SI-8254 List SerializationProxy fails to default(Read/Write)Object

Added `defaultWriteObject` to the beginning of `writeObject` and `defaultReadObject` to the beginning of `readObject` as required by specs:
[writing](http://docs.oracle.com/javase/6/docs/platform/serialization/spec/output.html#861), [reading](http://docs.oracle.com/javase/6/docs/platform/serialization/spec/input.html#2971).

Verified that it is a no-op in terms of serialization stream (but it provides hooks that Infinispan and others may use).

No explicit tests.  If there is a change in serialization, t8549 will catch it.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/library/scala/collection/immutable/List.scala b/src/library/scala/collection/immutable/List.scala
index 254f14f13c..82e38d3549 100644
--- a/src/library/scala/collection/immutable/List.scala
+++ b/src/library/scala/collection/immutable/List.scala
@@ -462,6 +462,7 @@ object List extends SeqFactory[List] {
   private class SerializationProxy[A](@transient private var orig: List[A]) extends Serializable {
 
     private def writeObject(out: ObjectOutputStream) {
+      out.defaultWriteObject()
       var xs: List[A] = orig
       while (!xs.isEmpty) {
         out.writeObject(xs.head)
@@ -473,6 +474,7 @@ object List extends SeqFactory[List] {
     // Java serialization calls this before readResolve during de-serialization.
     // Read the whole list and store it in `orig`.
     private def readObject(in: ObjectInputStream) {
+      in.defaultReadObject()
       val builder = List.newBuilder[A]
       while (true) in.readObject match {
         case ListSerializeEnd =>