List.separate results in StackOverflowError

[scabug]

scala> List.separate(List.range(1,100000).map(Left(_)))
java.lang.StackOverflowError
        at scala.List.foldRight(List.scala:1067)
        at scala.List.foldRight(List.scala:1067)
        at scala.List.foldRight(List.scala:1067)
        at scala.List.foldRight(List.scala:1067)
        at scala.List.foldRight(List.scala:1067)
        at scala.List.foldRight(List.scala:1067)
        at scala.List.foldRight(List.scala:1067)
        at scala.List.foldRight(List.scala:1067)
        at scala.List.foldRig...

Why is List.separate using foldRight? (Or maybe the question is: why is foldRight implemented using recursion that can lead to stack overflows?) It should probably use the same logic as Iterable.partition. Here's an implementation that would work:

def separate[A,B](l: List[Either[A,B]]) = {
  val (lefts, rights) = l.partition(_.isLeft)
  (lefts.map(_.left.get), rights.map(_.right.get))
}

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-1437?orig=1
Reporter: @pchiusano
Assignee: @tonymorris

[scabug]

@odersky said:
Tony, one other thing: In 2.8.0 lefts/rights/separate should be moved from
object List to object Either. More precisely, we are deprecating them in List, and will remove them afterwards. If you do the fix, can you already add the fixed versions to Either? Thanks! -- Martin

[scabug]

@tonymorris said:
No problem, what time frame do we have?

[scabug]

@paulp said:
Ticket survived long enough for the method in question to transition through the whole deprecation period and reach its EOL.