1 files changed, 16 insertions, 7 deletions
diff --git a/src/reflect/scala/reflect/internal/transform/Erasure.scala b/src/reflect/scala/reflect/internal/transform/Erasure.scala
index 01e28e5642..412c49f571 100644
--- a/src/reflect/scala/reflect/internal/transform/Erasure.scala
+++ b/src/reflect/scala/reflect/internal/transform/Erasure.scala
@@ -3,8 +3,6 @@ package reflect
 package internal
 package transform
 
-import Flags.{PARAMACCESSOR, METHOD}
-
 trait Erasure {
 
   val global: SymbolTable
@@ -114,8 +112,10 @@ trait Erasure {
     protected def eraseDerivedValueClassRef(tref: TypeRef): Type = erasedValueClassArg(tref)
 
     def apply(tp: Type): Type = tp match {
-      case ConstantType(_) =>
-        tp
+      case ConstantType(ct) =>
+        // erase classOf[List[_]] to classOf[List]. special case for classOf[Unit], avoid erasing to classOf[BoxedUnit].
+        if (ct.tag == ClazzTag && ct.typeValue.typeSymbol != UnitClass) ConstantType(Constant(apply(ct.typeValue)))
+        else tp
       case st: ThisType if st.sym.isPackageClass =>
         tp
       case st: SubType =>
@@ -123,7 +123,7 @@ trait Erasure {
       case tref @ TypeRef(pre, sym, args) =>
         if (sym == ArrayClass)
           if (unboundedGenericArrayLevel(tp) == 1) ObjectTpe
-          else if (args.head.typeSymbol.isBottomClass) arrayType(ObjectTpe)
+          else if (args.head.typeSymbol.isBottomClass)  arrayType(ObjectTpe)
           else typeRef(apply(pre), sym, args map applyInArray)
         else if (sym == AnyClass || sym == AnyValClass || sym == SingletonClass) ObjectTpe
         else if (sym == UnitClass) BoxedUnitTpe
@@ -166,7 +166,7 @@ trait Erasure {
 
   /**   The erasure |T| of a type T. This is:
    *
-   *   - For a constant type, itself.
+   *   - For a constant type classOf[T], classOf[|T|], unless T is Unit. For any other constant type, itself.
    *   - For a type-bounds structure, the erasure of its upper bound.
    *   - For every other singleton type, the erasure of its supertype.
    *   - For a typeref scala.Array+[T] where T is an abstract type, AnyRef.
@@ -282,8 +282,17 @@ trait Erasure {
   }
 
   object boxingErasure extends ScalaErasureMap {
+    private var boxPrimitives = true
+
+    override def applyInArray(tp: Type): Type = {
+      val saved = boxPrimitives
+      boxPrimitives = false
+      try super.applyInArray(tp)
+      finally boxPrimitives = saved
+    }
+
     override def eraseNormalClassRef(tref: TypeRef) =
-      if (isPrimitiveValueClass(tref.sym)) boxedClass(tref.sym).tpe
+      if (boxPrimitives && isPrimitiveValueClass(tref.sym)) boxedClass(tref.sym).tpe
       else super.eraseNormalClassRef(tref)
     override def eraseDerivedValueClassRef(tref: TypeRef) =
       super.eraseNormalClassRef(tref)