1 files changed, 43 insertions, 0 deletions
diff --git a/tests/pos/t573.scala b/tests/pos/t573.scala
new file mode 100644
index 000000000..1aadb446c
--- /dev/null
+++ b/tests/pos/t573.scala
@@ -0,0 +1,43 @@
+package lampion.collections;
+
+object DirX {
+  abstract class Dir {
+    def reverse : Dir;
+  }
+  object BEFORE extends Dir {
+    def reverse = AFTER;
+  }
+  object AFTER  extends Dir {
+    def reverse = BEFORE;
+  }
+}
+
+import DirX._;
+
+abstract class Linked {
+  type Node <: Node0;
+
+  abstract class Node0 {
+    self: Node =>
+
+    var next : Node = _;
+    var prev : Node = _;
+
+    def get(dir : Dir) = if (dir == BEFORE) prev; else next;
+    private def set(dir : Dir, node : Node) =
+      if (dir == BEFORE) prev = node; else next = node;
+
+    def link(dir : Dir, node : Node) = {
+      assert(get(dir) == null);
+      assert(node.get(dir.reverse) == null);
+      set(dir, node);
+      node.set(dir.reverse, self);
+    }
+
+
+    def end(dir : Dir) : Node = {
+      if (get(dir) == null) this;
+      else get(dir).end(dir);
+    }
+  }
+}