diff options
-rw-r--r-- | src/reflect/scala/reflect/internal/Trees.scala | 13 | ||||
-rw-r--r-- | test/files/pos/t6648.scala | 24 |
2 files changed, 37 insertions, 0 deletions
diff --git a/src/reflect/scala/reflect/internal/Trees.scala b/src/reflect/scala/reflect/internal/Trees.scala index 53b40da8f6..b8f5e73acb 100644 --- a/src/reflect/scala/reflect/internal/Trees.scala +++ b/src/reflect/scala/reflect/internal/Trees.scala @@ -482,6 +482,10 @@ trait Trees extends api.Trees { self: SymbolTable => case class TypeTree() extends TypTree with TypeTreeContextApi { private var orig: Tree = null + /** Was this type tree originally empty? That is, does it now contain + * an inferred type that must be forgotten in `resetAttrs` to + * enable retyping. + */ private[scala] var wasEmpty: Boolean = false override def symbol = typeTreeSymbol(this) // if (tpe == null) null else tpe.typeSymbol @@ -502,6 +506,15 @@ trait Trees extends api.Trees { self: SymbolTable => wasEmpty = isEmpty setType(tp) } + + override private[scala] def copyAttrs(tree: Tree) = { + super.copyAttrs(tree) + tree match { + case other: TypeTree => wasEmpty = other.wasEmpty // SI-6648 Critical for correct operation of `resetAttrs`. + case _ => + } + this + } } object TypeTree extends TypeTreeExtractor diff --git a/test/files/pos/t6648.scala b/test/files/pos/t6648.scala new file mode 100644 index 0000000000..9593ebfee9 --- /dev/null +++ b/test/files/pos/t6648.scala @@ -0,0 +1,24 @@ +abstract class Node extends NodeSeq +trait NodeSeq extends Seq[Node] +object NodeSeq { + implicit def seqToNodeSeq(ns: Seq[Node]): NodeSeq = ??? + def foo[B, That](f: Seq[B])(implicit bf: scala.collection.generic.CanBuildFrom[Seq[Int], B, That]): That = ??? +} + +class Transformer { + def apply(nodes: Any): Any = ??? +} + +object transformer1 extends Transformer { + // Adding explicit type arguments, or making the impilcit view + // seqToNodeSeq explicit avoids the crash + NodeSeq.foo { + // These both avoid the crash: + // val t = new Transformer {}; t.apply(null) + // new Transformer().apply(null) + new Transformer {}.apply(null) + + null: NodeSeq + }: NodeSeq +} + |