tests: dd: avoid false failure with no controlling terminal

* tests/dd/misc.sh: test -w /dev/tty is not a strong enough check,
we need to actually open /dev/tty to ensure it's available.
It's not available under setsid for example.

diff --git a/tests/dd/misc.sh b/tests/dd/misc.sh
index e6559bf16865eabdee754b171d645a2e8077ae39..aa776b13794abf8cc772022a3f9a40570f1c7032 100755 (executable)
--- a/tests/dd/misc.sh
+++ b/tests/dd/misc.sh
@@ -125,7 +125,7 @@ compare /dev/null $tmp_out || fail=1
 compare err_ok err || fail=1
 
 # Ensure of=/dev/tty is possible
-if test -c /dev/tty && test -w /dev/tty; then
+if test -c /dev/tty && >/dev/tty; then
   dd if=/dev/null of=/dev/tty || fail=1
 fi