Working my way through pattern matcher sequence...

Working my way through pattern matcher sequence issues mostly caused by
the special handling of Lists. Also deleting all kinds of useless or
almost useless code which is presently only clutter.

Closes #2756, #2800, #3050, #3530, #3972, no review.

6 files changed, 105 insertions, 7 deletions

diff --git a/test/files/pos/bug3972.scala b/test/files/pos/bug3972.scala
new file mode 100644
index 0000000000..5dfc10fcef
--- /dev/null
+++ b/test/files/pos/bug3972.scala
@@ -0,0 +1,11 @@
+object CompilerCrash {
+  def main(args: Array[String]) {
+    args match {
+      case Array("a", a @ _*) => { } // The code compiles fine if this line is commented out or "@ _*" is deleted or this line is swapped for the next line
+      case Array("b") => { } // The code compiles fine if this line is commented out
+      case Array("c", c) => {
+        0 // The code compiles fine if this line is commented out
+      }
+    }
+  }
+}
diff --git a/test/files/run/bug2800.check b/test/files/run/bug2800.check
new file mode 100644
index 0000000000..546ee52413
--- /dev/null
+++ b/test/files/run/bug2800.check
@@ -0,0 +1,14 @@
+false
+false
+List()
+false
+false
+false
+false
+Vector(1)
+false
+false
+true
+false
+false
+false
diff --git a/test/files/run/bug2800.scala b/test/files/run/bug2800.scala
new file mode 100644
index 0000000000..84d1de0507
--- /dev/null
+++ b/test/files/run/bug2800.scala
@@ -0,0 +1,36 @@
+object Test {
+  def f1 = ("": Any) match { case List(x @ _*) => x ; case _ => false }
+  def f2 = (5: Any) match { case List(x @ _*) => x ; case _ => false }
+  def f3 = (Nil: Any) match { case List(x @ _*) => x ; case _ => false }
+  def f4 = (Array(1): Any) match { case List(x @ _*) => x ; case _ => false }
+
+  def f5 = ("": Any) match { case Array(x @ _*) => x ; case _ => false }
+  def f6 = (5: Any) match { case Array(x @ _*) => x ; case _ => false }
+  def f7 = (Nil: Any) match { case Array(x @ _*) => x ; case _ => false }
+  def f8 = (Array(1): Any) match { case Array(x @ _*) => x ; case _ => false }
+
+  def f9 = ("": Any) match { case x @ List(_*) => x ; case _ => false }
+  def f10 = ("": Any) match { case List(_*) => true ; case _ => false }
+  def f11 = (Nil: Any) match { case List(_*) => true ; case _ => false }
+  def f12 = ("": Any) match { case x @ Array(_*) => x ; case _ => false }
+  def f13 = ("": Any) match { case Array(_*) => true ; case _ => false }
+  def f14 = (Nil: Any) match { case Array(_*) => true ; case _ => false }
+
+
+  def main(args: Array[String]): Unit = {
+    println(f1)
+    println(f2)
+    println(f3)
+    println(f4)
+    println(f5)
+    println(f6)
+    println(f7)
+    println(f8)
+    println(f9)
+    println(f10)
+    println(f11)
+    println(f12)
+    println(f13)
+    println(f14)
+  }
+}
diff --git a/test/pending/run/bug3050.scala b/test/files/run/bug3050.scala
index aaec99ec14..d1f3f13bec 100644
--- a/test/pending/run/bug3050.scala
+++ b/test/files/run/bug3050.scala
@@ -4,6 +4,6 @@ object Test {
       try { ("": Any) match { case List(_*) => true } }
       catch { case _ => false }
 
-    assert(x == false)
+    assert(!x)
   }
 }
diff --git a/test/files/run/bug3530.check b/test/files/run/bug3530.check
index 633c15d9d7..1f906680e9 100644
--- a/test/files/run/bug3530.check
+++ b/test/files/run/bug3530.check
@@ -1 +1,12 @@
-Some List
+two
+three
+list: 4
+list: 0
+list: 5
+not a list
+
+two
+three
+list: 4
+list: 0
+list: 5
diff --git a/test/files/run/bug3530.scala b/test/files/run/bug3530.scala
index f2c0034691..f6f7fb4229 100644
--- a/test/files/run/bug3530.scala
+++ b/test/files/run/bug3530.scala
@@ -1,9 +1,35 @@
 object Test {
+  def f(x: Any) = println(x match {
+    case List(_, _)    => "two"
+    case List(_, _, _) => "three"
+    case xs @ List(_*) => "list: " + xs.length
+    case _             => "not a list"
+  })
+
+  def f2[T](x: List[T]) = println(x match {
+    case List(_, _)       => "two"
+    case List(_, _, _)    => "three"
+    case List(xs @ _*)    => "list: " + xs.length
+    // bug: the default case is marked unreachable
+    // case _                => "not a list"
+  })
+
   def main(args: Array[String]) {
-    val list = List(1,2,3)
-    list match {
-      case List(_, _) => println("List with two elements")
-      case List(_*) => println("Some List")
-    }
+    f(List(1, 2))
+    f(List('a', 'b', 'c'))
+    f(List('a', 'b', 'c', 'd'))
+    f(Nil)
+    f(List(1,2,3,4,5))
+    f(null)
+
+    println
+
+    f2(List(1, 2))
+    f2(List('a', 'b', 'c'))
+    f2(List('a', 'b', 'c', 'd'))
+    f2(Nil)
+    f2(List(1,2,3,4,5))
+    // bug: this NPEs on xs.length
+    // f2(null)
   }
 }
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