close #3667.

scala> def ser(o: AnyRef) = new java.io.ObjectOutputStream(new java.io.ByteArrayOutputStream()).writeObject(o)
ser: (o: AnyRef)Unit

scala> @serializable class Outer {
     |   case class Inner(x: Int)
     | }
defined class Outer

scala> val o = new Outer
o: Outer = Outer@34469729

scala> ser(new o.Inner(1))

scala> o.Inner // initialize the Inner$module field of o

res1: o.Inner.type = Inner

scala> ser(new o.Inner(1))
java.io.NotSerializableException: Outer$Inner$

review by extempore.

2 files changed, 2 insertions, 0 deletions

diff --git a/test/files/scalap/packageObject/result.test b/test/files/scalap/packageObject/result.test
index 6a8d6ae1d5..324992aae1 100644
--- a/test/files/scalap/packageObject/result.test
+++ b/test/files/scalap/packageObject/result.test
@@ -2,4 +2,5 @@ package object PackageObject extends java.lang.Object with scala.ScalaObject {
   def this() = { /* compiled code */ }
   type A = scala.Predef.String
   def foo(i : scala.Int) : scala.Int = { /* compiled code */ }
+  protected def readResolve() : java.lang.Object = { /* compiled code */ }
 }
diff --git a/test/files/scalap/traitObject/result.test b/test/files/scalap/traitObject/result.test
index 0d7de1535d..8978873fc7 100644
--- a/test/files/scalap/traitObject/result.test
+++ b/test/files/scalap/traitObject/result.test
@@ -5,4 +5,5 @@ trait TraitObject extends java.lang.Object with scala.ScalaObject {
 object TraitObject extends java.lang.Object with scala.ScalaObject {
   def this() = { /* compiled code */ }
   def bar : scala.Int = { /* compiled code */ }
+  protected def readResolve() : java.lang.Object = { /* compiled code */ }
 }