Merge pull request #3178 from retronym/ticket/7872

SI-7872 Plug a variance exploit in refinement types

1 files changed, 10 insertions, 0 deletions

diff --git a/src/reflect/scala/reflect/internal/Variances.scala b/src/reflect/scala/reflect/internal/Variances.scala
index 5280467055..cd09e83cd3 100644
--- a/src/reflect/scala/reflect/internal/Variances.scala
+++ b/src/reflect/scala/reflect/internal/Variances.scala
@@ -162,6 +162,16 @@ trait Variances {
           traverseTreess(vparamss)
         case Template(_, _, _) =>
           super.traverse(tree)
+        case CompoundTypeTree(templ) =>
+          super.traverse(tree)
+
+        // SI-7872 These two cases make sure we don't miss variance exploits
+        // in originals, e.g. in `foo[({type l[+a] = List[a]})#l]`
+        case tt @ TypeTree() if tt.original != null =>
+          super.traverse(tt.original)
+        case tt : TypTree =>
+          super.traverse(tt)
+
         case _ =>
       }
     }