Fix remaining hk issues in pending

src/dotty/tools/dotc/core/TypeComparer.scala

@@ -580,7 +580,7 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling {
    */
   def compareHkApply2(tp1: Type, tp2: HKApply, tycon2: Type, args2: List[Type]): Boolean = {
     val tparams = tycon2.typeParams
-    assert(tparams.nonEmpty)
+    if (tparams.isEmpty) return false // can happen for ill-typed programs, e.g. neg/tcpoly_overloaded.scala
 
     /** True if `tp1` and `tp2` have compatible type constructors and their
      *  corresponding arguments are subtypes relative to their variance (see `isSubArgs`).

src/dotty/tools/dotc/typer/EtaExpansion.scala

@@ -142,7 +142,11 @@ object EtaExpansion {
     var ids: List[Tree] = mt.paramNames map (name => Ident(name).withPos(tree.pos))
     if (mt.paramTypes.nonEmpty && mt.paramTypes.last.isRepeatedParam)
       ids = ids.init :+ repeated(ids.last)
-    val body = Apply(lifted, ids)
+    var body: Tree = Apply(lifted, ids)
+    mt.resultType match {
+      case rt: MethodType if !rt.isImplicit => body = PostfixOp(body, nme.WILDCARD)
+      case _ =>
+    }
     val fn = untpd.Function(params, body)
     if (defs.nonEmpty) untpd.Block(defs.toList map untpd.TypedSplice, fn) else fn
   }

src/dotty/tools/dotc/typer/TypeAssigner.scala

@@ -94,12 +94,14 @@ trait TypeAssigner {
             case _ =>
               mapOver(tp)
           }
+        case tp @ HKApply(tycon, args) if toAvoid(tycon) =>
+          apply(tp.superType)
         case tp @ AppliedType(tycon, args) if toAvoid(tycon) =>
           val base = apply(tycon)
           var args = tp.baseArgInfos(base.typeSymbol)
           if (base.typeParams.length != args.length)
             args = base.typeParams.map(_.paramBounds)
-          base.appliedTo(args)
+          apply(base.appliedTo(args))
         case tp @ RefinedType(parent, name, rinfo) if variance > 0 =>
           val parent1 = apply(tp.parent)
           val refinedInfo1 = apply(rinfo)

tests/neg/tcpoly_overloaded.scala

@@ -0,0 +1,25 @@
+trait Monad[T <: Bound[T], MyType[x <: Bound[x]], Bound[_]] {
+  def flatMap[S <: RBound[S], RContainer[x <: RBound[x]], RBound[_],
+              Result[x <: RBound[x]] <: Monad[x, RContainer, RBound]]
+              (f: T => Result[S]): Result[S]
+  def flatMap[S <: RBound[S], RContainer[x <: RBound[x]], RBound[_],
+              Result[x <: RBound[x]] <: Monad[x, RContainer, RBound]]
+              (f: T => Result[S], foo: String): Result[S]
+  def flatMap[S <: Bound[S]]
+              (f: T => MyType[S], foo: Int): MyType[S]
+}
+
+trait Test {
+  def moo: MList[Int]
+  class MList[T](el: T) extends Monad[T, List, Any] {  // error: does not conform to upper bound // error
+    def flatMap[S <: RBound[S], RContainer[x <: RBound[x]], RBound[_],
+            Result[x <: RBound[x]] <: Monad[x, RContainer, RBound]]
+            (f: T => Result[S]): Result[S] = sys.error("foo")
+    def flatMap[S <: RBound[S], RContainer[x <: RBound[x]], RBound[_],
+            Result[x <: RBound[x]] <: Monad[x, RContainer, RBound]]
+            (f: T => Result[S], foo: String): Result[S]  = sys.error("foo")
+    def flatMap[S]
+            (f: T => List[S], foo: Int): List[S]  = sys.error("foo")
+  }
+  val l: MList[String] = moo.flatMap[String, List, Any, MList]((x: Int) => new MList("String")) // error: does not conform to upper bound // error
+}

tests/pending/pos/spec-traits.scala → tests/pos/spec-traits.scala

@@ -25,12 +25,12 @@ class Bug3307 {
 class Bug3301 {
   def t[A]: T[A] = sys.error("stub")
 
-  () => {
+  {() => {
     type X = Int
 
     def foo[X] = t[X]
     ()
-  }
+  }}
 }
 // issue 3299
 object Failure {

tests/pending/pos/tcpoly_bounds1.scala → tests/pos/tcpoly_bounds1.scala

@@ -7,7 +7,7 @@ object foo extends Foo[MyPair]
 
 
 trait Monad[m[x <: Bound[x]], Bound[x], a] // TODO: variances!
-trait ListMonad[a] extends Monad[List, Any, a]
+trait ListMonad[a] extends Monad[List, [X] -> Any, a] // Dotty difference: Any is not a legal argument for hk type.
 
 trait MyOrdered[a]
 trait MySet[x <: MyOrdered[x]]

tests/pending/pos/tcpoly_overloaded.scala → tests/pos/tcpoly_overloaded.scala

@@ -11,7 +11,7 @@ trait Monad[T <: Bound[T], MyType[x <: Bound[x]], Bound[_]] {
 
 trait Test {
   def moo: MList[Int]
-  class MList[T](el: T) extends Monad[T, List, Any] {
+  class MList[T](el: T) extends Monad[T, List, [X] -> Any] {
     def flatMap[S <: RBound[S], RContainer[x <: RBound[x]], RBound[_],
             Result[x <: RBound[x]] <: Monad[x, RContainer, RBound]]
             (f: T => Result[S]): Result[S] = sys.error("foo")
@@ -21,5 +21,5 @@ trait Test {
     def flatMap[S]
             (f: T => List[S], foo: Int): List[S]  = sys.error("foo")
   }
-  val l: MList[String] = moo.flatMap[String, List, Any, MList]((x: Int) => new MList("String"))
+  val l: MList[String] = moo.flatMap[String, List, [X] -> Any, MList]((x: Int) => new MList("String"))
 }

tests/pending/run/tcpoly_parseridioms.scala → tests/run/tcpoly_parseridioms.scala

@@ -108,5 +108,5 @@ trait ParserIdioms extends Parsers with Idioms {
 }
 
 object Test extends ParserIdioms with App {
-  println(expr("12".toList))
+  assert(expr("12".toList).toString == "Success(List(),Plus(1,2))")
 }