Enforce/require MOJO_HANDLE_RIGHT_TRANSFER in sending handles via MojoWriteMessage().

mojo/edk/system/core_unittest.cc

 // Copyright 2013 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 "mojo/edk/system/core.h"
 
 #include <stdint.h>
 
 #include <limits>
 
@@ skipping 1774 matching lines @@
     EXPECT_EQ(MOJO_RESULT_OK,
               core()->WriteMessage(h0, NullUserPointer(), 0,
                                    MakeUserPointer(h_passed), 2,
                                    MOJO_WRITE_MESSAGE_FLAG_NONE));
 
     // Again, nothing bad happens, but again you can only close |h0|.
     EXPECT_EQ(MOJO_RESULT_OK, core()->Close(h0));
   }
 }
 
+// Tests not having versus not having the transfer right.
+TEST_F(CoreTest, MessagePipeBasicLocalHandlePassing4) {
+  MojoHandle h0 = MOJO_HANDLE_INVALID;
+  MojoHandle h1 = MOJO_HANDLE_INVALID;
+  EXPECT_EQ(MOJO_RESULT_OK,
+            core()->CreateMessagePipe(NullUserPointer(), MakeUserPointer(&h0),
+                                      MakeUserPointer(&h1)));
+
+  MojoHandle h_transferrable = MOJO_HANDLE_INVALID;
+  EXPECT_EQ(MOJO_RESULT_OK,
+            core()->CreateSharedBuffer(NullUserPointer(), 100,
+                                       MakeUserPointer(&h_transferrable)));
+  MojoHandle h_not_transferrable = MOJO_HANDLE_INVALID;
+  EXPECT_EQ(MOJO_RESULT_OK, core()->DuplicateHandleWithReducedRights(
+                                h_transferrable, MOJO_HANDLE_RIGHT_TRANSFER,
+                                MakeUserPointer(&h_not_transferrable)));
+
+  // We can send |h_transferrable|.
+  EXPECT_EQ(MOJO_RESULT_OK,
+            core()->WriteMessage(h0, NullUserPointer(), 0,
+                                 MakeUserPointer(&h_transferrable), 1,
+                                 MOJO_WRITE_MESSAGE_FLAG_NONE));
+
+  // But not |h_not_transferrable|.
+  EXPECT_EQ(MOJO_RESULT_PERMISSION_DENIED,
+            core()->WriteMessage(h0, NullUserPointer(), 0,
+                                 MakeUserPointer(&h_not_transferrable), 1,
+                                 MOJO_WRITE_MESSAGE_FLAG_NONE));
+
+  EXPECT_EQ(MOJO_RESULT_OK, core()->Close(h0));
+  EXPECT_EQ(MOJO_RESULT_OK, core()->Close(h1));
+  EXPECT_EQ(MOJO_RESULT_OK, core()->Close(h_not_transferrable));
+}
+
 struct TestAsyncWaiter {
   TestAsyncWaiter() : result(MOJO_RESULT_UNKNOWN) {}
 
   void Awake(MojoResult r) { result = r; }
 
   MojoResult result;
 };
 
 TEST_F(CoreTest, AsyncWait) {
   TestAsyncWaiter waiter;
@@ skipping 18 matching lines @@
 
   EXPECT_EQ(MOJO_RESULT_OK, core()->Close(h));
 }
 
 // TODO(vtl): Test |CreateSharedBuffer()|, |DuplicateBufferHandle()|, and
 // |MapBuffer()|.
 
 }  // namespace
 }  // namespace system
 }  // namespace mojo