--- a/dwt/widgets/TreeItem.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/TreeItem.d	Sun Jun 15 22:32:20 2008 +0200
@@ -27,7 +27,6 @@
 import dwt.widgets.Tree;
 import dwt.widgets.ImageList;
 
-static import tango.stdc.stringz;
 import Math = tango.math.Math;
 
 /**
@@ -289,7 +288,7 @@
     int modelIndex = parent.columnCount is 0 ? Tree.FIRST_COLUMN : parent.columns [index].modelIndex;
     OS.gtk_tree_model_get1 (parent.modelHandle, handle, modelIndex + Tree.CELL_TEXT, &ptr);
     if (ptr is null) return ""; //$NON-NLS-1$
-    char[] buffer = tango.stdc.stringz.fromStringz( cast(char*)ptr).dup;
+    char[] buffer = fromStringz( cast(char*)ptr).dup;
     OS.g_free (ptr);
     return buffer;
 }
@@ -1657,7 +1656,6 @@
  * @param images the array of new images
  *
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the array of images is null</li>
  *    <li>ERROR_INVALID_ARGUMENT - if one of the images has been disposed</li>
  * </ul>
  * @exception DWTException <ul>
@@ -1669,7 +1667,8 @@
  */
 public void setImage (Image [] images) {
     checkWidget ();
-    if (images is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (images is null) error (DWT.ERROR_NULL_ARGUMENT);
     for (int i=0; i<images.length; i++) {
         setImage (i, images [i]);
     }
@@ -1699,9 +1698,6 @@
  * @param index the column index
  * @param string the new text
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the text is null</li>
- * </ul>
  * @exception DWTException <ul>
  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
@@ -1711,11 +1707,12 @@
  */
 public void setText (int index, String string) {
     checkWidget ();
-    if (string is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (string is null) error (DWT.ERROR_NULL_ARGUMENT);
     if (_getText (index).equals (string)) return;
     int count = Math.max (1, parent.getColumnCount ());
     if (0 > index || index > count - 1) return;
-    char* buffer = tango.stdc.stringz.toStringz(string);
+    char* buffer = toStringz(string);
     int modelIndex = parent.columnCount is 0 ? Tree.FIRST_COLUMN : parent.columns [index].modelIndex;
     OS.gtk_tree_store_set1 (parent.modelHandle, cast(GtkTreeIter*)handle, modelIndex + Tree.CELL_TEXT, buffer);
     /*
@@ -1741,9 +1738,6 @@
  *
  * @param strings the array of new strings
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the text is null</li>
- * </ul>
  * @exception DWTException <ul>
  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
@@ -1753,7 +1747,8 @@
  */
 public void setText (String [] strings) {
     checkWidget ();
-    if (strings is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (strings is null) error (DWT.ERROR_NULL_ARGUMENT);
     for (int i=0; i<strings.length; i++) {
         String string = strings [i];
         if (string !is null) setText (i, string);