Fix issue with higher-order type params.

I think I found an issue underlying more than one bit of sketchy
behavior amongst CC[_] and friends.

Plus, I managed to initialize TypeConstraints with the bounds of the
originating type parameter. I feel like that should cause something
nifty to happen somewhere, but I have seen neither confetti nor lasers
in greater quantities than I usually do. Will keep my remaining eye out.

Closes SI-5359, review by @moors.

1 files changed, 17 insertions, 0 deletions

diff --git a/test/files/pos/t5359.scala b/test/files/pos/t5359.scala
new file mode 100644
index 0000000000..c22b2b1c76
--- /dev/null
+++ b/test/files/pos/t5359.scala
@@ -0,0 +1,17 @@
+// /scala/trac/5359/a.scala
+// Thu Jan  5 13:31:05 PST 2012
+
+object test {
+  trait Step[F[_]] {
+    // crash: typeConstructor inapplicable for <none>
+    this match {
+      case S1() =>
+    }
+  }
+  case class S1[F[_]]() extends Step[F]
+
+  // okay
+  (null: Step[Option]) match {
+    case S1() =>
+  }
+}