Closes t5399. Review by adriaanm

2 files changed, 46 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index e643a91da7..b0f6e44e88 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -2237,7 +2237,7 @@ trait Typers extends Modes with Adaptations with Taggings {
     // takes untyped sub-trees of a match and type checks them
     def typedMatch(selector: Tree, cases: List[CaseDef], mode: Int, pt: Type, tree: Tree = EmptyTree): Match = {
       val selector1  = checkDead(typed(selector, EXPRmode | BYVALmode, WildcardType))
-      val selectorTp = packCaptured(selector1.tpe.widen)
+      val selectorTp = packCaptured(selector1.tpe.widen).skolemizeExistential(context.owner, selector)
       val casesTyped = typedCases(cases, selectorTp, pt)
 
       val (resTp, needAdapt) =
diff --git a/test/files/pos/t5399.scala b/test/files/pos/t5399.scala
new file mode 100644
index 0000000000..ebae7dbd9e
--- /dev/null
+++ b/test/files/pos/t5399.scala
@@ -0,0 +1,45 @@
+class Test {
+  class A[T]
+  class B[T](val a: A[T])
+
+  case class CaseClass[T](x: T)
+
+  def break(existB: B[_]) =
+    CaseClass(existB.a) match { case CaseClass(_) => }
+}
+
+class Foo {
+  trait Init[T]
+  class ScopedKey[T] extends Init[T]
+
+  trait Setting[T] {
+    val key: ScopedKey[T]
+  }
+
+  case class ScopedKey1[T](val foo: Init[T]) extends ScopedKey[T]
+
+  val scalaHome: Setting[Option[String]] = null
+  val scalaVersion: Setting[String] = null
+
+  def testPatternMatch(s: Setting[_]) {
+    s.key match {
+      case ScopedKey1(scalaHome.key | scalaVersion.key) => ()
+    }
+  }
+}
+
+class Test2 {
+  type AnyCyclic = Execute[Task]#CyclicException[_]
+
+  trait Task[T]
+
+  trait Execute[A[_] <: AnyRef] {
+    class CyclicException[T](val caller: A[T], val target: A[T])
+  }
+
+  def convertCyclic(c: AnyCyclic): String =
+    (c.caller, c.target) match {
+      case (caller: Task[_], target: Task[_]) => "bazinga!"
+    }
+}
+