Fixes NPE using iterator with an XML attribute ...

Fixes NPE using iterator with an XML attribute being null or None      )
(SI-5052 Also fixes incorrect size method (SI-5115                     )

Contributed by Jordi Salvat i Alabart. Closes SI-5052, SI-5115, no
review.

3 files changed, 12 insertions, 4 deletions

diff --git a/src/library/scala/xml/Attribute.scala b/src/library/scala/xml/Attribute.scala
index 9523891a9c..6b68e97412 100644
--- a/src/library/scala/xml/Attribute.scala
+++ b/src/library/scala/xml/Attribute.scala
@@ -73,6 +73,17 @@ abstract trait Attribute extends MetaData {
     (next(arg, scope, key) == null) && (next wellformed scope)
   }
 
+  /** Returns an iterator on attributes */
+  override def iterator: Iterator[MetaData] = {
+    if (value == null) next.iterator
+    else Iterator.single(this) ++ next.iterator
+  }
+
+  override def size: Int = {
+    if (value == null) next.size
+    else 1 + next.size
+  }
+
   /** Appends string representation of only this attribute to stringbuffer.
    */
   protected def toString1(sb: StringBuilder) {
diff --git a/src/library/scala/xml/MetaData.scala b/src/library/scala/xml/MetaData.scala
index 9c603141d5..62d235ee12 100644
--- a/src/library/scala/xml/MetaData.scala
+++ b/src/library/scala/xml/MetaData.scala
@@ -141,10 +141,6 @@ abstract class MetaData extends Iterable[MetaData] with Equality with Serializab
   }
   protected def basisForHashCode: Seq[Any] = List(this.asAttrMap)
 
-  /** Returns an iterator on attributes */
-  def iterator: Iterator[MetaData] = Iterator.single(this) ++ next.iterator
-  override def size: Int = 1 + iterator.length
-
   /** filters this sequence of meta data */
   override def filter(f: MetaData => Boolean): MetaData =
     if (f(this)) copy(next filter f)
diff --git a/src/library/scala/xml/Null.scala b/src/library/scala/xml/Null.scala
index 0db4a074c5..2c1c569a44 100644
--- a/src/library/scala/xml/Null.scala
+++ b/src/library/scala/xml/Null.scala
@@ -20,6 +20,7 @@ import scala.collection.Iterator
  */
 case object Null extends MetaData {
   override def iterator = Iterator.empty
+  override def size = 0
   override def append(m: MetaData, scope: NamespaceBinding = TopScope): MetaData = m
   override def filter(f: MetaData => Boolean): MetaData = this