A wholesale reversion of the pattern matcher to...

A wholesale reversion of the pattern matcher to r21939, motivated by
the appearance of #3578. Closes #3578, reopens #2800, #3050. Review by
moors. (I can't keep saying "no review" when every move I make in here
seems to break something.)

3 files changed, 31 insertions, 19 deletions

diff --git a/test/files/neg/array-not-seq.check b/test/files/neg/array-not-seq.check
index bd72bb4e13..c16ecdad72 100644
--- a/test/files/neg/array-not-seq.check
+++ b/test/files/neg/array-not-seq.check
@@ -1,16 +1,7 @@
 array-not-seq.scala:2: error: An Array will no longer match as Seq[_].
   def f1(x: Any) = x.isInstanceOf[Seq[_]]
                                  ^
-array-not-seq.scala:4: error: An Array will no longer match as Seq[_].
-    case _: Seq[_]  => true
-          ^
 error: An Array will no longer match as Seq[_].
-array-not-seq.scala:16: error: An Array will no longer match as Seq[_].
-    case (Some(_: Seq[_]), Nil, _)        => 1
-                ^
 error: An Array will no longer match as Seq[_].
-array-not-seq.scala:15: error: An Array will no longer match as Seq[_].
-  def f5(x1: Any, x2: Any, x3: AnyRef) = (x1, x2, x3) match {
-                                              ^
 error: An Array will no longer match as Seq[_].
-7 errors found
+four errors found
diff --git a/test/files/pos/bug3578.scala b/test/files/pos/bug3578.scala
new file mode 100644
index 0000000000..d984118208
--- /dev/null
+++ b/test/files/pos/bug3578.scala
@@ -0,0 +1,30 @@
+object Test {
+  sealed abstract class JValue {
+    def ++(other: JValue) = {
+      def append(value1: JValue, value2: JValue): JValue = (value1, value2) match {
+	case (JNothing, x) => x
+	case (x, JNothing) => x
+	case (JObject(xs), x: JField) => JObject(xs ::: List(x))
+	case (x: JField, JObject(xs)) => JObject(x :: xs)
+	case (JArray(xs), JArray(ys)) => JArray(xs ::: ys)
+	case (JArray(xs), v: JValue) => JArray(xs ::: List(v))
+	case (v: JValue, JArray(xs)) => JArray(v :: xs)
+	case (f1: JField, f2: JField) => JObject(f1 :: f2 :: Nil)
+	case (JField(n, v1), v2: JValue) => JField(n, append(v1, v2))
+	case (x, y) => JArray(x :: y :: Nil)
+      }
+      append(this, other)
+    }
+  }
+
+  case object JNothing extends JValue
+  case object JNull extends JValue
+  case class JString(s: String) extends JValue
+  case class JDouble(num: Double) extends JValue
+  case class JInt(num: BigInt) extends JValue
+  case class JBool(value: Boolean) extends JValue
+  case class JField(name: String, value: JValue) extends JValue
+  case class JObject(obj: List[JField]) extends JValue
+  case class JArray(arr: List[JValue]) extends JValue
+}
+
diff --git a/test/files/run/bug3050.scala b/test/files/run/bug3050.scala
deleted file mode 100644
index aaec99ec14..0000000000
--- a/test/files/run/bug3050.scala
+++ /dev/null
@@ -1,9 +0,0 @@
-object Test {
-  def main(args: Array[String]): Unit = {
-    val x =
-      try { ("": Any) match { case List(_*) => true } }
-      catch { case _ => false }
-
-    assert(x == false)
-  }
-}