Merge pull request #8063 from dotty-staging/fix-#8056

Fix #8056: Handle and/or types in translateParameterized

Author: anatoliykmetyuk

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

@@ -455,7 +455,10 @@ class TypeApplications(val self: Type) extends AnyVal {
       self.derivedExprType(tp.translateParameterized(from, to))
     case _ =>
       if (self.derivesFrom(from)) {
-        val arg = self.baseType(from).argInfos.head
+        def elemType(tp: Type): Type = tp match
+          case tp: AndOrType => tp.derivedAndOrType(elemType(tp.tp1), elemType(tp.tp2))
+          case _ => tp.baseType(from).argInfos.head
+        val arg = elemType(self)
         val arg1 = if (wildcardArg) TypeBounds.upper(arg) else arg
         to.typeRef.appliedTo(arg1)
       }

tests/pos/i8056.scala

@@ -0,0 +1,5 @@
+object O{
+  def m(x: Any*) = ()
+  def n(l: List[Int] | List[String]): Unit = m(l: _*)
+  def n2(l: List[Int] & List[String]): Unit = m(l: _*)
+}