Fix SI-5009: case-class copy method now eta-expands over higher parameter lists.

Example: Given

  case class C(a: Int)(b: Int)

if you call (new C(1)(2)).copy(a = 10)), you get a function (f: Int => C) such
that (f.apply(20)) yields a (new C(10)(20)).

1 files changed, 17 insertions, 0 deletions

diff --git a/test/files/run/t5009.scala b/test/files/run/t5009.scala
new file mode 100644
index 0000000000..b4fe1bc894
--- /dev/null
+++ b/test/files/run/t5009.scala
@@ -0,0 +1,17 @@
+object Test extends App {
+
+  case class C[T, U <: String, O >: Object](x: Int, y: T)(z: U, b: Boolean)(s: O, val l: Int)
+
+  val c = C(1, true)("dlkfj", true)("dlkfjlk", 10)
+  println(c)
+  println(c.l)
+
+  val f1a = c.copy(y = 20, x = 7283)
+
+  val f1b = c.copy[Int, String, Object](y = 20, x = 7283)
+  val f2b = f1b("lkdjen", false)
+  val res = f2b(new Object, 100)
+  println(res)
+  println(res.l)
+  
+}