Fixes #3935.

No review.

3 files changed, 21 insertions, 4 deletions

diff --git a/src/library/scala/collection/immutable/ListMap.scala b/src/library/scala/collection/immutable/ListMap.scala
index 28d2f637db..53c99216c2 100644
--- a/src/library/scala/collection/immutable/ListMap.scala
+++ b/src/library/scala/collection/immutable/ListMap.scala
@@ -192,7 +192,7 @@ class ListMap[A, +B] extends Map[A, B] with MapLike[A, B, ListMap[A, B]] {
       //   if (tail eq next) this
       //   else new tail.Node(key, value)
       // }
-      // we use an imperative one instead:
+      // we use an imperative one instead (and use an auxiliary list to preserve order!):
       var cur: ListMap[A, B1] = this
       var lst: List[(A, B1)] = Nil
       while (cur.nonEmpty) {
diff --git a/src/library/scala/collection/mutable/MutableList.scala b/src/library/scala/collection/mutable/MutableList.scala
index 65c973c9ec..a81cb27cf1 100644
--- a/src/library/scala/collection/mutable/MutableList.scala
+++ b/src/library/scala/collection/mutable/MutableList.scala
@@ -42,7 +42,7 @@ class MutableList[A] extends LinearSeq[A]
 
   /** Returns the first element in this list
    */
-  override def head: A = first0.head
+  override def head: A = if (nonEmpty) first0.head else throw new NoSuchElementException
 
   /** Returns the rest of this list
    */
@@ -134,3 +134,12 @@ class MutableList[A] extends LinearSeq[A]
 
   def result = this
 }
+
+
+object MutableList {
+
+}
+
+
+
+
diff --git a/src/library/scala/collection/mutable/Queue.scala b/src/library/scala/collection/mutable/Queue.scala
index ae6c60d1d0..9fb34b07aa 100644
--- a/src/library/scala/collection/mutable/Queue.scala
+++ b/src/library/scala/collection/mutable/Queue.scala
@@ -30,6 +30,14 @@ import generic._
  */
 @serializable @cloneable
 class Queue[A] extends MutableList[A] with Cloneable[Queue[A]] {
+
+  protected def this(fst: LinkedList[A], lst: LinkedList[A], lng: Int) {
+    this()
+    first0 = fst
+    last0 = lst
+    len = lng
+  }
+
   /** Adds all elements to the queue.
    *
    *  @param  elems       the elements to add.
@@ -147,10 +155,10 @@ class Queue[A] extends MutableList[A] with Cloneable[Queue[A]] {
    *
    *  @return the first element.
    */
-  def front: A = first0.elem
+  def front: A = head
 }
 
-// !!! TODO - integrate
+
 object Queue {
   def apply[A](xs: A*): Queue[A] = new Queue[A] ++= xs
 }