check that a malformed truncated response to a TSIG query is handled

(cherry picked from commit 8bbf3eb5f3)

bin/tests/system/tsig/tests.sh

@@ -233,6 +233,13 @@ then
   fi
 fi
 
+echo_i "check that a malformed truncated response to a TSIG query is handled"
+ret=0
+$DIG -p $PORT @10.53.0.1 bad-tsig > dig.out.bad-tsig || ret=1
+grep "status: SERVFAIL" dig.out.bad-tsig > /dev/null || ret=1
+if [ $ret -eq 1 ] ; then
+    echo_i "failed"; status=1
+fi
 
 echo_i "exit status: $status"
 [ $status -eq 0 ] || exit 1