Merge pull request #2157 from retronym/ticket/7171

SI-7171 Consider prefix when assessing type finality.

1 files changed, 22 insertions, 0 deletions

diff --git a/test/files/run/t7171.scala b/test/files/run/t7171.scala
new file mode 100644
index 0000000000..97585b9860
--- /dev/null
+++ b/test/files/run/t7171.scala
@@ -0,0 +1,22 @@
+trait T {
+  final case class A()
+
+  // Was:
+  // error: scrutinee is incompatible with pattern type;
+  // found   : T.this.A
+  // required: T#A
+  def foo(a: T#A) = a match {
+    case _: A => true; case _ => false
+  }
+}
+
+object Test extends App {
+  val t1 = new T {}
+  val t2 = new T {}
+  val a1 = new t1.A()
+  val a2 = new t1.A()
+  assert(t1.foo(a1))
+  // as noted in the unchecked warning (tested in the corresponding neg test),
+  // the outer pointer isn't checked
+  assert(t1.foo(a2))
+}