Make the serialization of IPC::Messages inside other IPC::Messages independent

ipc/ipc_message_utils_unittest.cc

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ipc/ipc_message.h"
+#include "ipc/ipc_message_utils.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace IPC {
+
+// Tests nesting of messages as parameters to other messages.
+TEST(IPCMessageUtilsTest, NestedMessages) {
+  int32 nested_routing = 12;
+  uint32 nested_type = 78;
+  int nested_content = 456789;
+  Message::PriorityValue nested_priority = Message::PRIORITY_HIGH;
+  Message nested_msg(nested_routing, nested_type, nested_priority);
+  nested_msg.set_sync();
+  ParamTraits<int>::Write(&nested_msg, nested_content);
+
+  // Outer message contains the nested one as its parameter.
+  int32 outer_routing = 91;
+  uint32 outer_type = 88;
+  Message::PriorityValue outer_priority = Message::PRIORITY_NORMAL;
+  Message outer_msg(outer_routing, outer_type, outer_priority);
+  ParamTraits<Message>::Write(&outer_msg, nested_msg);
+
+  // Read back the nested message.
+  PickleIterator iter(outer_msg);
+  IPC::Message result_msg;
+  ASSERT_TRUE(ParamTraits<Message>::Read(&outer_msg, &iter, &result_msg));
+
+  // Verify nested message headers.
+  EXPECT_EQ(nested_msg.routing_id(), result_msg.routing_id());
+  EXPECT_EQ(nested_msg.type(), result_msg.type());
+  EXPECT_EQ(nested_msg.priority(), result_msg.priority());
+  EXPECT_EQ(nested_msg.flags(), result_msg.flags());
+
+  // Verify nested message content
+  PickleIterator nested_iter(nested_msg);
+  int result_content = 0;
+  ASSERT_TRUE(ParamTraits<int>::Read(&nested_msg, &nested_iter,
+                                     &result_content));
+  EXPECT_EQ(nested_content, result_content);
+
+  // Try reading past the ends for both messages and make sure it fails.
+  IPC::Message dummy;
+  ASSERT_FALSE(ParamTraits<Message>::Read(&outer_msg, &iter, &dummy));
+  ASSERT_FALSE(ParamTraits<int>::Read(&nested_msg, &nested_iter,
+                                      &result_content));
+}
+
+}  // namespace IPC