Merge pull request #2222 from dotty-staging/fix/wildcard-apply

Fix #2219: Fix type applications on WildcardType

Author: smarter

compiler/src/dotty/tools/dotc/core/TypeApplications.scala

@@ -429,7 +429,7 @@ class TypeApplications(val self: Type) extends AnyVal {
       case dealiased: LazyRef =>
         LazyRef(() => dealiased.ref.appliedTo(args))
       case dealiased: WildcardType =>
-        dealiased
+        WildcardType(dealiased.optBounds.appliedTo(args).bounds)
       case dealiased: TypeRef if dealiased.symbol == defn.NothingClass =>
         dealiased
       case _ if typParams.isEmpty || typParams.head.isInstanceOf[LambdaParam] =>

tests/pos/i2219.scala

@@ -0,0 +1,7 @@
+object Test {
+  type Inv[T[_]] = T[_]
+
+  class Hi[T[_]](x: Inv[T]) {
+    def foo[T[_]](value: Inv[T] = x) = {}
+  }
+}