Might make #973 go away.

src/main/resources/assets/opencomputers/lua/machine.lua

@@ -908,7 +908,7 @@ wrappedUserdataMeta = {
 local wrappedUserdata = setmetatable({}, wrappedUserdataMeta)
 
 local function processResult(result)
-  wrapUserdata(result) -- needed for metamethods.
+  result = wrapUserdata(result) -- needed for metamethods.
   if not result[1] then -- error that should be re-thrown.
     error(result[2], 0)
   else -- success or already processed error.
@@ -920,8 +920,9 @@ local function invoke(target, direct, ...)
   local result
   if direct then
     local args = table.pack(...) -- for unwrapping
-    unwrapUserdata(args)
+    args = unwrapUserdata(args)
     result = table.pack(target.invoke(table.unpack(args, 1, args.n)))
+    args = nil -- clear upvalue, avoids trying to persist it
     if result.n == 0 then -- limit for direct calls reached
       result = nil
     end
@@ -930,9 +931,10 @@ local function invoke(target, direct, ...)
   if not result then
     local args = table.pack(...) -- for access in closure
     result = select(1, coroutine.yield(function()
-      unwrapUserdata(args)
+      args = unwrapUserdata(args)
       local result = table.pack(target.invoke(table.unpack(args, 1, args.n)))
-      wrapUserdata(result)
+      args = nil -- clear upvalue, avoids trying to persist it
+      result = wrapUserdata(result)
       return result
     end))
   end
@@ -941,8 +943,9 @@ end
 
 local function udinvoke(f, data, ...)
   local args = table.pack(...)
-  unwrapUserdata(args)
+  args = unwrapUserdata(args)
   local result = table.pack(f(data, table.unpack(args)))
+  args = nil -- clear upvalue, avoids trying to persist it
   return processResult(result)
 end
 
@@ -1035,7 +1038,7 @@ function wrapUserdata(values)
     end
     return value
   end
-  wrapRecursively(values)
+  return wrapRecursively(values)
 end
 
 function unwrapUserdata(values)
@@ -1054,7 +1057,7 @@ function unwrapUserdata(values)
     end
     return value
   end
-  unwrapRecursively(values)
+  return unwrapRecursively(values)
 end
 
 -------------------------------------------------------------------------------
@@ -1343,13 +1346,14 @@ local function main()
 
     debug.sethook(co, checkDeadline, "", hookInterval)
     local result = table.pack(coroutine.resume(co, table.unpack(args, 1, args.n)))
+    args = nil -- clear upvalue, avoids trying to persist it
     if not result[1] then
       error(tostring(result[2]), 0)
     elseif coroutine.status(co) == "dead" then
       error("computer halted", 0)
     else
       args = table.pack(coroutine.yield(result[2])) -- system yielded value
-      wrapUserdata(args)
+      args = wrapUserdata(args)
     end
   end
 end

src/main/scala/li/cil/oc/server/component/InternetCard.scala

@@ -1,27 +1,15 @@
 package li.cil.oc.server.component
 
-import java.io.BufferedWriter
-import java.io.FileNotFoundException
-import java.io.IOException
-import java.io.InputStream
-import java.io.OutputStreamWriter
+import java.io.{BufferedWriter, FileNotFoundException, IOException, InputStream, OutputStreamWriter}
 import java.net._
 import java.nio.ByteBuffer
 import java.nio.channels.SocketChannel
-import java.util.concurrent.Callable
-import java.util.concurrent.ConcurrentLinkedQueue
-import java.util.concurrent.ExecutionException
-import java.util.concurrent.Future
+import java.util.concurrent.{Callable, ConcurrentLinkedQueue, ExecutionException, Future}
 
-import li.cil.oc.OpenComputers
-import li.cil.oc.Settings
-import li.cil.oc.api
-import li.cil.oc.api.Network
-import li.cil.oc.api.machine.Arguments
-import li.cil.oc.api.machine.Callback
-import li.cil.oc.api.machine.Context
+import li.cil.oc.{OpenComputers, Settings, api}
+import li.cil.oc.api.machine.{Arguments, Callback, Context}
 import li.cil.oc.api.network._
-import li.cil.oc.api.prefab
+import li.cil.oc.api.{Network, prefab}
 import li.cil.oc.api.prefab.AbstractValue
 import li.cil.oc.util.ExtendedNBT._
 import li.cil.oc.util.ThreadPoolFactory
@@ -239,28 +227,30 @@ object InternetCard {
       })
     }
 
-    private def checkConnected() = try {
+    private def checkConnected() = {
       if (owner.isEmpty) throw new IOException("connection lost")
-      if (isAddressResolved) channel.finishConnect()
-      else if (address.isCancelled) {
-        // I don't think this can ever happen, Justin Case.
-        channel.close()
-        throw new IOException("bad connection descriptor")
-      }
-      else if (address.isDone) {
-        // Check for errors.
-        try address.get catch {
-          case e: ExecutionException => throw e.getCause
+      try {
+        if (isAddressResolved) channel.finishConnect()
+        else if (address.isCancelled) {
+          // I don't think this can ever happen, Justin Case.
+          channel.close()
+          throw new IOException("bad connection descriptor")
         }
-        isAddressResolved = true
-        false
+        else if (address.isDone) {
+          // Check for errors.
+          try address.get catch {
+            case e: ExecutionException => throw e.getCause
+          }
+          isAddressResolved = true
+          false
+        }
+        else false
+      }
+      catch {
+        case t: Throwable =>
+          close()
+          false
       }
-      else false
-    }
-    catch {
-      case t: Throwable =>
-        close()
-        false
     }
 
     // This has to be an explicit internal class instead of an anonymous one
@@ -430,6 +420,7 @@ object InternetCard {
           throw new IOException(Option(e.getMessage).getOrElse(e.toString))
       }
     }
+
   }
 
 }