Mojo: Fix wrapping of invalid SharedMemoryHandles.

mojo/public/cpp/system/platform_handle.cc

 // Copyright 2016 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/public/cpp/system/platform_handle.h"
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
 #include <mach/mach.h>
 #include "base/mac/mach_logging.h"
 #endif
@@ skipping 48 matching lines @@
     *file = PlatformFileFromPlatformHandleValue(platform_handle.value);
   }
 
   return MOJO_RESULT_OK;
 }
 
 ScopedSharedBufferHandle WrapSharedMemoryHandle(
     const base::SharedMemoryHandle& memory_handle,
     size_t size,
     bool read_only) {
+#if defined(OS_POSIX) && !(defined(OS_MACOSX) && !defined(OS_IOS))
+  if (memory_handle == base::kInvalidPlatformFile)

[yzshen1, 2016/12/15 20:26:43]

They are not compatible for comparison?

+    return ScopedSharedBufferHandle();
+#else
+  if (!memory_handle.IsValid())
+    return ScopedSharedBufferHandle();
+#endif
   MojoPlatformHandle platform_handle;
   platform_handle.struct_size = sizeof(MojoPlatformHandle);
   platform_handle.type = kPlatformSharedBufferHandleType;
 #if defined(OS_MACOSX) && !defined(OS_IOS)
   platform_handle.value =
       static_cast<uint64_t>(memory_handle.GetMemoryObject());
 #elif defined(OS_POSIX)
   platform_handle.value = PlatformHandleValueFromPlatformFile(memory_handle.fd);
 #elif defined(OS_WIN)
   platform_handle.value =
@@ skipping 10 matching lines @@
       &platform_handle, size, flags, &mojo_handle);
   CHECK_EQ(result, MOJO_RESULT_OK);
 
   return ScopedSharedBufferHandle(SharedBufferHandle(mojo_handle));
 }
 
 MojoResult UnwrapSharedMemoryHandle(ScopedSharedBufferHandle handle,
                                     base::SharedMemoryHandle* memory_handle,
                                     size_t* size,
                                     bool* read_only) {
+  if (!handle.is_valid())
+    return MOJO_RESULT_INVALID_ARGUMENT;
   MojoPlatformHandle platform_handle;
   platform_handle.struct_size = sizeof(MojoPlatformHandle);
 
   MojoPlatformSharedBufferHandleFlags flags;
   size_t num_bytes;
   MojoResult result = MojoUnwrapPlatformSharedBufferHandle(
       handle.release().value(), &platform_handle, &num_bytes, &flags);
   if (result != MOJO_RESULT_OK)
     return result;
 
@@ skipping 51 matching lines @@
   if (result != MOJO_RESULT_OK)
     return result;
 
   CHECK_EQ(platform_handle.type, MOJO_PLATFORM_HANDLE_TYPE_MACH_PORT);
   *port = static_cast<mach_port_t>(platform_handle.value);
   return MOJO_RESULT_OK;
 }
 #endif  // defined(OS_MACOSX) && !defined(OS_IOS)
 
 }  // namespace mojo