6 files changed, 145 insertions, 2 deletions

diff --git a/test/files/neg/outer-ref-checks.check b/test/files/neg/outer-ref-checks.check
new file mode 100644
index 0000000000..bba7118d79
--- /dev/null
+++ b/test/files/neg/outer-ref-checks.check
@@ -0,0 +1,24 @@
+outer-ref-checks.scala:5: warning: The outer reference in this type test cannot be checked at run time.
+  final case class Inner(val s: String) // unchecked warning
+                   ^
+outer-ref-checks.scala:8: warning: The outer reference in this type test cannot be checked at run time.
+    case Inner(s) => // unchecked warning
+              ^
+outer-ref-checks.scala:18: warning: The outer reference in this type test cannot be checked at run time.
+    case Inner(s) => // unchecked warning
+              ^
+outer-ref-checks.scala:19: warning: The outer reference in this type test cannot be checked at run time.
+    case O.Inner(s) => // unchecked warning
+                ^
+outer-ref-checks.scala:41: warning: The outer reference in this type test cannot be checked at run time.
+    case Inner(s) => // unchecked warning
+              ^
+outer-ref-checks.scala:46: warning: The outer reference in this type test cannot be checked at run time.
+    case _: Inner => // unchecked warning
+          ^
+outer-ref-checks.scala:56: warning: The outer reference in this type test cannot be checked at run time.
+    case _: (Inner @uncheckedVariance) => // unchecked warning
+          ^
+error: No warnings can be incurred under -Xfatal-warnings.
+7 warnings found
+one error found
diff --git a/test/files/neg/outer-ref-checks.flags b/test/files/neg/outer-ref-checks.flags
new file mode 100644
index 0000000000..464cc20ea6
--- /dev/null
+++ b/test/files/neg/outer-ref-checks.flags
@@ -0,0 +1 @@
+-Xfatal-warnings -unchecked
\ No newline at end of file
diff --git a/test/files/neg/outer-ref-checks.scala b/test/files/neg/outer-ref-checks.scala
new file mode 100644
index 0000000000..35983fe92b
--- /dev/null
+++ b/test/files/neg/outer-ref-checks.scala
@@ -0,0 +1,106 @@
+import scala.annotation.unchecked.uncheckedVariance
+
+class Outer {
+  // A final class gets no outer ref, so we expect to see warnings where an outer ref check should be performed
+  final case class Inner(val s: String) // unchecked warning
+
+  def belongs(a: Any): Unit = a match {
+    case Inner(s) => // unchecked warning
+    case _ =>
+  }
+
+  def belongsStaticSameOuter(a: Inner): Unit = a match {
+    case Inner(s) => // no need for outer check
+    // match is exhaustive, no default case needed
+  }
+
+  def belongsOtherOuter(a: Outer#Inner): Unit = a match {
+    case Inner(s) => // unchecked warning
+    case O.Inner(s) => // unchecked warning
+    case _ =>
+  }
+}
+
+object O extends Outer {
+  def belongsStaticSameOuter2(a: Inner): Unit = a match {
+    case Inner(s) => // no need for outer check
+    // match is exhaustive, no default case needed
+  }
+
+  def belongsStaticSameOuter3(a: Inner): Unit = a match {
+    case _: Inner => // no need for outer check
+    // match is exhaustive, no default case needed
+  }
+
+  def belongsStaticSameOuter4(a: Inner): Unit = a match {
+    case _: (Inner @uncheckedVariance) => // no need for outer check
+    // match is exhaustive, no default case needed
+  }
+
+  def belongsOtherOuter2(a: Outer#Inner): Unit = a match {
+    case Inner(s) => // unchecked warning
+    case _ =>
+  }
+
+  def belongsOtherOuter3(a: Outer#Inner): Unit = a match {
+    case _: Inner => // unchecked warning
+    case _ =>
+  }
+
+  def belongsOtherOuter4(a: Outer#Inner): Unit = a match {
+    case _: (Inner @unchecked) => // warning supressed
+    case _ =>
+  }
+
+  def belongsOtherOuter5(a: Outer#Inner): Unit = a match {
+    case _: (Inner @uncheckedVariance) => // unchecked warning
+    case _ =>
+  }
+
+  def nested: Unit = {
+    final case class I(s: String)
+
+    def check1(a: Any): Unit = a match {
+      case I(s) => // no need for outer check
+      case _ =>
+    }
+
+    def check2(a: I): Unit = a match {
+      case I(s) => // no need for outer check
+      // match is exhaustive, no default case needed
+    }
+  }
+}
+
+class O2 {
+  def nested: Unit = {
+    final case class I(s: String)
+
+    def check1(a: Any): Unit = a match {
+      case I(s) => // no need for outer check (is this correct?)
+      case _ =>
+    }
+
+    def check2(a: I): Unit = a match {
+      case I(s) => // no need for outer check (is this correct?)
+      // match is exhaustive, no default case needed
+    }
+  }
+}
+
+package p {
+  object T {
+    case class C(x: Int)
+  }
+}
+
+object U {
+  val T = p.T
+}
+
+class Test {
+  def m(a: Any) = a match {
+    case U.T.C(1) => 1  // used to warn
+    case _ => 1
+  }
+}
diff --git a/test/files/neg/t7171.check b/test/files/neg/t7171.check
index ecd768afda..2de9151483 100644
--- a/test/files/neg/t7171.check
+++ b/test/files/neg/t7171.check
@@ -1,6 +1,9 @@
 t7171.scala:2: warning: The outer reference in this type test cannot be checked at run time.
   final case class A()
                    ^
+t7171.scala:9: warning: The outer reference in this type test cannot be checked at run time.
+    case _: A => true; case _ => false
+          ^
 error: No warnings can be incurred under -Xfatal-warnings.
-one warning found
+two warnings found
 one error found
diff --git a/test/files/neg/t7171b.check b/test/files/neg/t7171b.check
index bf695afea7..6b05b6fa63 100644
--- a/test/files/neg/t7171b.check
+++ b/test/files/neg/t7171b.check
@@ -1,6 +1,12 @@
 t7171b.scala:2: warning: The outer reference in this type test cannot be checked at run time.
   final case class A()
                    ^
+t7171b.scala:8: warning: The outer reference in this type test cannot be checked at run time.
+    case _: A => true; case _ => false
+          ^
+t7171b.scala:13: warning: The outer reference in this type test cannot be checked at run time.
+    case _: A => true; case _ => false
+          ^
 error: No warnings can be incurred under -Xfatal-warnings.
-one warning found
+three warnings found
 one error found
diff --git a/test/files/run/t7171.check b/test/files/run/t7171.check
index d826f6cb94..5454142882 100644
--- a/test/files/run/t7171.check
+++ b/test/files/run/t7171.check
@@ -1,3 +1,6 @@
 t7171.scala:2: warning: The outer reference in this type test cannot be checked at run time.
   final case class A()
                    ^
+t7171.scala:9: warning: The outer reference in this type test cannot be checked at run time.
+    case _: A => true; case _ => false
+          ^