From 1c900a35155c0b92fd3b96794ffb55c0b0c03d9c Mon Sep 17 00:00:00 2001
From: Aleksander Boruch-Gruszecki <aleksander.boruchgruszecki@gmail.com>
Date: Thu, 13 Apr 2017 22:17:43 +0200
Subject: Recurse into refined type when exposing members

---
 .../dotty/tools/dotc/transform/patmat/Space.scala  |  7 +++++-
 tests/patmat/i2253.check                           |  3 +++
 tests/patmat/i2253.scala                           | 29 +++++++++++++++++++---
 3 files changed, 35 insertions(+), 4 deletions(-)
 create mode 100644 tests/patmat/i2253.check

diff --git a/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala b/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
index fe2983896..53518ec9c 100644
--- a/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
+++ b/compiler/src/dotty/tools/dotc/transform/patmat/Space.scala
@@ -537,7 +537,12 @@ class SpaceEngine(implicit ctx: Context) extends SpaceLogic {
               tp.refinedName,
               tpb.derivedTypeBounds(follow(lo, false), follow(hi, true))
             )
-          case tp => tp
+          case _ =>
+            tp.derivedRefinedType(
+              expose(tp.parent),
+              tp.refinedName,
+              tp.refinedInfo
+            )
         }
       case _ => tp
     }
diff --git a/tests/patmat/i2253.check b/tests/patmat/i2253.check
new file mode 100644
index 000000000..5c86a1ef8
--- /dev/null
+++ b/tests/patmat/i2253.check
@@ -0,0 +1,3 @@
+27: Pattern Match Exhaustivity: HasIntXIntM, HasIntXStringM
+28: Pattern Match Exhaustivity: HasIntXIntM
+29: Pattern Match Exhaustivity: HasIntXIntM
diff --git a/tests/patmat/i2253.scala b/tests/patmat/i2253.scala
index 8394a86df..0344a6a5d 100644
--- a/tests/patmat/i2253.scala
+++ b/tests/patmat/i2253.scala
@@ -1,7 +1,30 @@
 sealed trait S
-object O extends S
+
+object BodylessObject extends S
+
+object HasIntM extends S {
+  type M = Int
+}
+
+object HasStringXStringM extends S {
+  type M = String
+  val x: String = ""
+}
+
+object HasIntXStringM extends S {
+  type M = String
+  val x: Int = 0
+}
+
+object HasIntXIntM extends S {
+  type M = Int
+  val x: Int = 0
+}
+
 trait T
 
 class Test {
-  def m(s: S { val x: Int }) = s match { case _: T => ; }
-}
\ No newline at end of file
+  def onlyIntX(s: S { val x: Int }) = s match { case _: T => ; }
+  def exposeAlias1[I <: Int](s: S { type M = I; val x: Int }) = s match { case _: T => ; }
+  def exposeAlias2[I <: Int](s: S { val x: Int; type M = I }) = s match { case _: T => ; }
+}
-- 
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