Fix listening for multiple signals.

tests/standalone/io/signals_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import "dart:io";
 import "dart:convert";
 
 import "package:expect/expect.dart";
 import "package:async_helper/async_helper.dart";
 
@@ skipping 42 matching lines @@
       process.stderr.drain();
 
       var output = "";
       process.stdout.transform(UTF8.decoder)
         .listen((str) {
           output += str;
           if (output == 'ready\n') {
             process.kill(signal);
           }
         }, onDone: () {
-          Expect.equals('ready\ngot signal\n', output);
+          Expect.equals('ready\n$signal\n', output);
         });
       process.exitCode.then((exitCode) {
         Expect.equals(0, exitCode);
         asyncEnd();
       });
     });
 }
 
+void testMultipleSignals(List<ProcessSignal> signals) {
+  for (var signal in signals) {
+    asyncStart();
+    Process.start(Platform.executable,
+        [Platform.script.resolve('signal_test_script.dart').toFilePath()]
+            ..addAll(signals.map((s) => s.toString())))
+      .then((process) {
+        process.stdin.close();
+        process.stderr.drain();
+
+        var output = "";
+        process.stdout.transform(UTF8.decoder)
+          .listen((str) {
+            output += str;
+            if (output == 'ready\n') {
+              process.kill(signal);
+            }
+          }, onDone: () {
+            Expect.equals('ready\n$signal\n', output);
+          });
+        process.exitCode.then((exitCode) {
+          Expect.equals(0, exitCode);
+          asyncEnd();
+        });
+      });
+  }
+}
+
 
 void testListenCancel() {
   for (int i = 0; i < 10; i++) {
     ProcessSignal.SIGINT.watch().listen(null).cancel();
   }
 }
 
 void main() {
   testListenCancel();
   if (Platform.isWindows) return;
   testSignals(0, 0);
   testSignals(1, 0);
   testSignals(0, 1);
   testSignals(1, 1);
   testSignals(10, 10);
   testSignals(10, 1);
   testSignals(1, 10);
   testSignals(1, 0, 0, 1, true);
   testSignals(0, 1, 1, 0, true);
 
   testSignal(ProcessSignal.SIGHUP);
   testSignal(ProcessSignal.SIGINT);
   testSignal(ProcessSignal.SIGTERM);
   testSignal(ProcessSignal.SIGUSR1);
   testSignal(ProcessSignal.SIGUSR2);
   testSignal(ProcessSignal.SIGWINCH);
+
+  testMultipleSignals([
+      ProcessSignal.SIGHUP,
+      ProcessSignal.SIGINT,
+      ProcessSignal.SIGTERM,
+      ProcessSignal.SIGUSR1,
+      ProcessSignal.SIGUSR2,
+      ProcessSignal.SIGWINCH]);
 }