b/t/t4124-apply-ws-rule.sh
index fb9ad24..bef3bcb 100755
--- a/t/t4124-apply-ws-rule.sh
+++ b/t/t4124-apply-ws-rule.sh
@@ -44,7 +44,7 @@ test_fix () {
 	apply_patch --whitespace=fix || return 1
 
 	# find touched lines
-	diff file target | sed -n -e "s/^> //p" >fixed
+	$DIFF file target | sed -n -e "s/^> //p" >fixed
 
 	# the changed lines are all expeced to change
 	fixed_cnt=$(wc -l <fixed)
@@ -85,14 +85,14 @@ test_expect_success setup '
 test_expect_success 'whitespace=nowarn, default rule' '
 
 	apply_patch --whitespace=nowarn &&
-	diff file target
+	test_cmp file target
 
 '
 
 test_expect_success 'whitespace=warn, default rule' '
 
 	apply_patch --whitespace=warn &&
-	diff file target
+	test_cmp file target
 
 '
 
@@ -108,7 +108,7 @@ test_expect_success 'whitespace=error-all, no rule' '
 
 	git config core.whitespace -trailing,-space-before,-indent &&
 	apply_patch --whitespace=error-all &&
-	diff file target
+	test_cmp file target
 
 '
 
@@ -117,7 +117,7 @@ test_expect_success 'whitespace=error-all, no rule (attribute)' '
 	git config --unset core.whitespace &&
 	echo "target -whitespace" >.gitattributes &&
 	apply_patch --whitespace=error-all &&
-	diff file target
+	test_cmp file target
 
 '