Error with wildcard type from TASTY

[nicolasstucki]

Fail to compile from TASTY

class Foo[A] {
  def baz(foo: Foo[_]): Unit = bar(foo)
  def bar[A](foo: Foo[A]): A = ???
}

Can be reproduced with

dotc <source>
dotc -decompile -Ycheck:all Test

exception while typing this.bar[Foo[_]#<parameter A of class Foo>](foo) of class class dotty.tools.dotc.ast.Trees$Apply # 68
exception while typing {
  this.bar[Foo[_]#<parameter A of class Foo>](foo)
  ()
} of class class dotty.tools.dotc.ast.Trees$Block # 70
exception while typing  def baz( foo: Foo[_ >: Nothing <: Any]): Unit = 
  {
    this.bar[Foo[_]#<parameter A of class Foo>](foo)
    ()
  } of class class dotty.tools.dotc.ast.Trees$DefDef # 50
exception while typing @scala.annotation.internal.SourceFile("tests/pos/i2250.scala")  class T ()
   extends
 Object() { 
   def baz( foo: Foo[_ >: Nothing <: Any]): Unit = 
    {
      this.bar[Foo[_]#<parameter A of class Foo>](foo)
      ()
    }
   def bar[ A]( foo: Foo[A]): A = ???
} of class class dotty.tools.dotc.ast.Trees$TypeDef # 15
exception while typing package <empty> {
  @scala.annotation.internal.SourceFile("tests/pos/i2250.scala")  class T ()
     extends
   Object() { 
     def baz( foo: Foo[_ >: Nothing <: Any]): Unit = 
      {
        this.bar[Foo[_]#<parameter A of class Foo>](foo)
        ()
      }
     def bar[ A]( foo: Foo[A]): A = ???
  }
} of class class dotty.tools.dotc.ast.Trees$PackageDef # 22
*** error while checking ./T.class after phase frontend ***
Exception in thread "main" java.lang.AssertionError: assertion failed: found:    Foo[_](foo)
required: Foo[Foo[_]#<parameter A of class Foo>]


tree = foo
	at scala.Predef$.assert(Predef.scala:219)
	at dotty.tools.dotc.transform.TreeChecker$Checker.adapt(TreeChecker.scala:447)
	at dotty.tools.dotc.typer.ProtoTypes$FunProto.typedArg(ProtoTypes.scala:242)
	at dotty.tools.dotc.typer.Applications$ApplyToUntyped.typedArg(Applications.scala:642)
	at dotty.tools.dotc.typer.Applications$ApplyToUntyped.typedArg(Applications.scala:640)
	at dotty.tools.dotc.typer.Applications$Application.addTyped$1(Applications.scala:412)
	at dotty.tools.dotc.typer.Applications$Application.matchArgs(Applications.scala:451)
	at dotty.tools.dotc.typer.Applications$Application.init(Applications.scala:233)
	at dotty.tools.dotc.typer.Applications$TypedApply.<init>(Applications.scala:543)
	at dotty.tools.dotc.typer.Applications$ApplyToUntyped.<init>(Applications.scala:641)
	at dotty.tools.dotc.typer.Applications.simpleApply$1(Applications.scala:697)
	at dotty.tools.dotc.typer.Applications.$anonfun$typedApply$7(Applications.scala:722)
	at dotty.tools.dotc.typer.Typer.tryEither(Typer.scala:1809)
	at dotty.tools.dotc.typer.Applications.$anonfun$typedApply$1(Applications.scala:723)
	at dotty.tools.dotc.util.Stats$.track(Stats.scala:35)
	at dotty.tools.dotc.typer.Applications.realApply$1(Applications.scala:667)
	at dotty.tools.dotc.typer.Applications.typedApply(Applications.scala:767)
	at dotty.tools.dotc.typer.Applications.typedApply$(Applications.scala:665)
	at dotty.tools.dotc.typer.Typer.typedApply(Typer.scala:69)
	at dotty.tools.dotc.typer.Typer.typedUnnamed$1(Typer.scala:1678)
	at dotty.tools.dotc.typer.Typer.typedUnadapted(Typer.scala:1727)
	at dotty.tools.dotc.typer.ReTyper.typedUnadapted(ReTyper.scala:94)
	at dotty.tools.dotc.transform.TreeChecker$Checker.typedUnadapted(TreeChecker.scala:272)
	at dotty.tools.dotc.typer.Typer.$anonfun$typed$2(Typer.scala:1744)
	at dotty.tools.dotc.reporting.trace$.apply(trace.scala:23)
	at dotty.tools.dotc.typer.Typer.typed(Typer.scala:1740)
	at dotty.tools.dotc.transform.TreeChecker$Checker.typed(TreeChecker.scala:257)
	at dotty.tools.dotc.typer.Typer.traverse$1(Typer.scala:1777)
	at dotty.tools.dotc.typer.Typer.typedStats(Typer.scala:1789)
	at dotty.tools.dotc.transform.TreeChecker$Checker.typedStats(TreeChecker.scala:434)
	at dotty.tools.dotc.typer.Typer.typedBlockStats(Typer.scala:623)
	at dotty.tools.dotc.typer.Typer.$anonfun$typedBlock$1(Typer.scala:626)
	at dotty.tools.dotc.util.Stats$.track(Stats.scala:35)
	at dotty.tools.dotc.typer.Typer.typedBlock(Typer.scala:625)
...