Use Vector for non-immutable collecitons

Author: lrytz

shared/src/main/scala/scala/xml/NodeSeq.scala

@@ -26,7 +26,10 @@ import scala.collection.Seq
 object NodeSeq {
   final val Empty: NodeSeq = fromSeq(Nil)
   def fromSeq(s: Seq[Node]): NodeSeq = new NodeSeq {
-    override def theSeq: ScalaVersionSpecific.SeqOfNode = s.toSeq
+    override def theSeq: ScalaVersionSpecific.SeqOfNode = s match {
+      case ns: ScalaVersionSpecific.SeqOfNode => ns
+      case _ => s.toVector
+    }
   }
 
   // ---

shared/src/main/scala/scala/xml/PrefixedAttribute.scala

@@ -32,7 +32,10 @@ class PrefixedAttribute(
 )
   extends Attribute
 {
-  override val value: ScalaVersionSpecific.SeqOfNode = if (_value == null) null else _value.toSeq
+  override val value: ScalaVersionSpecific.SeqOfNode = if (_value == null) null else _value match {
+    case ns: ScalaVersionSpecific.SeqOfNode => ns
+    case _ => _value.toVector
+  }
 
   override val next: MetaData = if (value != null) next1 else next1.remove(key)
 

shared/src/main/scala/scala/xml/UnprefixedAttribute.scala

@@ -28,7 +28,10 @@ class UnprefixedAttribute(
 )
   extends Attribute
 {
-  override val value: ScalaVersionSpecific.SeqOfNode = if (_value == null) null else _value.toSeq
+  override val value: ScalaVersionSpecific.SeqOfNode = if (_value == null) null else _value match {
+    case ns: ScalaVersionSpecific.SeqOfNode => ns
+    case _ => _value.toVector
+  }
 
   final override val pre: scala.Null = null
   override val next: MetaData = if (value != null) next1 else next1.remove(key)