Fixes SI-8014, regression in Vector ++ TraversableOnce.

Now uses the cached copy instead of the exhausted iterator.  Adds a JUnit
test for ++.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/library/scala/collection/immutable/Vector.scala b/src/library/scala/collection/immutable/Vector.scala
index 0a100578c0..3dc1ad6a79 100644
--- a/src/library/scala/collection/immutable/Vector.scala
+++ b/src/library/scala/collection/immutable/Vector.scala
@@ -227,7 +227,7 @@ override def companion: GenericCompanion[Vector] = Vector
             val ri = this.reverseIterator
             while (ri.hasNext) v = ri.next +: v
             v.asInstanceOf[That]
-          case _ => super.++(that)
+          case _ => super.++(again)
         }
       }
     }