Fixes SI-4461.

No review.

Author: Aleksandar Prokopec

src/library/scala/collection/mutable/ObservableBuffer.scala

@@ -70,4 +70,18 @@ trait ObservableBuffer[A] extends Buffer[A] with Publisher[Message[A] with Undoa
       def undo() { throw new UnsupportedOperationException("cannot undo") }
     })
   }
+  
+  abstract override def insertAll(n: Int, elems: collection.Traversable[A]) {
+    super.insertAll(n, elems)
+    var curr = n - 1
+    val msg = elems.foldLeft(new Script[A]() with Undoable {
+      def undo() { throw new UnsupportedOperationException("cannot undo") }
+    }) {
+      case (msg, elem) =>
+        curr += 1
+        msg += Include(Index(curr), elem)
+    }
+    publish(msg)
+  }
+  
 }

test/files/run/t4461.check

@@ -4,4 +4,8 @@ Include(End,3)
 Include(End,4)
 Include(End,5)
 Include(End,6)
-Include(End,7)
+Include(End,7)
+Script([1] Include(Index(7),8), [2] Include(Index(8),9), [3] Include(Index(9),10))
+Include(Start,0)
+Script([1] Include(Index(0),-2), [2] Include(Index(1),-1))
+Remove(Index(0),-2)

test/files/run/t4461.scala

@@ -15,5 +15,9 @@ object Test {
     buf ++= ArrayBuffer(3, 4) // works
     buf ++= List(5) // works
     buf ++= collection.immutable.Vector(6, 7) // works
+    buf.insertAll(7, List(8, 9, 10))
+    0 +=: buf
+    List(-2, -1) ++=: buf
+    buf remove 0
   }
 }