Fix and test case for #2168.

git-svn-id: http://lampsvn.epfl.ch/svn-repos/scala/scala/trunk@18352 5e8d7ff9-d8ef-0310-90f0-a4852d11357a

src/compiler/scala/tools/nsc/ast/TreeDSL.scala

@@ -114,6 +114,8 @@ trait TreeDSL {
       
       /** Casting & type tests -- working our way toward understanding exactly
        *  what differs between the different forms of IS and AS.
+       *
+       *  See ticket #2168 for one illustration of AS vs. AS_ANY.
        */
       def AS(tpe: Type)       = TypeApply(Select(target, Any_asInstanceOf), List(TypeTree(tpe)))
       def AS_ANY(tpe: Type)   = gen.mkAsInstanceOf(target, tpe)

src/compiler/scala/tools/nsc/matching/ParallelMatching.scala

@@ -988,9 +988,10 @@ trait ParallelMatching extends ast.TreeDSL {
         // dig out case field accessors that were buried in (***)
         val cfa         = if (pats.isCaseHead) casted.accessors else Nil
         val caseTemps   = srep.tvars match { case x :: xs if x == casted.sym => xs ; case x => x }
-        def castedScrut = typedValDef(casted.sym, scrut.id AS castedTpe)
+        def castedScrut = typedValDef(casted.sym, scrut.id AS_ANY castedTpe)
         def needCast    = if (casted.sym ne scrut.sym) List(castedScrut) else Nil 
         
+        
         val vdefs       = needCast ::: (
           for ((tmp, accessor) <- caseTemps zip cfa) yield
             typedValDef(tmp, typer typed fn(casted.id, accessor))

test/files/pos/bug2168.scala

@@ -0,0 +1,6 @@
+object Test extends Application {
+  def foo1(x: AnyRef) = x match { case x: Function0[_] => x() }
+  def foo2(x: AnyRef) = x match { case x: Function0[Any] => x() }
+}
+  
+