Fix #5269: Fix StagedTuple/Tuple implementation

Author: nicolasstucki

compiler/test/dotty/tools/dotc/CompilationTests.scala

@@ -171,6 +171,7 @@ class CompilationTests extends ParallelTesting {
   @Test def runAll: Unit = {
     implicit val testGroup: TestGroup = TestGroup("runAll")
     compileFilesInDir("tests/run-custom-args/Yretain-trees", defaultOptions and "-Yretain-trees") +
+    compileFile("tests/run-custom-args/tuple-cons.scala", allowDeepSubtypes) +
     compileFilesInDir("tests/run", defaultOptions)
   }.checkRuns()
 

library/src-scala3/scala/StagedTuple.scala

@@ -190,7 +190,7 @@ object StagedTuple {
       case Some(4) =>
         self.as[Tuple4[_, _, _, _]].bind(t => '(Tuple5(~x, (~t)._1, (~t)._2, (~t)._3, (~t)._4)))
       case Some(n) =>
-        fromArrayStaged('($consArray(~x, ~toArrayStaged(self, tailSize))), Some(n + 1))
+        fromArrayStaged[H *: T]('($consArray(~x, ~toArrayStaged(self, tailSize))), Some(n + 1))
       case _ =>
         '(dynamic_*:[T, H](~self, ~x))
     }

library/src-scala3/scala/Tuple.scala

@@ -131,7 +131,7 @@ object Tuple {
       val t = self.asInstanceOf[Tuple4[Object, Object, Object, Object]]
       Array(t._1, t._2, t._3, t._4)
     case self: TupleXXL =>
-      asInstanceOf[TupleXXL].elems
+      self.elems
     case self: Product =>
       val arr = new Array[Object](self.productArity)
       for (i <- 0 until arr.length) arr(i) = self.productElement(i).asInstanceOf[Object]

tests/pending/tuple-cons.scala renamed to tests/run-custom-args/tuple-cons.scala

@@ -0,0 +1,7 @@
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val t6: (Int,Int,Int,Int,Int,Int) = 1 *: (2, 3, 4, 5, 6)
+    println(t6)
+  }
+}