Merge pull request #5322 from dotty-staging/fix-#5271

Fix #5271: Use typed elements

Author: nicolasstucki

compiler/src/dotty/tools/dotc/typer/Typer.scala

@@ -1794,22 +1794,21 @@ class Typer extends Namer
 
   /** Translate tuples of all arities */
   def typedTuple(tree: untpd.Tuple, pt: Type)(implicit ctx: Context): Tree = {
-    val elems = tree.trees
-    val arity = elems.length
+    val arity = tree.trees.length
     if (arity <= Definitions.MaxTupleArity)
       typed(desugar.smallTuple(tree).withPos(tree.pos), pt)
     else {
       val pts =
         if (arity == pt.tupleArity) pt.tupleElementTypes
-        else elems.map(_ => defn.AnyType)
-      val elems1 = (tree.trees, pts).zipped.map(typed(_, _))
+        else List.fill(arity)(defn.AnyType)
+      val elems = (tree.trees, pts).zipped.map(typed(_, _))
       if (ctx.mode.is(Mode.Type))
-        (elems1 :\ (TypeTree(defn.UnitType): Tree))((elemTpt, elemTpts) =>
+        (elems :\ (TypeTree(defn.UnitType): Tree))((elemTpt, elemTpts) =>
           AppliedTypeTree(TypeTree(defn.PairType), List(elemTpt, elemTpts)))
           .withPos(tree.pos)
       else {
         val tupleXXLobj = untpd.ref(defn.TupleXXLModule.termRef)
-        val app = untpd.cpy.Apply(tree)(tupleXXLobj, elems1.map(untpd.TypedSplice(_)))
+        val app = untpd.cpy.Apply(tree)(tupleXXLobj, elems.map(untpd.TypedSplice(_)))
           .withPos(tree.pos)
         val app1 = typed(app, defn.TupleXXLType)
         if (ctx.mode.is(Mode.Pattern)) app1

tests/pos/i5271.scala

@@ -0,0 +1,6 @@
+class Foo {
+  def foo: Unit = {
+    val (_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) =
+      (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, List(2, 1), 22, 23)
+  }
+}