Merge pull request #15451 from dotty-staging/fix-15448

Fix isStructuralTermSelectOrApply

Author: KacperFKorban

compiler/src/dotty/tools/dotc/ast/TreeInfo.scala

@@ -869,7 +869,7 @@ trait TypedTreeInfo extends TreeInfo[Type] { self: Trees.Instance[Type] =>
         case RefinedType(parent, rname, rinfo) =>
           rname == tree.name || hasRefinement(parent)
         case tp: TypeProxy =>
-          hasRefinement(tp.underlying)
+          hasRefinement(tp.superType)
         case tp: AndType =>
           hasRefinement(tp.tp1) || hasRefinement(tp.tp2)
         case tp: OrType =>

tests/neg/i15448.scala

@@ -0,0 +1,11 @@
+object Minimized:
+  type Pointer[S <: Int] <: S
+
+  type Break = Int {
+    def boom: Unit
+  }
+
+  def test = {
+    val ptrBreak: Pointer[Break] = ???
+    ptrBreak.boom // error Required: Selectable, was boom crashes the compiler
+  }

tests/pos/i15448.scala

@@ -0,0 +1,21 @@
+object SelectableBreaks1 {
+  object opaques {
+    opaque type Pointer[S] <: S = S
+    object Pointer {
+      implicit class PointerSelectable[S](private val f: Pointer[S]) extends Selectable {
+        def selectDynamic(name: String): Any = ???
+        def applyDynamic(name: String)(): Any = ???
+      }
+    }
+  }
+  import opaques.*
+
+  type Break = AnyRef {
+    def boom(): Nothing
+  }
+
+  def makeBreak(): Pointer[Break] = ???
+
+  makeBreak().boom()
+}
+