Dialog.java (constructor): Accept null title as per spec.

* java/awt/Dialog.java (constructor): Accept null title as per spec.
        * java/awt/FileDialog.java (constructor): Throw exception on invalid
        argument as per spec.

From-SVN: r75444

libjava/java/awt/Dialog.java

@@ -187,7 +187,8 @@ Dialog (Frame parent, String title, boolean modal, GraphicsConfiguration gc)
 {
   super (parent, gc);
 
-  this.title = title;
+  // A null title is equivalent to an empty title  
+  this.title = (title != null) ? title : "";
   this.modal = modal;
   visible = false;
 
@@ -254,8 +255,9 @@ public
 Dialog (Dialog parent, String title, boolean modal, GraphicsConfiguration gc)
 {
   super (parent, parent.getGraphicsConfiguration ());
-  
-  this.title = title;
+
+  // A null title is equivalent to an empty title  
+  this.title = (title != null) ? title : "";
   this.modal = modal;
   visible = false;
 
@@ -289,7 +291,9 @@ getTitle()
 public synchronized void
 setTitle(String title)
 {
-  this.title = title;
+  // A null title is equivalent to an empty title  
+  this.title = (title != null) ? title : "";
+
   if (peer != null)
     {
       DialogPeer d = (DialogPeer) peer;

libjava/java/awt/FileDialog.java

@@ -147,6 +147,11 @@ public
 FileDialog(Frame parent, String title, int mode)
 {
   super(parent, title, true);
+  
+  if ((mode != LOAD) && (mode != SAVE))
+    throw new IllegalArgumentException (
+      "Mode argument must be either LOAD or SAVE");
+
   setMode (mode);
 }