SI-6632 ListBuffer's updated accepts negative positions

Changed the behavior in SeqLike.updated (which would silently accept negatives and throw on empty.tail) to throw IndexOutOfBoundException.

Updated tests to verify the behavior in ListBuffer.  Everything else SeqLike will come along for the ride.

3 files changed, 17 insertions, 19 deletions

diff --git a/src/library/scala/collection/SeqLike.scala b/src/library/scala/collection/SeqLike.scala
index 960c277f67..fdfb1f2efc 100644
--- a/src/library/scala/collection/SeqLike.scala
+++ b/src/library/scala/collection/SeqLike.scala
@@ -509,11 +509,14 @@ trait SeqLike[+A, +Repr] extends Any with IterableLike[A, Repr] with GenSeqLike[
   }
 
   def updated[B >: A, That](index: Int, elem: B)(implicit bf: CanBuildFrom[Repr, B, That]): That = {
+    if (index < 0) throw new IndexOutOfBoundsException(index.toString)
     val b = bf(repr)
     val (prefix, rest) = this.splitAt(index)
+    val restColl = toCollection(rest)
+    if (restColl.isEmpty) throw new IndexOutOfBoundsException(index.toString)
     b ++= toCollection(prefix)
     b += elem
-    b ++= toCollection(rest).view.tail
+    b ++= restColl.view.tail
     b.result()
   }
 
diff --git a/test/files/run/t6632.check b/test/files/run/t6632.check
index 1f084b1dac..26cf061b5f 100644
--- a/test/files/run/t6632.check
+++ b/test/files/run/t6632.check
@@ -1,3 +1,5 @@
 java.lang.IndexOutOfBoundsException: -1
 java.lang.IndexOutOfBoundsException: -2
 java.lang.IndexOutOfBoundsException: -3
+java.lang.IndexOutOfBoundsException: -1
+java.lang.IndexOutOfBoundsException: 5
diff --git a/test/files/run/t6632.scala b/test/files/run/t6632.scala
index 0242e60104..f338b73fa6 100644
--- a/test/files/run/t6632.scala
+++ b/test/files/run/t6632.scala
@@ -3,27 +3,20 @@ object Test extends App {
 
   def newLB = ListBuffer('a, 'b, 'c, 'd, 'e)
 
-  val lb0 = newLB
+  def iiobe[A](f: => A) =
+    try { f }
+    catch { case ex: IndexOutOfBoundsException => println(ex) }
 
-  try {
-    lb0.insert(-1, 'x)
-  } catch {
-    case ex: IndexOutOfBoundsException => println(ex)
-  }
+  val lb0 = newLB
+  iiobe( lb0.insert(-1, 'x) )
 
   val lb1 = newLB
-
-  try {
-    lb1.insertAll(-2, Array('x, 'y, 'z))
-  } catch {
-    case ex: IndexOutOfBoundsException => println(ex)
-  }
+  iiobe( lb1.insertAll(-2, Array('x, 'y, 'z)) )
 
   val lb2 = newLB
+  iiobe( lb2.update(-3, 'u) )
 
-  try {
-    lb2.update(-3, 'u)
-  } catch {
-    case ex: IndexOutOfBoundsException => println(ex)
-  }
-}
\ No newline at end of file
+  val lb3 = newLB
+  iiobe( lb3.updated(-1, 'u) )
+  iiobe( lb3.updated(5, 'u) )
+}