[mojo-edk] Broadcast surprise port disruptions

mojo/edk/system/channel.cc

Index: mojo/edk/system/channel.cc
diff --git a/mojo/edk/system/channel.cc b/mojo/edk/system/channel.cc
index 79928845a4453b0648359677e486e8f7b56abc39..56509b5b609f44886a6b883ffaba121fb3d0daa9 100644
--- a/mojo/edk/system/channel.cc
+++ b/mojo/edk/system/channel.cc
@@ -121,12 +121,6 @@ Channel::Message::~Message() {
 // static
 Channel::MessagePtr Channel::Message::Deserialize(const void* data,
                                                   size_t data_num_bytes) {
-#if !defined(OS_WIN) && !(defined(OS_MACOSX) && !defined(OS_IOS))
-  // We only serialize messages into other messages when performing message
-  // relay on Windows and OSX.
-  NOTREACHED();
-  return nullptr;
-#else
   if (data_num_bytes < sizeof(Header))
     return nullptr;
 
@@ -137,6 +131,10 @@ Channel::MessagePtr Channel::Message::Deserialize(const void* data,
     return nullptr;
   }
 
+#if defined(MOJO_EDK_LEGACY_PROTOCOL)
+  size_t payload_size = data_num_bytes - sizeof(Header);
+  const char* payload = static_cast<const char*>(data) + sizeof(Header);
+#else
   if (header->num_bytes < header->num_header_bytes ||
       header->num_header_bytes < sizeof(Header)) {
     DLOG(ERROR) << "Decoding invalid message: " << header->num_bytes << " < "
@@ -145,6 +143,11 @@ Channel::MessagePtr Channel::Message::Deserialize(const void* data,
   }
 
   uint32_t extra_header_size = header->num_header_bytes - sizeof(Header);
+  size_t payload_size = data_num_bytes - header->num_header_bytes;
+  const char* payload =
+      static_cast<const char*>(data) + header->num_header_bytes;
+#endif  // defined(MOJO_EDK_LEGACY_PROTOCOL)
+
 #if defined(OS_WIN)
   uint32_t max_handles = extra_header_size / sizeof(HandleEntry);
 #elif defined(OS_MACOSX) && !defined(OS_IOS)
@@ -155,32 +158,34 @@ Channel::MessagePtr Channel::Message::Deserialize(const void* data,
   }
   uint32_t max_handles = (extra_header_size - sizeof(MachPortsExtraHeader)) /
       sizeof(MachPortsEntry);
-#endif
+#else
+  const uint32_t max_handles = 0;
+#endif  // defined(OS_WIN)
+
   if (header->num_handles > max_handles || max_handles > kMaxAttachedHandles) {
     DLOG(ERROR) << "Decoding invalid message:" << header->num_handles
                 << " > " << max_handles;
     return nullptr;
   }
 
-  MessagePtr message(new Message(data_num_bytes - header->num_header_bytes,
-                                 max_handles));
+  MessagePtr message(new Message(payload_size, max_handles));
   DCHECK_EQ(message->data_num_bytes(), data_num_bytes);
+
+  // Copy all payload bytes.
+  if (payload_size)
+    memcpy(message->mutable_payload(), payload, payload_size);
+
+#if !defined(MOJO_EDK_LEGACY_PROTOCOL)
   DCHECK_EQ(message->extra_header_size(), extra_header_size);
   DCHECK_EQ(message->header_->num_header_bytes, header->num_header_bytes);
 
-  if (data_num_bytes > header->num_header_bytes) {
-    // Copy all payload bytes.
-    memcpy(message->mutable_payload(),
-           static_cast<const char*>(data) + header->num_header_bytes,
-           data_num_bytes - header->num_header_bytes);
-  }
-
   if (message->extra_header_size()) {
     // Copy extra header bytes.
     memcpy(message->mutable_extra_header(),
            static_cast<const char*>(data) + sizeof(Header),
            message->extra_header_size());
   }
+#endif
 
   message->header_->num_handles = header->num_handles;
 #if defined(OS_WIN)
@@ -194,7 +199,6 @@ Channel::MessagePtr Channel::Message::Deserialize(const void* data,
 #endif
 
   return message;
-#endif
 }
 
 size_t Channel::Message::payload_size() const {