Clean tests

Author: noti0na1

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

@@ -114,7 +114,7 @@ object JavaNullInterop {
           // This is because `setNames(null)` passes as argument a single-element array containing the value `null`,
           // and not a `null` array.
           || !ctx.flexibleTypes && tp.isRef(defn.RepeatedParamClass)
-        case _ => true
+        case _ => false
       }))
 
     override def apply(tp: Type): Type = tp match {

compiler/src/dotty/tools/dotc/typer/Applications.scala

@@ -645,14 +645,15 @@ trait Applications extends Compatibility {
               missingArg(n)
           }
 
-          if (formal.isRepeatedParam)
+          val formal1 = formal.stripFlexible
+          if (formal1.isRepeatedParam)
             args match {
               case arg :: Nil if isVarArg(arg) =>
                 addTyped(arg)
               case (arg @ Typed(Literal(Constant(null)), _)) :: Nil if ctx.isAfterTyper =>
                 addTyped(arg)
               case _ =>
-                val elemFormal = formal.widenExpr.argTypesLo.head
+                val elemFormal = formal1.widenExpr.argTypesLo.head
                 val typedArgs =
                   harmonic(harmonizeArgs, elemFormal) {
                     args.map { arg =>

tests/explicit-nulls/flexible-types/common/interop-propagate.scala

@@ -3,16 +3,16 @@
 
   // Test that type mapping works with flexible types.
   val ll: ArrayList[ArrayList[ArrayList[String]]] = new ArrayList[ArrayList[ArrayList[String]]]
-  val level1: ArrayList[ArrayList[String]] = ll.get(0)
-  val level2: ArrayList[String] = ll.get(0).get(0)
-  val level3: String = ll.get(0).get(0).get(0)
+  val level1: ArrayList[ArrayList[String]] = ll.get(0) // error
+  val level2: ArrayList[String] = ll.get(0).get(0) // error
+  val level3: String = ll.get(0).get(0).get(0)  // error
 
   val lb = new ArrayList[ArrayList[ArrayList[String]]]
   val levelA = lb.get(0)
-  val levelB = lb.get(0).get(0)
-  val levelC = lb.get(0).get(0).get(0)
+  val levelB = lb.get(0).get(0)  // error
+  val levelC = lb.get(0).get(0).get(0)  // error
 
-  val x = levelA.get(0)
+  val x = levelA.get(0)  // error
   val y = levelB.get(0)
-  val z: String = levelA.get(0).get(0)
+  val z: String = levelA.get(0).get(0)  // error
 }

tests/explicit-nulls/flexible-types/common/java-call/S.scala

@@ -10,7 +10,7 @@ val s1n: String | Null = j.f1()
 
 val i1: Int = j.f2()
 
-val k: jj.K = jj.f3()
+val k: jj.K = jj.f3() // error // error
 
 val s2: String = j.g1[String]()  // error
 

tests/explicit-nulls/flexible-types/common/unsafe-match-null.scala

@@ -0,0 +1,5 @@
+def test1 =
+  val s: String = ???
+  s.trim() match
+    case _: String =>
+    case null =>