add test_cmp function for test scripts

Many scripts compare actual and expected output using
"diff -u". This is nicer than "cmp" because the output shows
how the two differ. However, not all versions of diff
understand -u, leading to unnecessary test failure.

This adds a test_cmp function to the test scripts and
switches all "diff -u" invocations to use it. The function
uses the contents of "$GIT_TEST_CMP" to compare its
arguments; the default is "diff -u".

On systems with a less-capable diff, you can do:

  GIT_TEST_CMP=cmp make test

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/t/t4125-apply-ws-fuzz.sh b/t/t4125-apply-ws-fuzz.sh
index d6f15be67..3b471b641 100755
--- a/t/t4125-apply-ws-fuzz.sh
+++ b/t/t4125-apply-ws-fuzz.sh
@@ -56,7 +56,7 @@ test_expect_success nofix '
 	git apply --whitespace=nowarn patch-1 &&
 
 	# The result should obviously match.
-	diff -u file-1 file
+	test_cmp file-1 file
 '
 
 test_expect_success 'withfix (forward)' '
@@ -70,7 +70,7 @@ test_expect_success 'withfix (forward)' '
 	git apply --whitespace=fix patch-0 &&
 	git apply --whitespace=fix patch-1 &&
 
-	diff -u file-fixed file
+	test_cmp file-fixed file
 '
 
 test_expect_success 'withfix (backward)' '
@@ -91,12 +91,12 @@ test_expect_success 'withfix (backward)' '
 
 	sed -e /h/d file-fixed >fixed-head &&
 	sed -e /h/d file >file-head &&
-	diff -u fixed-head file-head &&
+	test_cmp fixed-head file-head &&
 
 	sed -n -e /h/p file-fixed >fixed-tail &&
 	sed -n -e /h/p file >file-tail &&
 
-	! diff -u fixed-tail file-tail
+	! test_cmp fixed-tail file-tail
 
 '