Fix SI-4813 - Clone doesn't work on LinkedList.

* Added extensive test for clone across all standard mutable collections
* Fixed clone implementations when needed so they work.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/library/scala/collection/mutable/LinkedListLike.scala b/src/library/scala/collection/mutable/LinkedListLike.scala
index 07a8501ca4..59004a3de6 100644
--- a/src/library/scala/collection/mutable/LinkedListLike.scala
+++ b/src/library/scala/collection/mutable/LinkedListLike.scala
@@ -180,4 +180,14 @@ trait LinkedListLike[A, This <: Seq[A] with LinkedListLike[A, This]] extends Seq
       these = these.next
     }
   }
+
+  /** Return a clone of this list.
+   *
+   *  @return a `LinkedList` with the same elements.
+   */
+  override def clone(): This = {
+    val bf = newBuilder
+    bf ++= this
+    bf.result
+  }
 }