Only final lazy vals can be paths.

Reason: They might be overridden by other lazy vals
that are not realizable, and therefore risk creating
bad bounds.

1 files changed, 29 insertions, 0 deletions

diff --git a/tests/neg/i1050a.scala b/tests/neg/i1050a.scala
new file mode 100644
index 000000000..47e2f0c59
--- /dev/null
+++ b/tests/neg/i1050a.scala
@@ -0,0 +1,29 @@
+object Tiark1 {
+    trait A { type L <: Nothing }
+    trait B { type L >: Any}
+    trait U {
+      val p: B
+      def brand(x: Any): p.L = x // error: not final
+    }
+    trait V extends U {
+      lazy val p: A & B = ???
+    }
+    val v = new V {}
+    v.brand("boom!")
+}
+object Tiark2 {
+    trait A { type L <: Nothing }
+    trait B { type L >: Any}
+    trait U {
+      type X <: B
+      val p: X
+      def brand(x: Any): p.L = x // error: not final
+    }
+    trait V extends U {
+      type X = B & A
+      lazy val p: X = ???
+    }
+    val v = new V {}
+    v.brand("boom!"): Nothing
+}
+