1 files changed, 40 insertions, 0 deletions
diff --git a/test/files/neg/t6675b.scala b/test/files/neg/t6675b.scala
new file mode 100644
index 0000000000..c86c9c3955
--- /dev/null
+++ b/test/files/neg/t6675b.scala
@@ -0,0 +1,40 @@
+object LeftOrRight {
+  def unapply[A](value: Either[A, A]): Option[A] = value match {
+    case scala.Left(x)  => Some(x)
+    case scala.Right(x) => Some(x)
+  }
+}
+
+object NativelyTwo {
+  def unapply[A](value: Either[A, A]): Option[(A, A)] = value match {
+    case scala.Left(x)  => Some(x -> x)
+    case scala.Right(x) => Some(x -> x)
+  }
+}
+
+
+class A {
+  def f1 = (Left((0, 0)): Either[(Int, Int), (Int, Int)]) match { case LeftOrRight(a) => a  }          // warn
+  def f2 = (Left((0, 0)): Either[(Int, Int), (Int, Int)]) match { case LeftOrRight((a, b)) => a  }     // no warn
+  def f3 = (Left((0, 0)): Either[(Int, Int), (Int, Int)]) match { case LeftOrRight((a, b, c)) => a  }  // fail
+}
+
+class B {
+  def f1[A](x: A) = (Left(x): Either[A, A])                match { case LeftOrRight(a) => a  }          // no warn
+  def f2[A](x: A) = (Left(x -> x): Either[(A, A), (A, A)]) match { case LeftOrRight(a) => a  }          // warn
+  def f3[A](x: A) = (Left(x -> x): Either[(A, A), (A, A)]) match { case LeftOrRight((a, b)) => a  }     // no warn
+  def f4[A](x: A) = (Left(x -> x): Either[(A, A), (A, A)]) match { case LeftOrRight((a, b, c)) => a  }  // fail
+}
+
+class C {
+  def f1 = (Left((0, 0)): Either[(Int, Int), (Int, Int)]) match { case NativelyTwo(a) => a  }          // warn
+  def f2 = (Left((0, 0)): Either[(Int, Int), (Int, Int)]) match { case NativelyTwo((a, b)) => a  }     // no warn
+  def f3 = (Left((0, 0)): Either[(Int, Int), (Int, Int)]) match { case NativelyTwo((a, b, c)) => a  }  // fail
+}
+
+class D {
+  def f1[A](x: A) = (Left(x): Either[A, A])                match { case NativelyTwo(a) => a  }          // warn
+  def f2[A](x: A) = (Left(x -> x): Either[(A, A), (A, A)]) match { case NativelyTwo(a) => a  }          // warn
+  def f3[A](x: A) = (Left(x -> x): Either[(A, A), (A, A)]) match { case NativelyTwo((a, b)) => a  }     // no warn
+  def f4[A](x: A) = (Left(x -> x): Either[(A, A), (A, A)]) match { case NativelyTwo((a, b, c)) => a  }  // fail
+}