SI-10194: Fix abstract type resolution for overloaded HOFs

Types in the applicable overload alternatives need to be seen from
the respective owners of the individual alternative, not from the
target’s owner (which can be a subtype of the types that define the
methods).

1 files changed, 15 insertions, 0 deletions

diff --git a/test/files/pos/overloaded_ho_fun.scala b/test/files/pos/overloaded_ho_fun.scala
index 2699ad35f8..17176715f0 100644
--- a/test/files/pos/overloaded_ho_fun.scala
+++ b/test/files/pos/overloaded_ho_fun.scala
@@ -49,3 +49,18 @@ object sorting {
 //   def andThen[C](g: Bijection[B, C]): Bijection[A, C] = ???
 //   def compose[T](g: Bijection[T, A]) = g andThen this
 // }
+
+object SI10194 {
+  trait X[A] {
+    def map[B](f: A => B): Unit
+  }
+
+  trait Y[A] extends X[A] {
+    def map[B](f: A => B)(implicit ordering: Ordering[B]): Unit
+  }
+
+  trait Z[A] extends Y[A]
+
+  (null: Y[Int]).map(x => x.toString) // compiled
+  (null: Z[Int]).map(x => x.toString) // didn't compile
+}