Don't use `diff -u'. It's not portable.

Run `diff -c' only if cmp finds a difference.

diff --git a/tests/cp/same-file b/tests/cp/same-file
index ae077c8169786ab5fd02f3d1db23bf1fd74872c7..6752b4f0ed757dbc3a2b988e4db876a5d48d3936 100755 (executable)
--- a/tests/cp/same-file
+++ b/tests/cp/same-file
@@ -182,8 +182,10 @@ cat <<\EOF > $expected
 
 EOF
 
-# Uncomment this if you see a failure and want to try to diagnose it.
-diff -u $expected $actual 1>&2
+fail=0;
 
-cmp $expected $actual
-exit $?
+# Some folks don't have diff.
+cmp $expected $actual \
+  || { diff -c $expected $actual 1>&2; fail=1; }
+
+(exit $fail); exit