Merge pull request scala#3530 from Ichoran/issue/6632

SI-6632 ListBuffer's updated accepts negative positions

Author: adriaanm

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()
   }
 

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

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)
-  }
-}
+  val lb3 = newLB
+  iiobe( lb3.updated(-1, 'u) )
+  iiobe( lb3.updated(5, 'u) )
+}