Add more tests

Author: liufengyun

compiler/src/dotty/tools/dotc/transform/patmat/Space.scala

@@ -424,7 +424,7 @@ class SpaceEngine(implicit ctx: Context) extends SpaceLogic {
         List()
       else {
         val isUnapplySeq = unappSym.name == nme.unapplySeq
-        if (isProductMatch(mt.finalResultType, argLen) && !isUnapplySeq) {
+        if (productArity(mt.finalResultType, unappSym.sourcePos) > 0 && !isUnapplySeq) {
           productSelectors(mt.finalResultType).take(argLen)
             .map(_.info.asSeenFrom(mt.finalResultType, mt.resultType.classSymbol).widenExpr)
         }

tests/neg/i3248.scala

@@ -0,0 +1,27 @@
+object Test {
+  class Foo(val name: String, val children: Int *)
+  object Foo {
+    def unapply(f: Foo) = Some((f.name, f.children))
+  }
+
+  def foo(f: Foo) = f match {
+    case Foo(name, ns: _*) =>
+      assert(name == "hello")
+      assert(ns(0) == 3)
+      assert(ns(1) == 5)
+  }
+
+  def bar(f: Foo) = f match {
+    case Foo(name, x, y, ns : _*) =>
+      assert(name == "hello")
+      assert(x == 3)
+      assert(y == 5)
+      assert(ns.isEmpty)
+  }
+
+  def main(args: Array[String]): Unit = {
+    val f = new Foo("hello", 3, 5)
+    foo(f)
+    bar(f)
+  }
+}

tests/run/i3248b.scala

@@ -0,0 +1,24 @@
+object Test {
+  case class Foo(name: String, children: Int *)
+
+  def foo(f: Foo) = f match {
+    case Foo(name, ns: _*) =>
+      assert(name == "hello")
+      assert(ns(0) == 3)
+      assert(ns(1) == 5)
+  }
+
+  def bar(f: Foo) = f match {
+    case Foo(name, x, y, ns : _*) =>
+      assert(name == "hello")
+      assert(x == 3)
+      assert(y == 5)
+      assert(ns.isEmpty)
+  }
+
+  def main(args: Array[String]): Unit = {
+    val f = new Foo("hello", 3, 5)
+    foo(f)
+    bar(f)
+  }
+}