3 files changed, 4 insertions, 5 deletions
diff --git a/src/library/scala/collection/immutable/List.scala b/src/library/scala/collection/immutable/List.scala
index aa9dec2761..9bfefc3de2 100644
--- a/src/library/scala/collection/immutable/List.scala
+++ b/src/library/scala/collection/immutable/List.scala
@@ -290,7 +290,6 @@ sealed abstract class List[+A] extends AbstractSeq[A]
       if (this eq Nil) Nil.asInstanceOf[That] else {
         var rest = this
         var h: ::[B] = null
-        var x: A = null.asInstanceOf[A]
         // Special case for first element
         do {
           val x: Any = pf.applyOrElse(rest.head, List.partialNotApplied)
diff --git a/src/library/scala/collection/mutable/AnyRefMap.scala b/src/library/scala/collection/mutable/AnyRefMap.scala
index 47fb66744e..fccc9d83e6 100644
--- a/src/library/scala/collection/mutable/AnyRefMap.scala
+++ b/src/library/scala/collection/mutable/AnyRefMap.scala
@@ -224,7 +224,7 @@ extends AbstractMap[K, V]
   override def put(key: K, value: V): Option[V] = {
     val h = hashOf(key)
     val k = key
-    var i = seekEntryOrOpen(h, k)
+    val i = seekEntryOrOpen(h, k)
     if (i < 0) {
       val j = i & IndexMask
       _hashes(j) = h
@@ -251,7 +251,7 @@ extends AbstractMap[K, V]
   override def update(key: K, value: V): Unit = {
     val h = hashOf(key)
     val k = key
-    var i = seekEntryOrOpen(h, k)
+    val i = seekEntryOrOpen(h, k)
     if (i < 0) {
       val j = i & IndexMask
       _hashes(j) = h
diff --git a/src/library/scala/collection/mutable/LongMap.scala b/src/library/scala/collection/mutable/LongMap.scala
index ef488a3697..5fafe23d9f 100644
--- a/src/library/scala/collection/mutable/LongMap.scala
+++ b/src/library/scala/collection/mutable/LongMap.scala
@@ -81,7 +81,7 @@ extends AbstractMap[Long, V]
   private def toIndex(k: Long): Int = {
     // Part of the MurmurHash3 32 bit finalizer
     val h = ((k ^ (k >>> 32)) & 0xFFFFFFFFL).toInt
-    var x = (h ^ (h >>> 16)) * 0x85EBCA6B
+    val x = (h ^ (h >>> 16)) * 0x85EBCA6B
     (x ^ (x >>> 13)) & mask
   }
   
@@ -311,7 +311,7 @@ extends AbstractMap[Long, V]
       }
     }
     else {
-      var i = seekEntryOrOpen(key)
+      val i = seekEntryOrOpen(key)
       if (i < 0) {
         val j = i & IndexMask
         _keys(j) = key