From cf37737f56db7bc2f7429f78328dc5eea1716356 Mon Sep 17 00:00:00 2001
From: liu fengyun <liu@fengy.me>
Date: Thu, 13 Apr 2017 14:32:05 +0200
Subject: fix #2253: avoid exception with refinement types

---
 compiler/src/dotty/tools/dotc/transform/patmat/Space.scala | 1 +
 tests/patmat/i2253.scala                                   | 7 +++++++
 2 files changed, 8 insertions(+)
 create mode 100644 tests/patmat/i2253.scala

diff --git a/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala b/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
index 229545a57..fe2983896 100644
--- a/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
+++ b/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
@@ -537,6 +537,7 @@ class SpaceEngine(implicit ctx: Context) extends SpaceLogic {
               tp.refinedName,
               tpb.derivedTypeBounds(follow(lo, false), follow(hi, true))
             )
+          case tp => tp
         }
       case _ => tp
     }
diff --git a/tests/patmat/i2253.scala b/tests/patmat/i2253.scala
new file mode 100644
index 000000000..8394a86df
--- /dev/null
+++ b/tests/patmat/i2253.scala
@@ -0,0 +1,7 @@
+sealed trait S
+object O extends S
+trait T
+
+class Test {
+  def m(s: S { val x: Int }) = s match { case _: T => ; }
+}
\ No newline at end of file
-- 
cgit v1.2.3