Fix for slice boundary condition.

Negative "to" index should be normalized to 0 before using it
in a difference operation.

Author: paulp

src/library/scala/collection/IndexedSeqOptimized.scala

@@ -104,7 +104,7 @@ trait IndexedSeqOptimized[+A, +Repr] extends IndexedSeqLike[A, Repr] { self =>
   override /*IterableLike*/
   def slice(from: Int, until: Int): Repr = {
     val lo    = math.max(from, 0)
-    val hi    = math.min(until, length)
+    val hi    = math.min(math.max(until, 0), length)
     val elems = math.max(hi - lo, 0)
     val b     = newBuilder
     b.sizeHint(elems)

test/files/run/buffer-slice.check

@@ -0,0 +1 @@
+ArrayBuffer()

test/files/run/buffer-slice.scala

@@ -0,0 +1,5 @@
+object Test {
+  def main(args: Array[String]): Unit = {
+    println(scala.collection.mutable.ArrayBuffer().slice(102450392, -2045033354))
+  }
+}