Merge pull request #4021 from retronym/ticket/8869

SI-8869 Prevent ill-kindedness in type lambdas

2 files changed, 17 insertions, 0 deletions

diff --git a/test/files/neg/t8869.check b/test/files/neg/t8869.check
new file mode 100644
index 0000000000..40b8570f9f
--- /dev/null
+++ b/test/files/neg/t8869.check
@@ -0,0 +1,7 @@
+t8869.scala:5: error: class Option takes type parameters
+  def value: TC[({type l1[x] = Option})#l1] = ??? // error not reported!
+                               ^
+t8869.scala:7: error: class Option takes type parameters
+  type l2[x] = Option // error correctly reported
+               ^
+two errors found
diff --git a/test/files/neg/t8869.scala b/test/files/neg/t8869.scala
new file mode 100644
index 0000000000..0c7f0c9451
--- /dev/null
+++ b/test/files/neg/t8869.scala
@@ -0,0 +1,10 @@
+class TC[T[_]] {
+  def identity[A](a: T[A]): T[A] = a
+}
+object Test {
+  def value: TC[({type l1[x] = Option})#l1] = ??? // error not reported!
+
+  type l2[x] = Option // error correctly reported
+  def value1: TC[l2] = ???
+}
+