tests: init.sh: work also with any non-GNU diff that supports -u

* tests/init.sh: Relax check for diff -u support.
Rather than checking for GNU diff via --version, simply check
for support for -u itself.  Useful at least on OpenBSD 4.9.

diff --git a/tests/init.sh b/tests/init.sh
index 460937de4f9d2c7164c0990d11b94e808c32509b..12b3ca37e1292f8b27fde5ffe897a5348e823d30 100644 (file)
--- a/tests/init.sh
+++ b/tests/init.sh
@@ -221,7 +221,7 @@ export MALLOC_PERTURB_
 # a partition, or to undo any other global state changes.
 cleanup_ () { :; }
 
-if ( diff --version < /dev/null 2>&1 | grep GNU ) > /dev/null 2>&1; then
+if ( diff -u "$0" "$0" < /dev/null ) > /dev/null 2>&1; then
   compare () { diff -u "$@"; }
 elif ( cmp --version < /dev/null 2>&1 | grep GNU ) > /dev/null 2>&1; then
   compare () { cmp -s "$@"; }