# HG changeset patch
# User Frank Benoit <benoit@tionex.de>
# Date 1213561940 -7200
# Node ID 5a30aa9820f3a17d029b1c70bef455358c87c288
# Parent  8bca790583c33525f6196ef2a0eeb4879bc32370
removed tango.stdc.stringz imports and allow null for arrays and string arguments.

diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/accessibility/AccessibleFactory.d
--- a/dwt/accessibility/AccessibleFactory.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/accessibility/AccessibleFactory.d	Sun Jun 15 22:32:20 2008 +0200
@@ -25,7 +25,6 @@
 
 import dwt.DWT;
 
-import tango.stdc.stringz;
 import tango.io.Stdout;
 
 class AccessibleFactory {
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/accessibility/AccessibleObject.d
--- a/dwt/accessibility/AccessibleObject.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/accessibility/AccessibleObject.d	Sun Jun 15 22:32:20 2008 +0200
@@ -26,7 +26,6 @@
 import dwt.widgets.Display;
 import dwt.dwthelper.utils;
 import tango.io.Stdout;
-import tango.stdc.stringz;
 import tango.text.Util;
 import Math = tango.math.Math;
 
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/custom/CCombo.d
--- a/dwt/custom/CCombo.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/custom/CCombo.d	Sun Jun 15 22:32:20 2008 +0200
@@ -192,9 +192,6 @@
  *
  * @param string the new item
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string 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>
@@ -204,7 +201,8 @@
  */
 public void add (String string) {
     checkWidget();
-    if (string is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (string is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
     list.add (string);
 }
 /**
@@ -220,7 +218,6 @@
  * @param index the index for the item
  *
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
  *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list (inclusive)</li>
  * </ul>
  * @exception DWTException <ul>
@@ -232,7 +229,8 @@
  */
 public void add (String string, int index) {
     checkWidget();
-    if (string is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (string is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
     list.add (string, index);
 }
 /**
@@ -869,9 +867,6 @@
  * @param string the search item
  * @return the index of the item
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string 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>
@@ -879,7 +874,8 @@
  */
 public int indexOf (String string) {
     checkWidget ();
-    if (string is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (string is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
     return list.indexOf (string);
 }
 /**
@@ -893,9 +889,6 @@
  * @param start the zero-relative index at which to begin the search
  * @return the index of the item
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string 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>
@@ -903,7 +896,8 @@
  */
 public int indexOf (String string, int start) {
     checkWidget ();
-    if (string is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (string is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
     return list.indexOf (string, start);
 }
 
@@ -1237,7 +1231,6 @@
  * @param string the item to remove
  *
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
  *    <li>ERROR_INVALID_ARGUMENT - if the string is not found in the list</li>
  * </ul>
  * @exception DWTException <ul>
@@ -1247,7 +1240,8 @@
  */
 public void remove (String string) {
     checkWidget();
-    if (string is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (string is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
     list.remove (string);
 }
 /**
@@ -1421,7 +1415,6 @@
  *
  * @exception IllegalArgumentException <ul>
  *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)</li>
- *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
  * </ul>
  * @exception DWTException <ul>
  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
@@ -1438,7 +1431,6 @@
  * @param items the array of items
  *
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the items array is null</li>
  *    <li>ERROR_INVALID_ARGUMENT - if an item in the items array is null</li>
  * </ul>
  * @exception DWTException <ul>
@@ -1530,9 +1522,6 @@
  *
  * @param string the new text
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string 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>
@@ -1540,7 +1529,8 @@
  */
 public void setText (String string) {
     checkWidget();
-    if (string is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (string is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
     int index = list.indexOf (string);
     if (index is -1) {
         list.deselectAll ();
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/custom/CTabItem.d
--- a/dwt/custom/CTabItem.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/custom/CTabItem.d	Sun Jun 15 22:32:20 2008 +0200
@@ -772,14 +772,14 @@
  * Returns <code>true</code> to indicate that the receiver's close button should be shown.
  * Otherwise return <code>false</code>. The initial value is defined by the style (DWT.CLOSE)
  * that was used to create the receiver.
- * 
+ *
  * @return <code>true</code> if the close button should be shown
  *
  * @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>
  * </ul>
- * 
+ *
  * @since 3.4
  */
 public bool getShowClose() {
@@ -1021,14 +1021,14 @@
  * Sets to <code>true</code> to indicate that the receiver's close button should be shown.
  * If the parent (CTabFolder) was created with DWT.CLOSE style, changing this value has
  * no effect.
- * 
+ *
  * @param close the new state of the close button
  *
  * @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>
  * </ul>
- * 
+ *
  * @since 3.4
  */
 public void setShowClose(bool close) {
@@ -1040,8 +1040,9 @@
 }
 public override void setText (String string) {
     checkWidget();
-    if (string is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
-    if (string==getText()) return;
+    // DWT extension: allow null for zero length string
+    //if (string is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
+    if (string.equals (getText())) return;
     super.setText(string);
     shortenedText = null;
     shortenedTextWidth = 0;
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/custom/PopupList.d
--- a/dwt/custom/PopupList.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/custom/PopupList.d	Sun Jun 15 22:32:20 2008 +0200
@@ -1,4 +1,4 @@
-/*******************************************************************************
+/*******************************************************************************
  * Copyright (c) 2000, 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
@@ -263,7 +263,6 @@
 * or could not be added in the OS.
 *
 * @exception IllegalArgumentException <ul>
-*    <li>ERROR_NULL_ARGUMENT - if the items array is null</li>
 *    <li>ERROR_INVALID_ARGUMENT - if an item in the items array is null</li>
 * </ul>
 * @exception DWTException <ul>
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/custom/StyledText.d
--- a/dwt/custom/StyledText.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/custom/StyledText.d	Sun Jun 15 22:32:20 2008 +0200
@@ -1598,15 +1598,13 @@
  *    <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>
  * </ul>
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT when listener is null</li>
- * </ul>
  */
 public void append(String string) {
     checkWidget();
-    if (string is null) {
-        DWT.error(DWT.ERROR_NULL_ARGUMENT);
-    }
+    // DWT extension: allow null for zero length string
+//     if (string is null) {
+//         DWT.error(DWT.ERROR_NULL_ARGUMENT);
+//     }
     int lastChar = Math.max(getCharCount(), 0);
     replaceTextRange(lastChar, 0, string);
 }
@@ -4934,15 +4932,13 @@
  *    <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>
  * </ul>
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT when string is null</li>
- * </ul>
  */
 public void insert(String string) {
     checkWidget();
-    if (string is null) {
-        DWT.error(DWT.ERROR_NULL_ARGUMENT);
-    }
+    // DWT extension: allow null for zero length string
+//     if (string is null) {
+//         DWT.error(DWT.ERROR_NULL_ARGUMENT);
+//     }
     Point sel = getSelectionRange();
     replaceTextRange(sel.x, sel.y, string);
 }
@@ -6457,7 +6453,6 @@
  * </ul>
  * @exception IllegalArgumentException <ul>
  *   <li>ERROR_INVALID_RANGE when either start or end is outside the valid range (0 <= offset <= getCharCount())</li>
- *   <li>ERROR_NULL_ARGUMENT when ranges is null</li>
  * </ul>
  *
  * @since 2.0
@@ -6467,7 +6462,8 @@
 public void replaceStyleRanges(int start, int length, StyleRange[] ranges) {
     checkWidget();
     if (isListening(LineGetStyle)) return;
-    if (ranges is null) DWT.error(DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (ranges is null) DWT.error(DWT.ERROR_NULL_ARGUMENT);
     setStyleRanges(start, length, null, ranges, false);
 }
 /**
@@ -6500,14 +6496,14 @@
  *   <li>ERROR_INVALID_RANGE when either start or end is outside the valid range (0 <= offset <= getCharCount())</li>
  *   <li>ERROR_INVALID_ARGUMENT when either start or end is inside a multi byte line delimiter.
  *      Splitting a line delimiter for example by inserting text in between the CR and LF and deleting part of a line delimiter is not supported</li>
- *   <li>ERROR_NULL_ARGUMENT when string is null</li>
  * </ul>
  */
 public void replaceTextRange(int start, int length, String text) {
     checkWidget();
-    if (text is null) {
-        DWT.error(DWT.ERROR_NULL_ARGUMENT);
-    }
+    // DWT extension: allow null for zero length string
+//     if (text is null) {
+//         DWT.error(DWT.ERROR_NULL_ARGUMENT);
+//     }
     int contentLength = getCharCount();
     int end = start + length;
     if (start > end || start < 0 || end > contentLength) {
@@ -8095,7 +8091,6 @@
  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
  * </ul>
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT when the list of ranges is null</li>
  *    <li>ERROR_INVALID_RANGE when the last of the style ranges is outside the valid range (> getCharCount())</li>
  * </ul>
  *
@@ -8104,7 +8099,8 @@
 public void setStyleRanges(StyleRange[] ranges) {
     checkWidget();
     if (isListening(LineGetStyle)) return;
-    if (ranges is null) DWT.error(DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (ranges is null) DWT.error(DWT.ERROR_NULL_ARGUMENT);
     setStyleRanges(0, 0, null, ranges, true);
 }
 /**
@@ -8142,15 +8138,13 @@
  *    <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>
  * </ul>
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT when string is null</li>
- * </ul>
  */
 public void setText(String text) {
     checkWidget();
-    if (text is null) {
-        DWT.error(DWT.ERROR_NULL_ARGUMENT);
-    }
+    // DWT extension: allow null for zero length string
+//     if (text is null) {
+//         DWT.error(DWT.ERROR_NULL_ARGUMENT);
+//     }
     Event event = new Event();
     event.start = 0;
     event.end = getCharCount();
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/custom/TableTree.d
--- a/dwt/custom/TableTree.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/custom/TableTree.d	Sun Jun 15 22:32:20 2008 +0200
@@ -764,7 +764,7 @@
  * @param items the array of items
  *
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the array of items is null</li>
+ *    <li>ERROR_NULL_ARGUMENT - if one of the items is null</li>
  *    <li>ERROR_INVALID_ARGUMENT - if one of the item has been disposed</li>
  * </ul>
  * @exception DWTException <ul>
@@ -776,7 +776,8 @@
  */
 public void setSelection (TableTreeItem[] items) {
     checkWidget ();
-    if (items is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (items is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
     int length = items.length;
     if (length is 0 || ((table.getStyle() & DWT.SINGLE) !is 0 && length > 1)) {
         deselectAll();
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/custom/TableTreeItem.d
--- a/dwt/custom/TableTreeItem.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/custom/TableTreeItem.d	Sun Jun 15 22:32:20 2008 +0200
@@ -819,9 +819,6 @@
  * @param index the column number
  * @param text the new text
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the text is null</li>
- * </ul>
  * @exception DWTException <ul>
  *      <li>ERROR_THREAD_INVALID_ACCESS when called from the wrong thread</li>
  *      <li>ERROR_WIDGET_DISPOSED when the widget has been disposed</li>
@@ -829,7 +826,8 @@
  */
 public void setText(int index, String text) {
     checkWidget();
-    if (text is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (text is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
     int columnCount = Math.max(parent.getTable().getColumnCount(), 1);
     if (index < 0 || index >= columnCount) return;
     if (texts.length < columnCount) {
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/dnd/Clipboard.d
--- a/dwt/dnd/Clipboard.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/dnd/Clipboard.d	Sun Jun 15 22:32:20 2008 +0200
@@ -28,7 +28,6 @@
 import dwt.dwthelper.utils;
 
 import tango.core.Thread;
-static import tango.stdc.stringz;
 static import tango.stdc.string;
 
 /**
@@ -563,7 +562,7 @@
         if (pName is null) {
             continue;
         }
-        String buffer = tango.stdc.stringz.fromStringz( pName ).dup;
+        String buffer = fromStringz( pName ).dup;
         OS.g_free (pName);
         result[count++] = "GTKCLIPBOARD "~buffer;
     }
@@ -572,7 +571,7 @@
         if (pName is null) {
             continue;
         }
-        String buffer = tango.stdc.stringz.fromStringz( pName ).dup;
+        String buffer = fromStringz( pName ).dup;
         OS.g_free (pName);
         result[count++] = "GTKPRIMARYCLIPBOARD "~buffer;
     }
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/dnd/FileTransfer.d
--- a/dwt/dnd/FileTransfer.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/dnd/FileTransfer.d	Sun Jun 15 22:32:20 2008 +0200
@@ -89,7 +89,7 @@
         auto uriPtr = OS.g_filename_to_uri(localePtr, null, &error);
         OS.g_free(localePtr);
         if (error !is null || uriPtr is null) continue;
-        String temp = tango.stdc.stringz.fromStringz( uriPtr ).dup;
+        String temp = fromStringz( uriPtr ).dup;
         OS.g_free(uriPtr);
         int newLength = (i > 0) ? buffer.length+separator.length+temp.length :  temp.length;
         String newBuffer = new char[newLength];
@@ -162,7 +162,7 @@
         auto utf8Ptr = OS.g_filename_to_utf8(localePtr, -1, null, null, &error);
         OS.g_free(localePtr);
         if (error !is null || utf8Ptr is null) continue;
-        String buffer = tango.stdc.stringz.fromStringz( utf8Ptr ).dup;
+        String buffer = fromStringz( utf8Ptr ).dup;
         OS.g_free(utf8Ptr);
         String name = buffer;
         String[] newFileNames = new String[]( fileNames.length + 1 );
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/dnd/TextTransfer.d
--- a/dwt/dnd/TextTransfer.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/dnd/TextTransfer.d	Sun Jun 15 22:32:20 2008 +0200
@@ -20,8 +20,6 @@
 import dwt.dnd.DND;
 
 
-static import tango.stdc.stringz;
-
 /**
  * The class <code>TextTransfer</code> provides a platform specific mechanism
  * for converting plain text represented as a java <code>String</code>
@@ -80,7 +78,7 @@
         DND.error(DND.ERROR_INVALID_DATA);
     }
     String string = (cast(ArrayWrapperString)object).array;
-    char* utf8 = tango.stdc.stringz.toStringz(string);
+    char* utf8 = toStringz(string);
     if  (transferData.type is cast(void*) COMPOUND_TEXT_ID) {
         void* encoding;
         int format;
@@ -130,7 +128,7 @@
     char** list;
     int count = OS.gdk_text_property_to_utf8_list(transferData.type, transferData.format, transferData.pValue, transferData.length, &list);
     if (count is 0) return null;
-    String utf8 = tango.stdc.stringz.fromStringz( list[0] ).dup;
+    String utf8 = fromStringz( list[0] ).dup;
     OS.g_strfreev(list);
     return new ArrayWrapperString( utf8 );
 }
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/dnd/Transfer.d
--- a/dwt/dnd/Transfer.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/dnd/Transfer.d	Sun Jun 15 22:32:20 2008 +0200
@@ -1,4 +1,4 @@
-/*******************************************************************************
+/*******************************************************************************
  * Copyright (c) 2000, 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
@@ -19,7 +19,6 @@
 import dwt.internal.gtk.OS;
 import dwt.dnd.TransferData;
 
-static import tango.stdc.stringz;
 
 /**
  * <code>Transfer</code> provides a mechanism for converting between a java
@@ -139,7 +138,7 @@
  */
 public static int registerType(String formatName){
     if (formatName is null) return OS.GDK_NONE;
-    char* buffer = tango.stdc.stringz.toStringz( formatName );
+    char* buffer = toStringz( formatName );
     return cast(int)/*64*/OS.gdk_atom_intern(buffer, false);
 }
 
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/dnd/URLTransfer.d
--- a/dwt/dnd/URLTransfer.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/dnd/URLTransfer.d	Sun Jun 15 22:32:20 2008 +0200
@@ -96,7 +96,7 @@
     if (!isSupportedType(transferData) ||  transferData.pValue is null) return null;
     int size = (transferData.format * transferData.length / 8);
     if (size <= 0) return null;
-    String string = tango.stdc.stringz.fromStringz(cast(char*)transferData.pValue).dup;
+    String string = fromStringz(cast(char*)transferData.pValue).dup;
     int end = string.indexOf('\0');
     return new ArrayWrapperString((end is -1) ? string : string.substring(0, end));
 }
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/dwthelper/utils.d
--- a/dwt/dwthelper/utils.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/dwthelper/utils.d	Sun Jun 15 22:32:20 2008 +0200
@@ -10,7 +10,7 @@
 
 import tango.io.Stdout;
 import tango.io.Print;
-import tango.stdc.stringz;
+static import tango.stdc.stringz;
 static import tango.text.Util;
 static import tango.text.Text;
 import tango.text.Unicode;
@@ -629,6 +629,11 @@
     }
 }
 
+public alias tango.stdc.stringz.toStringz toStringz;
+public alias tango.stdc.stringz.toString16z toString16z;
+public alias tango.stdc.stringz.fromStringz fromStringz;
+public alias tango.stdc.stringz.fromString16z fromString16z;
+
 static String toHex(uint value, bool prefix = true, int radix = 8){
     return tango.text.convert.Integer.toString(
             value,
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/graphics/Device.d
--- a/dwt/graphics/Device.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/graphics/Device.d	Sun Jun 15 22:32:20 2008 +0200
@@ -28,7 +28,6 @@
 import dwt.dwthelper.utils;
 
 import tango.core.Exception;
-import tango.stdc.stringz;
 import tango.io.Stdout;
 
 /**
@@ -590,7 +589,7 @@
         if (debugging) {
             int flags = OS.G_LOG_LEVEL_MASK | OS.G_LOG_FLAG_FATAL | OS.G_LOG_FLAG_RECURSION;
             for (int i=0; i<log_domains.length; i++) {
-                handler_ids [i] = OS.g_log_set_handler (toStringz(log_domains [i]), flags, & logFunction, cast(void*)this);
+                handler_ids [i] = OS.g_log_set_handler (log_domains [i].toStringzValidPtr(), flags, & logFunction, cast(void*)this);
             }
         }
     }
@@ -690,7 +689,7 @@
 public bool loadFont (String path) {
     checkDevice();
     if (path is null) DWT.error (DWT.ERROR_NULL_ARGUMENT);
-    return cast(bool) OS.FcConfigAppFontAddFile (null, toStringz(path));
+    return cast(bool) OS.FcConfigAppFontAddFile (null, path.toStringzValidPtr());
 }
 
 private static extern(C) void logFunction (char* log_domain, int log_level, char* message, void* user_data) {
@@ -791,7 +790,7 @@
     if (xDisplay !is null) {
         for (int i=0; i<handler_ids.length; i++) {
             if (handler_ids [i] !is 0 ) {
-                OS.g_log_remove_handler (toStringz(log_domains [i]), handler_ids [i]);
+                OS.g_log_remove_handler (log_domains [i].toStringzValidPtr(), handler_ids [i]);
                 handler_ids [i] = 0;
             }
         }
@@ -820,7 +819,7 @@
             if (debugging) return;
             for (int i=0; i<handler_ids.length; i++) {
                 if (handler_ids [i] !is 0) {
-                    OS.g_log_remove_handler (toStringz(log_domains [i]), handler_ids [i]);
+                    OS.g_log_remove_handler (log_domains [i].toStringzValidPtr(), handler_ids [i]);
                     handler_ids [i] = 0;
                 }
             }
@@ -830,7 +829,7 @@
             if (debugging) return;
             int flags = OS.G_LOG_LEVEL_MASK | OS.G_LOG_FLAG_FATAL | OS.G_LOG_FLAG_RECURSION;
             for (int i=0; i<log_domains.length; i++) {
-                handler_ids [i] = OS.g_log_set_handler (toStringz(log_domains [i]), flags, & logFunction, cast(void*)this );
+                handler_ids [i] = OS.g_log_set_handler (log_domains [i].toStringzValidPtr(), flags, & logFunction, cast(void*)this );
             }
         }
     }
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/graphics/Font.d
--- a/dwt/graphics/Font.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/graphics/Font.d	Sun Jun 15 22:32:20 2008 +0200
@@ -23,7 +23,6 @@
 import dwt.internal.gtk.OS;
 
 import tango.text.convert.Format;
-import tango.stdc.stringz;
 
 /**
  * Instances of this class manage operating system resources that
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/graphics/GC.d
--- a/dwt/graphics/GC.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/graphics/GC.d	Sun Jun 15 22:32:20 2008 +0200
@@ -45,7 +45,6 @@
 
 import tango.text.convert.Format;
 import tango.stdc.string;
-import tango.stdc.stringz;
 
 
 /**
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/graphics/Image.d
--- a/dwt/graphics/Image.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/graphics/Image.d	Sun Jun 15 22:32:20 2008 +0200
@@ -33,7 +33,6 @@
 
 import tango.text.convert.Format;
 import tango.stdc.string;
-import tango.stdc.stringz;
 
 /**
  * Instances of this class are graphics which have been prepared
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/graphics/ImageData.d
--- a/dwt/graphics/ImageData.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/graphics/ImageData.d	Sun Jun 15 22:32:20 2008 +0200
@@ -444,7 +444,7 @@
 
     int bytesPerLine = (((width * depth + 7) / 8) + (scanlinePad - 1))
         / scanlinePad * scanlinePad;
-    
+
     /*
      * When the image is being loaded from a PNG, we need to use the theoretical minimum
      * number of bytes per line to check whether there is enough data, because the actual
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/graphics/TextLayout.d
--- a/dwt/graphics/TextLayout.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/graphics/TextLayout.d	Sun Jun 15 22:32:20 2008 +0200
@@ -32,7 +32,6 @@
 import dwt.dwthelper.utils;
 
 import tango.text.convert.Format;
-import tango.stdc.stringz;
 import tango.stdc.string;
 import tango.text.convert.Utf;
 import Math = tango.math.Math;
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/internal/Converter.d
--- a/dwt/internal/Converter.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/internal/Converter.d	Sun Jun 15 22:32:20 2008 +0200
@@ -1,4 +1,4 @@
-/*******************************************************************************
+/*******************************************************************************
  * Copyright (c) 2000, 2004 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
@@ -14,10 +14,6 @@
 
 import dwt.dwthelper.utils;
 
-
-//import dwt.internal.gtk.OS;
-import tango.stdc.stringz;
-
 extern(C) {
     struct GError{};
     char*     g_utf16_to_utf8     ( wchar  *str,
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/printing/PrintDialog.d
--- a/dwt/printing/PrintDialog.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/printing/PrintDialog.d	Sun Jun 15 22:32:20 2008 +0200
@@ -28,7 +28,6 @@
 
 import tango.util.Convert;
 import Math = tango.math.Math;
-static import tango.stdc.stringz;
 
 /**
  * Instances of this class allow the user to select
@@ -284,7 +283,7 @@
     if (OS.GTK_VERSION < OS.buildVERSION (2, 10, 0)) {
         return Printer.getDefaultPrinterData();
     } else {
-        char* titleBytes = tango.stdc.stringz.toStringz( getText() );
+        char* titleBytes = toStringz( getText() );
         auto topHandle = getParent().handle;
         while (topHandle !is null && !OS.GTK_IS_WINDOW(topHandle)) {
             topHandle = OS.gtk_widget_get_parent(topHandle);
@@ -309,11 +308,11 @@
             Printer.setScope(settings, printerData.scope_, printerData.startPage, printerData.endPage);
             //TODO: Should we look at printToFile, or driver/name for "Print to File", or both? (see gtk bug 345590)
             if (printerData.printToFile) {
-                char* buffer = tango.stdc.stringz.toStringz(printerData.fileName);
+                char* buffer = toStringz(printerData.fileName);
                 OS.gtk_print_settings_set(settings, OS.GTK_PRINT_SETTINGS_OUTPUT_URI.ptr, buffer);
             }
             if (printerData.driver.equals("GtkPrintBackendFile") && printerData.name.equals("Print to File")) { //$NON-NLS-1$ //$NON-NLS-2$
-                char* buffer = tango.stdc.stringz.toStringz(printerData.fileName);
+                char* buffer = toStringz(printerData.fileName);
                 OS.gtk_print_settings_set(settings, OS.GTK_PRINT_SETTINGS_OUTPUT_URI.ptr, buffer);
             }
             OS.gtk_print_settings_set_n_copies(settings, printerData.copyCount);
@@ -323,7 +322,7 @@
         Printer.setScope(settings, scope_, startPage, endPage);
 
         if (printToFile) {
-            char* buffer = tango.stdc.stringz.toStringz( "Print to File" ); //$NON-NLS-1$
+            char* buffer = toStringz( "Print to File" ); //$NON-NLS-1$
             OS.gtk_print_settings_set_printer(settings, buffer);
         }
         OS.gtk_print_unix_dialog_set_settings(handle, settings);
@@ -392,7 +391,7 @@
                 printToFile = ( data.name.equals("Print to File")); //$NON-NLS-1$
                 if (printToFile) {
                     auto address = OS.gtk_print_settings_get(settings, OS.GTK_PRINT_SETTINGS_OUTPUT_URI.ptr);
-                    data.fileName = tango.stdc.stringz.fromStringz( address).dup;
+                    data.fileName = fromStringz( address).dup;
                 }
 
                 data.scope_ = scope_;
@@ -439,7 +438,7 @@
 }
 
 void GtkPrintSettingsMeth (char* key, char* value) {
-    store( tango.stdc.stringz.fromStringz(key).dup, tango.stdc.stringz.fromStringz(value).dup );
+    store( fromStringz(key).dup, fromStringz(value).dup );
 }
 
 void store(String key, int value) {
@@ -455,7 +454,7 @@
 }
 
 void storeBytes(String key, char* value) {
-    store(key, tango.stdc.stringz.fromStringz(value).dup );
+    store(key, fromStringz(value).dup );
 }
 
 void store(char [] key, String value) {
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/printing/Printer.d
--- a/dwt/printing/Printer.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/printing/Printer.d	Sun Jun 15 22:32:20 2008 +0200
@@ -28,7 +28,6 @@
 import dwt.printing.PrinterData;
 import dwt.dwthelper.utils;
 
-static import tango.stdc.stringz;
 import tango.io.Stdout;
 import tango.util.Convert;
 
@@ -178,10 +177,10 @@
 static PrinterData printerDataFromGtkPrinter(GtkPrinter*  printer) {
     auto backend = OS.gtk_printer_get_backend(printer);
     auto address = OS.G_OBJECT_TYPE_NAME(backend);
-    String backendType =tango.stdc.stringz.fromStringz( address ).dup;
+    String backendType = fromStringz( address ).dup;
 
     address = OS.gtk_printer_get_name (printer);
-    String name =tango.stdc.stringz.fromStringz( address ).dup;
+    String name = fromStringz( address ).dup;
 
     return new PrinterData (backendType, name);
 }
@@ -468,7 +467,7 @@
  */
 public bool startJob(String jobName) {
     checkDevice();
-    char* buffer = tango.stdc.stringz.toStringz(jobName);
+    char* buffer = toStringz(jobName);
     printJob = OS.gtk_print_job_new (buffer, printer, settings, pageSetup);
     if (printJob is null) return false;
     surface = OS.gtk_print_job_get_surface(printJob, null);
@@ -736,11 +735,11 @@
     setScope(settings, data.scope_, data.startPage, data.endPage);
     //TODO: Should we look at printToFile, or driver/name for "Print to File", or both? (see gtk bug 345590)
     if (data.printToFile) {
-        char* buffer = tango.stdc.stringz.toStringz( data.fileName );
+        char* buffer = toStringz( data.fileName );
         OS.gtk_print_settings_set(settings, OS.GTK_PRINT_SETTINGS_OUTPUT_URI.ptr, buffer);
     }
     if (data.driver.equals("GtkPrintBackendFile") && data.name.equals("Print to File")) { //$NON-NLS-1$ //$NON-NLS-2$
-        char* buffer = tango.stdc.stringz.toStringz( data.fileName );
+        char* buffer = toStringz( data.fileName );
         OS.gtk_print_settings_set(settings, OS.GTK_PRINT_SETTINGS_OUTPUT_URI.ptr, buffer);
     }
     OS.gtk_print_settings_set_n_copies(settings, data.copyCount);
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/program/Program.d
--- a/dwt/program/Program.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/program/Program.d	Sun Jun 15 22:32:20 2008 +0200
@@ -24,7 +24,6 @@
 import dwt.dwthelper.utils;
 
 import tango.sys.SharedLib;
-import tango.stdc.stringz;
 import tango.core.Exception;
 import tango.core.Array;
 import tango.text.convert.Format;
@@ -705,9 +704,6 @@
  * @param extension the program extension
  * @return the program or <code>null</code>
  *
- * @exception IllegalArgumentException <ul>
- *      <li>ERROR_NULL_ARGUMENT when extension is null</li>
- *  </ul>
  */
 public static Program findProgram(String extension) {
     return findProgram(Display.getCurrent(), extension);
@@ -718,7 +714,8 @@
  *       become public and the original method above can be deprecated.
  */
 static Program findProgram(Display display, String extension) {
-    if (extension is null) DWT.error(DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (extension is null) DWT.error(DWT.ERROR_NULL_ARGUMENT);
     if (extension.length is 0) return null;
     if (extension.charAt(0) !is '.') extension = "." ~ extension;
     int desktop = getDesktop(display);
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Button.d
--- a/dwt/widgets/Button.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Button.d	Sun Jun 15 22:32:20 2008 +0200
@@ -26,7 +26,6 @@
 import dwt.widgets.TypedListener;
 import dwt.widgets.Decorations;
 
-import tango.stdc.stringz;
 import tango.io.Stdout;
 
 /**
@@ -782,9 +781,6 @@
  * </p>
  * @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>
@@ -792,7 +788,8 @@
  */
 public void setText (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 ((style & DWT.ARROW) !is 0) return;
     text = string;
     char [] chars = fixMnemonic (string);
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/ColorDialog.d
--- a/dwt/widgets/ColorDialog.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/ColorDialog.d	Sun Jun 15 22:32:20 2008 +0200
@@ -12,8 +12,6 @@
  *******************************************************************************/
 module dwt.widgets.ColorDialog;
 
-
-
 import dwt.DWT;
 import dwt.DWTException;
 import dwt.graphics.PaletteData;
@@ -23,7 +21,7 @@
 import dwt.widgets.Shell;
 import dwt.widgets.Display;
 
-import tango.stdc.stringz;
+import dwt.dwthelper.utils;
 
 /**
  * Instances of this class allow the user to select a color
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Combo.d
--- a/dwt/widgets/Combo.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Combo.d	Sun Jun 15 22:32:20 2008 +0200
@@ -26,7 +26,6 @@
 import dwt.widgets.TypedListener;
 
 import dwt.dwthelper.utils;
-import tango.stdc.stringz;
 import Math = tango.math.Math;
 
 /**
@@ -138,9 +137,6 @@
  *
  * @param string the new item
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string 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>
@@ -150,7 +146,8 @@
  */
 public void add (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);
     add (string, items.length);
 }
 
@@ -167,7 +164,6 @@
  * @param index the index for the item
  *
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
  *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list (inclusive)</li>
  * </ul>
  * @exception DWTException <ul>
@@ -179,7 +175,8 @@
  */
 public void add (String string, int index) {
     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 (!(0 <= index && index <= items.length)) {
         error (DWT.ERROR_INVALID_RANGE);
     }
@@ -188,7 +185,7 @@
     newItems [index] = string;
     System.arraycopy (items, index, newItems, index + 1, items.length - index);
     items = newItems;
-    char* buffer = toStringz(string);
+    char* buffer = string.toStringzValidPtr();
     if (OS.GTK_VERSION >= OS.buildVERSION (2, 4, 0)) {
         OS.gtk_combo_box_insert_text (handle, index, buffer);
         if ((style & DWT.RIGHT_TO_LEFT) !is 0 && popupHandle !is null) {
@@ -1402,9 +1399,6 @@
  * @param string the search item
  * @return the index of the item
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string 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>
@@ -1426,9 +1420,6 @@
  * @param start the zero-relative index at which to begin the search
  * @return the index of the item
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string 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>
@@ -1436,10 +1427,11 @@
  */
 public int indexOf (String string, int start) {
     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 (!(0 <= start && start < items.length)) return -1;
     for (int i=start; i<items.length; i++) {
-        if (string==/*eq*/items [i]) return i;
+        if (string.equals (items [i])) return i;
     }
     return -1;
 }
@@ -1612,7 +1604,6 @@
  * @param string the item to remove
  *
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
  *    <li>ERROR_INVALID_ARGUMENT - if the string is not found in the list</li>
  * </ul>
  * @exception DWTException <ul>
@@ -1622,7 +1613,8 @@
  */
 public void remove (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);
     int index = indexOf (string, 0);
     if (index is -1) error (DWT.ERROR_INVALID_ARGUMENT);
     remove (index);
@@ -1845,7 +1837,6 @@
  *
  * @exception IllegalArgumentException <ul>
  *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)</li>
- *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
  * </ul>
  * @exception DWTException <ul>
  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
@@ -1854,12 +1845,13 @@
  */
 public void setItem (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 (!(0 <= index && index < items.length)) {
         error (DWT.ERROR_INVALID_ARGUMENT);
     }
     items [index] = string;
-    char* buffer = toStringz(string);
+    char* buffer = string.toStringzValidPtr();
     if (OS.GTK_VERSION >= OS.buildVERSION (2, 4, 0)) {
         OS.gtk_combo_box_remove_text (handle, index);
         OS.gtk_combo_box_insert_text (handle, index, buffer);
@@ -1883,7 +1875,6 @@
  * @param items the array of items
  *
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the items array is null</li>
  *    <li>ERROR_INVALID_ARGUMENT - if an item in the items array is null</li>
  * </ul>
  * @exception DWTException <ul>
@@ -1893,7 +1884,8 @@
  */
 public void setItems (String [] items) {
     checkWidget();
-    if (items is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (items is null) error (DWT.ERROR_NULL_ARGUMENT);
     for (int i=0; i<items.length; i++) {
         if (items [i] is null) error (DWT.ERROR_INVALID_ARGUMENT);
     }
@@ -1907,7 +1899,7 @@
         }
         for (int i = 0; i < items.length; i++) {
             String string = items [i];
-            char* buffer = toStringz(string);
+            char* buffer = string.toStringzValidPtr();
             OS.gtk_combo_box_insert_text (handle, i, buffer);
             if ((style & DWT.RIGHT_TO_LEFT) !is 0 && popupHandle !is null) {
                 display.doSetDirectionProc(popupHandle, OS.GTK_TEXT_DIR_RTL);
@@ -1922,7 +1914,7 @@
         int i = 0;
         while (i < items.length) {
             String string = items [i];
-            char * buffer = toStringz(string);
+            char * buffer = string.toStringzValidPtr();
             auto item = OS.gtk_list_item_new_with_label (buffer);
             auto label = OS.gtk_bin_get_child (item);
             setForegroundColor (label, color);
@@ -2038,9 +2030,6 @@
  *
  * @param string the new text
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string 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>
@@ -2048,7 +2037,8 @@
  */
 public void setText (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 ((style & DWT.READ_ONLY) !is 0) {
         int index = indexOf (string);
         if (index is -1) return;
@@ -2075,7 +2065,7 @@
         string = verifyText (string, 0, cast(int)/*64*/OS.g_utf8_strlen (ptr, -1));
         if (string is null) return;
     }
-    auto buffer = toStringz(string);
+    auto buffer = string.toStringzValidPtr();
     if (OS.GTK_VERSION >= OS.buildVERSION (2, 4, 0)) {
         OS.g_signal_handlers_block_matched (handle, OS.G_SIGNAL_MATCH_DATA, 0, 0, null, null, udCHANGED);
     }
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Control.d
--- a/dwt/widgets/Control.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Control.d	Sun Jun 15 22:32:20 2008 +0200
@@ -57,7 +57,6 @@
 import dwt.accessibility.Accessible;
 
 import Math = tango.math.Math;
-import tango.stdc.stringz;
 import tango.core.Thread;
 import tango.io.Stdout;
 
@@ -2596,7 +2595,7 @@
         char* buffer = null;
         if (toolTipText !is null && toolTipText.length !is 0) {
             char [] chars = fixMnemonic (toolTipText, false);
-            buffer = tango.stdc.stringz.toStringz(chars);
+            buffer = toStringz(chars);
         }
         auto toolHandle = getShell().handle;
         OS.gtk_widget_set_tooltip_text (toolHandle, buffer);
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/CoolBar.d
--- a/dwt/widgets/CoolBar.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/CoolBar.d	Sun Jun 15 22:32:20 2008 +0200
@@ -12,8 +12,6 @@
  *******************************************************************************/
 module dwt.widgets.CoolBar;
 
-
-
 import dwt.DWT;
 import dwt.DWTException;
 import dwt.graphics.Color;
@@ -26,6 +24,7 @@
 import dwt.widgets.Event;
 import dwt.widgets.Control;
 import dwt.widgets.Listener;
+
 import dwt.dwthelper.utils;
 
 /**
@@ -950,7 +949,8 @@
     return indices;
 }
 void setItemOrder (int[] itemOrder) {
-    if (itemOrder is null) error(DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (itemOrder is null) error(DWT.ERROR_NULL_ARGUMENT);
     int count = originalItems.length;
     if (itemOrder.length !is count) error(DWT.ERROR_INVALID_ARGUMENT);
 
@@ -992,7 +992,8 @@
     return sizes;
 }
 void setItemSizes (Point[] sizes) {
-    if (sizes is null) error(DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (sizes is null) error(DWT.ERROR_NULL_ARGUMENT);
     CoolItem[] items = getItems();
     if (sizes.length !is items.length) error(DWT.ERROR_INVALID_ARGUMENT);
     for (int i = 0; i < items.length; i++) {
@@ -1143,7 +1144,6 @@
  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
  * </ul>
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if item order or sizes is null</li>
  *    <li>ERROR_INVALID_ARGUMENT - if item order or sizes is not the same length as the number of items</li>
  * </ul>
  */
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/CoolItem.d
--- a/dwt/widgets/CoolItem.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/CoolItem.d	Sun Jun 15 22:32:20 2008 +0200
@@ -12,8 +12,6 @@
  *******************************************************************************/
 module dwt.widgets.CoolItem;
 
-
-
 import dwt.DWT;
 import dwt.DWTException;
 import dwt.events.SelectionEvent;
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Decorations.d
--- a/dwt/widgets/Decorations.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Decorations.d	Sun Jun 15 22:32:20 2008 +0200
@@ -596,7 +596,6 @@
  * @param images the new image array
  *
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the array of images is null</li>
  *    <li>ERROR_INVALID_ARGUMENT - if one of the images is null or has been disposed</li>
  * </ul>
  * @exception DWTException <ul>
@@ -608,7 +607,8 @@
  */
 public void setImages (Image [] images) {
     checkWidget ();
-    if (images is null) error (DWT.ERROR_INVALID_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (images is null) error (DWT.ERROR_INVALID_ARGUMENT);
     for (int i = 0; i < images.length; i++) {
         if (images [i] is null || images [i].isDisposed ()) error (DWT.ERROR_INVALID_ARGUMENT);
     }
@@ -709,9 +709,6 @@
  *
  * @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>
@@ -719,7 +716,8 @@
  */
 public void setText (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);
     text = string;
 }
 
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Dialog.d
--- a/dwt/widgets/Dialog.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Dialog.d	Sun Jun 15 22:32:20 2008 +0200
@@ -256,16 +256,14 @@
  *
  * @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>
  * </ul>
  */
 public void setText (String string) {
-    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);
     title = string;
 }
 
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/DirectoryDialog.d
--- a/dwt/widgets/DirectoryDialog.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/DirectoryDialog.d	Sun Jun 15 22:32:20 2008 +0200
@@ -24,7 +24,6 @@
 import dwt.widgets.Display;
 
 static import tango.io.FileConst;
-static import tango.stdc.stringz;
 static import tango.text.Util;
 
 /**
@@ -131,7 +130,7 @@
     }
 }
 String openChooserDialog () {
-    char* titleBytes = tango.stdc.stringz.toStringz(title);
+    char* titleBytes = toStringz(title);
     auto shellHandle = parent.topHandle ();
     auto handle = OS.gtk_file_chooser_dialog_new2 (
         titleBytes,
@@ -154,7 +153,7 @@
         else{
             p = filterPath;
         }
-        char* buffer = tango.stdc.stringz.toStringz(p);
+        char* buffer = toStringz(p);
         /*
         * Bug in GTK. GtkFileChooser may crash on GTK versions 2.4.10 to 2.6
         * when setting a file name that is not a true canonical path.
@@ -167,7 +166,7 @@
         }
     }
     if (message.length > 0) {
-        char* buffer = tango.stdc.stringz.toStringz(message);
+        char* buffer = toStringz(message);
         auto box = OS.gtk_hbox_new (false, 0);
         if (box is null) error (DWT.ERROR_NO_HANDLES);
         auto label = OS.gtk_label_new (buffer);
@@ -220,7 +219,7 @@
     return answer;
 }
 String openClassicDialog () {
-    char* titleBytes = tango.stdc.stringz.toStringz(title);
+    char* titleBytes = toStringz(title);
     auto handle = OS.gtk_file_selection_new (titleBytes);
     if (parent !is null) {
         auto shellHandle = parent.topHandle ();
@@ -237,7 +236,7 @@
         if (path.length > 0 && path[ $-1 .. $ ] != SEPARATOR ) {
             path ~= SEPARATOR;
         }
-        char* fileNamePtr = OS.g_filename_from_utf8 (tango.stdc.stringz.toStringz(path), -1, null, null, null);
+        char* fileNamePtr = OS.g_filename_from_utf8 (toStringz(path), -1, null, null, null);
         OS.gtk_file_selection_set_filename (handle, fileNamePtr);
         OS.g_free (fileNamePtr);
     }
@@ -247,7 +246,7 @@
     OS.gtk_widget_hide (selection.file_list);
     OS.gtk_widget_hide (fileListParent);
     if (message.length > 0) {
-        auto labelHandle = OS.gtk_label_new (tango.stdc.stringz.toStringz(message));
+        auto labelHandle = OS.gtk_label_new (toStringz(message));
         OS.gtk_label_set_line_wrap (labelHandle, true);
         OS.gtk_misc_set_alignment (labelHandle, 0.0f, 0.0f);
         OS.gtk_container_add (selection.main_vbox, labelHandle);
@@ -321,12 +320,10 @@
  *
  * @param string the message
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
- * </ul>
  */
 public void setMessage (String string) {
-    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);
     message = string.dup;
 }
 }
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Display.d
--- a/dwt/widgets/Display.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Display.d	Sun Jun 15 22:32:20 2008 +0200
@@ -44,7 +44,6 @@
 import dwt.widgets.Widget;
 
 import tango.stdc.string;
-import tango.stdc.stringz;
 import dwt.dwthelper.utils;
 import dwt.dwthelper.Runnable;
 
@@ -1597,9 +1596,6 @@
  * @param key the name of the property
  * @return the value of the property or null if it has not been set
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the key is null</li>
- * </ul>
  * @exception DWTException <ul>
  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
  *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
@@ -1610,7 +1606,8 @@
  */
 public Object getData (String key) {
     checkDevice ();
-    if (key is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (key is null) error (DWT.ERROR_NULL_ARGUMENT);
     if (key.equals (DISPATCH_EVENT_KEY)) {
         return new ArrayWrapperInt(dispatchEvents);
     }
@@ -3522,9 +3519,6 @@
  * @param key the name of the property
  * @param value the new value for the property
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the key is null</li>
- * </ul>
  * @exception DWTException <ul>
  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
  *    <li>ERROR_DEVICE_DISPOSED - if the receiver has been disposed</li>
@@ -3535,9 +3529,10 @@
  */
 public void setData (String key, Object value) {
     checkDevice ();
-    if (key is null) error (DWT.ERROR_NULL_ARGUMENT);
-
-    if (key==/*eq*/ DISPATCH_EVENT_KEY) {
+    // DWT extension: allow null for zero length string
+    //if (key is null) error (DWT.ERROR_NULL_ARGUMENT);
+
+    if (key.equals (DISPATCH_EVENT_KEY)) {
         ArrayWrapperInt wrappedValue;
         if (value is null || (null !is (wrappedValue=cast(ArrayWrapperInt)value))) {
             dispatchEvents = wrappedValue.array;
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/ExpandItem.d
--- a/dwt/widgets/ExpandItem.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/ExpandItem.d	Sun Jun 15 22:32:20 2008 +0200
@@ -31,7 +31,6 @@
 import dwt.widgets.Event;
 
 import Math = tango.math.Math;
-static import tango.stdc.stringz;
 
 /**
  * Instances of this class represent a selectable user interface object
@@ -606,7 +605,7 @@
 public override void setText (String string) {
     super.setText (string);
     if (OS.GTK_VERSION >= OS.buildVERSION (2, 4, 0)) {
-        OS.gtk_label_set_text (labelHandle, tango.stdc.stringz.toStringz(string));
+        OS.gtk_label_set_text (labelHandle, toStringz(string));
     } else {
         redraw ();
     }
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/FileDialog.d
--- a/dwt/widgets/FileDialog.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/FileDialog.d	Sun Jun 15 22:32:20 2008 +0200
@@ -149,7 +149,7 @@
     if (filter !is null) {
         auto filterNamePtr = OS.gtk_file_filter_get_name (filter);
         if (filterNamePtr !is null) {
-            String filterName = tango.stdc.stringz.fromStringz(filterNamePtr).dup;
+            String filterName = fromStringz(filterNamePtr).dup;
             //OS.g_free (filterNamePtr); //GTK owns this pointer - do not free
             for (int i = 0; i < filterExtensions.length; i++) {
                 if (filterNames.length > 0) {
@@ -179,7 +179,7 @@
     GtkFileSelection* selection = cast(GtkFileSelection*)handle;
     auto entry = selection.selection_entry;
     auto entryText = OS.gtk_entry_get_text (entry);
-    String txt = tango.stdc.stringz.fromStringz( entryText );
+    String txt = fromStringz( entryText );
     if (txt.length is 0) {
         auto fileList = selection.file_list;
         auto listSelection = OS.gtk_tree_view_get_selection (fileList);
@@ -345,7 +345,7 @@
     }
 }
 String openChooserDialog () {
-    char* titleBytes = tango.stdc.stringz.toStringz( title );
+    char* titleBytes = toStringz( title );
     int action = (style & DWT.SAVE) !is 0 ?
         OS.GTK_FILE_CHOOSER_ACTION_SAVE :
         OS.GTK_FILE_CHOOSER_ACTION_OPEN;
@@ -394,7 +394,7 @@
     return answer;
 }
 String openClassicDialog () {
-    char* titleBytes = tango.stdc.stringz.toStringz( title );
+    char* titleBytes = toStringz( title );
     handle = OS.gtk_file_selection_new (titleBytes);
     if (parent !is null) {
         auto shellHandle = parent.topHandle ();
@@ -456,7 +456,7 @@
                 stringBuffer.append (SEPARATOR);
             }
             stringBuffer.append (fileName);
-        char* buffer = tango.stdc.stringz.toStringz( stringBuffer.toString ());
+        char* buffer = toStringz( stringBuffer.toString ());
             /*
             * Bug in GTK. GtkFileChooser may crash on GTK versions 2.4.10 to 2.6
             * when setting a file name that is not a true canonical path.
@@ -468,7 +468,7 @@
                 OS.g_free (ptr);
             }
         } else {
-            char* buffer = tango.stdc.stringz.toStringz( stringBuffer.toString () );
+            char* buffer = toStringz( stringBuffer.toString () );
             /*
             * Bug in GTK. GtkFileChooser may crash on GTK versions 2.4.10 to 2.6
             * when setting a file name that is not a true canonical path.
@@ -483,7 +483,7 @@
     } else {
         if (fileName.length > 0) {
             if (fileName[0] is SEPARATOR) {
-                char* buffer = tango.stdc.stringz.toStringz(fileName);
+                char* buffer = toStringz(fileName);
 
                 /*
                 * Bug in GTK. GtkFileChooser may crash on GTK versions 2.4.10 to 2.6
@@ -499,7 +499,7 @@
         }
     }
     if ((style & DWT.SAVE) !is 0 && fileName.length > 0) {
-        char* buffer = tango.stdc.stringz.toStringz(fileName);
+        char* buffer = toStringz(fileName);
         OS.gtk_file_chooser_set_current_name (handle, buffer);
     }
     if ((style & DWT.SAVE) !is 0) {
@@ -516,23 +516,23 @@
         if (filterExtensions [i] !is null) {
             auto filter = OS.gtk_file_filter_new ();
             if (filterNames.length > i && filterNames [i] !is null) {
-                char* name = tango.stdc.stringz.toStringz(filterNames [i]);
+                char* name = toStringz(filterNames [i]);
                 OS.gtk_file_filter_set_name (filter, name);
             } else {
-                char* name = tango.stdc.stringz.toStringz(filterExtensions [i]);
+                char* name = toStringz(filterExtensions [i]);
                 OS.gtk_file_filter_set_name (filter, name);
             }
             int start = 0;
             int index = tango.text.Util.locate( filterExtensions [i], EXTENSION_SEPARATOR );
             while (index !is filterExtensions [i].length ) {
                 String current = filterExtensions [i][ start .. index ];
-                char* filterString = tango.stdc.stringz.toStringz(current);
+                char* filterString = toStringz(current);
                 OS.gtk_file_filter_add_pattern (filter, filterString);
                 start = index + 1;
                 index = tango.text.Util.locate( filterExtensions [i], EXTENSION_SEPARATOR, start);
             }
             String current = filterExtensions [i][ start .. $ ];
-            char* filterString = tango.stdc.stringz.toStringz(current);
+            char* filterString = toStringz(current);
             OS.gtk_file_filter_add_pattern (filter, filterString);
             OS.gtk_file_chooser_add_filter (handle, filter);
             if (i is filterIndex) {
@@ -567,7 +567,7 @@
         stringBuffer.append (fileName);
     }
     fullPath = stringBuffer.toString ();
-    auto fileNamePtr = OS.g_filename_from_utf8 (tango.stdc.stringz.toStringz( fullPath ), -1, null, null, null);
+    auto fileNamePtr = OS.g_filename_from_utf8 (toStringz( fullPath ), -1, null, null, null);
     OS.gtk_file_selection_set_filename (handle, fileNamePtr);
     OS.g_free (fileNamePtr);
 
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/FontDialog.d
--- a/dwt/widgets/FontDialog.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/FontDialog.d	Sun Jun 15 22:32:20 2008 +0200
@@ -12,8 +12,6 @@
  *******************************************************************************/
 module dwt.widgets.FontDialog;
 
-
-
 import dwt.DWT;
 import dwt.DWTException;
 import dwt.graphics.Font;
@@ -25,7 +23,7 @@
 import dwt.widgets.Shell;
 import dwt.widgets.Display;
 
-static import tango.stdc.stringz;
+import dwt.dwthelper.utils;
 
 /**
  * Instances of this class allow the user to select a font
@@ -143,7 +141,7 @@
 public FontData open () {
     GtkWidget* handle;
     char* titleBytes;
-    titleBytes = tango.stdc.stringz.toStringz(title);
+    titleBytes = toStringz(title);
     Display display = parent !is null ? parent.getDisplay (): Display.getCurrent ();
     handle = OS.gtk_font_selection_dialog_new (titleBytes);
     if (parent !is null) {
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Group.d
--- a/dwt/widgets/Group.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Group.d	Sun Jun 15 22:32:20 2008 +0200
@@ -22,7 +22,6 @@
 import dwt.widgets.Composite;
 
 import Math = tango.math.Math;
-import tango.stdc.stringz;
 
 /**
  * Instances of this class provide an etched border
@@ -272,9 +271,6 @@
  * </p>
  * @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>
@@ -282,7 +278,8 @@
  */
 public void setText (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);
     text = string;
     char [] chars = fixMnemonic (string);
     OS.gtk_label_set_text_with_mnemonic (cast(GtkLabel*)labelHandle, chars.toStringzValidPtr());
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/IME.d
--- a/dwt/widgets/IME.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/IME.d	Sun Jun 15 22:32:20 2008 +0200
@@ -116,7 +116,7 @@
     if (textPtr !is null && inComposition) {
         int length = OS.strlen (textPtr);
         if (length !is 0) {
-            char [] chars = tango.stdc.stringz.fromStringz(textPtr).dup;
+            char [] chars = fromStringz(textPtr).dup;
             Event event = new Event();
             event.detail = DWT.COMPOSITION_CHANGED;
             event.start = startOffset;
@@ -148,7 +148,7 @@
     char [] chars = null;
     if (preeditString !is null) {
         int length = OS.strlen (preeditString);
-        chars = tango.stdc.stringz.fromStringz(preeditString).dup;
+        chars = fromStringz(preeditString).dup;
         if (pangoAttrs !is null) {
             int count = 0;
             auto iterator = OS.pango_attr_list_get_iterator (pangoAttrs );
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Item.d
--- a/dwt/widgets/Item.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Item.d	Sun Jun 15 22:32:20 2008 +0200
@@ -172,9 +172,6 @@
  *
  * @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>
@@ -182,7 +179,8 @@
  */
 public void setText (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);
     text = string.dup;
 }
 
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Label.d
--- a/dwt/widgets/Label.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Label.d	Sun Jun 15 22:32:20 2008 +0200
@@ -562,9 +562,6 @@
  *
  * @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>
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Link.d
--- a/dwt/widgets/Link.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Link.d	Sun Jun 15 22:32:20 2008 +0200
@@ -708,9 +708,6 @@
  *
  * @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>
@@ -718,7 +715,8 @@
  */
 public void setText (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 (string.equals(text)) return;
     text = string;
     layout.setText (parse (string));
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/List.d
--- a/dwt/widgets/List.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/List.d	Sun Jun 15 22:32:20 2008 +0200
@@ -26,7 +26,6 @@
 import dwt.dwthelper.utils;
 
 import Math = tango.math.Math;
-import tango.stdc.stringz;
 import tango.text.convert.Integer;
 
 /**
@@ -96,9 +95,6 @@
  *
  * @param string the new item
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string 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>
@@ -108,8 +104,9 @@
  */
 public void add (String string) {
     checkWidget();
-    if (string is null) error (DWT.ERROR_NULL_ARGUMENT);
-    char* buffer = toStringz(string);
+    // DWT extension: allow null for zero length string
+    //if (string is null) error (DWT.ERROR_NULL_ARGUMENT);
+    char* buffer = string.toStringzValidPtr();
     GtkTreeIter iter;
     OS.gtk_list_store_append (cast(GtkListStore*)modelHandle, &iter);
     OS.gtk_list_store_set1 (cast(GtkListStore*)modelHandle, &iter, TEXT_COLUMN, buffer);
@@ -128,7 +125,6 @@
  * @param index the index for the item
  *
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
  *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list (inclusive)</li>
  * </ul>
  * @exception DWTException <ul>
@@ -140,12 +136,13 @@
  */
 public void add (String string, int index) {
     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);
     int count = OS.gtk_tree_model_iter_n_children (cast(GtkTreeStore*)modelHandle, null);
     if (!(0 <= index && index <= count)) {
         error (DWT.ERROR_INVALID_RANGE);
     }
-    char* buffer = toStringz(string);
+    char* buffer = string.toStringzValidPtr();
     GtkTreeIter iter;
     /*
     * Feature in GTK.  It is much faster to append to a list store
@@ -335,9 +332,6 @@
  *
  * @param indices the array of indices for the items to deselect
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the set of indices 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>
@@ -345,7 +339,8 @@
  */
 public void deselect (int [] indices) {
     checkWidget();
-    if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
     GtkTreeIter iter;
     int count = OS.gtk_tree_model_iter_n_children (cast(GtkTreeStore*)modelHandle, null);
     auto selection = OS.gtk_tree_view_get_selection (cast(GtkTreeView*)handle);
@@ -830,9 +825,6 @@
  * @param string the search item
  * @return the index of the item
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string 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>
@@ -854,9 +846,6 @@
  * @param start the zero-relative index at which to start the search
  * @return the index of the item
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string 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>
@@ -864,10 +853,11 @@
  */
 public int indexOf (String string, int start) {
     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);
     String [] items = getItems ();
     for (int i=start; i<items.length; i++) {
-        if (items [i] ==/*eq*/ (string)) return i;
+        if (items [i].equals (string)) return i;
     }
     return -1;
 }
@@ -979,7 +969,6 @@
  * @param string the item to remove
  *
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
  *    <li>ERROR_INVALID_ARGUMENT - if the string is not found in the list</li>
  * </ul>
  * @exception DWTException <ul>
@@ -989,7 +978,8 @@
  */
 public void remove (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);
     int index = indexOf (string, 0);
     if (index is -1) error (DWT.ERROR_INVALID_ARGUMENT);
     remove (index);
@@ -1003,7 +993,6 @@
  *
  * @exception IllegalArgumentException <ul>
  *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)</li>
- *    <li>ERROR_NULL_ARGUMENT - if the indices array is null</li>
  * </ul>
  * @exception DWTException <ul>
  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
@@ -1012,7 +1001,8 @@
  */
 public void remove (int [] indices) {
     checkWidget();
-    if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
     if (indices.length is 0) return;
     int [] newIndices = new int []( indices.length );
     System.arraycopy (indices, 0, newIndices, 0, indices.length);
@@ -1162,9 +1152,6 @@
  *
  * @param indices the array of indices for the items to select
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the array of indices 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>
@@ -1174,7 +1161,8 @@
  */
 public void select (int [] indices) {
     checkWidget ();
-    if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
     int length = indices.length;
     if (length is 0 || ((style & DWT.SINGLE) !is 0 && length > 1)) return;
     GtkTreeIter iter;
@@ -1278,7 +1266,6 @@
  *
  * @exception IllegalArgumentException <ul>
  *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)</li>
- *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
  * </ul>
  * @exception DWTException <ul>
  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
@@ -1287,13 +1274,14 @@
  */
 public void setItem (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 (!(0 <= index && index < OS.gtk_tree_model_iter_n_children (cast(GtkTreeStore*)modelHandle, null)))  {
         error (DWT.ERROR_INVALID_RANGE);
     }
     GtkTreeIter iter;
     OS.gtk_tree_model_iter_nth_child (cast(GtkTreeStore*)modelHandle, &iter, null, index);
-    char* buffer = toStringz(string);
+    char* buffer = string.toStringzValidPtr();
     OS.gtk_list_store_set1 (cast(GtkListStore*)modelHandle, &iter, TEXT_COLUMN, buffer);
 }
 
@@ -1303,7 +1291,6 @@
  * @param items the array of items
  *
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the items array is null</li>
  *    <li>ERROR_INVALID_ARGUMENT - if an item in the items array is null</li>
  * </ul>
  * @exception DWTException <ul>
@@ -1399,9 +1386,6 @@
  *
  * @param indices the indices of the items to select
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the array of indices 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>
@@ -1412,7 +1396,8 @@
  */
 public void setSelection(int[] indices) {
     checkWidget ();
-    if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
     deselectAll ();
     int length = indices.length;
     if (length is 0 || ((style & DWT.SINGLE) !is 0 && length > 1)) return;
@@ -1433,9 +1418,6 @@
  *
  * @param items the array of items
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the array of items 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>
@@ -1447,7 +1429,8 @@
  */
 public void setSelection (String [] items) {
     checkWidget ();
-    if (items is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (items is null) error (DWT.ERROR_NULL_ARGUMENT);
     deselectAll ();
     int length = items.length;
     if (length is 0 || ((style & DWT.SINGLE) !is 0 && length > 1)) return;
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Menu.d
--- a/dwt/widgets/Menu.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Menu.d	Sun Jun 15 22:32:20 2008 +0200
@@ -28,8 +28,6 @@
 import dwt.widgets.Shell;
 import dwt.dwthelper.utils;
 
-import tango.stdc.stringz;
-
 /**
  * Instances of this class are user interface objects that contain
  * menu items.
@@ -191,7 +189,7 @@
         if (getItemCount () !is 0) {
             if ((OS.GTK_VERSION >=  OS.buildVERSION (2, 8, 0))) {
                 /*
-                * Feature in GTK. ON_TOP shells will send out 
+                * Feature in GTK. ON_TOP shells will send out
                 * DWT.Deactivate whenever a context menu is shown.
                 * The fix is to prevent the menu from taking focus
                 * when it is being shown in an ON_TOP shell.
@@ -720,7 +718,7 @@
     int reqy = this.y;
     if (reqy + requisition.height > screenHeight) {
         reqy = Math.max (0, reqy - requisition.height);
-    } 
+    }
     int screenWidth = OS.gdk_screen_width ();
     int reqx = this.x;
     if ((style & DWT.RIGHT_TO_LEFT) !is 0) {
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/MenuItem.d
--- a/dwt/widgets/MenuItem.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/MenuItem.d	Sun Jun 15 22:32:20 2008 +0200
@@ -30,7 +30,6 @@
 import dwt.widgets.Display;
 
 import dwt.dwthelper.utils;
-import tango.stdc.stringz;
 
 /**
  * Instances of this class represent a selectable user interface object
@@ -828,9 +827,6 @@
  *
  * @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>
@@ -840,7 +836,8 @@
  */
 public override void setText (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 ((style & DWT.SEPARATOR) !is 0) return;
     if (text.equals(string)) return;
     super.setText (string);
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/MessageBox.d
--- a/dwt/widgets/MessageBox.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/MessageBox.d	Sun Jun 15 22:32:20 2008 +0200
@@ -23,7 +23,6 @@
 import dwt.widgets.Shell;
 import dwt.widgets.Display;
 
-import tango.stdc.stringz;
 
 /**
  * Instances of this class are used to inform or warn the user.
@@ -131,12 +130,10 @@
  *
  * @param string the message
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string is null</li>
- * </ul>
  */
 public void setMessage (String string) {
-    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);
     message = string;
 }
 
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Scrollable.d
--- a/dwt/widgets/Scrollable.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Scrollable.d	Sun Jun 15 22:32:20 2008 +0200
@@ -23,7 +23,6 @@
 import dwt.widgets.Widget;
 
 import tango.stdc.string;
-import tango.stdc.stringz;
 
 /**
  * This class is the abstract superclass of all classes which
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Shell.d
--- a/dwt/widgets/Shell.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Shell.d	Sun Jun 15 22:32:20 2008 +0200
@@ -43,7 +43,6 @@
 import dwt.widgets.Widget;
 
 import Unicode = tango.text.Unicode;
-import tango.stdc.stringz;
 
 /**
  * Instances of this class represent the "windows"
@@ -1927,7 +1926,7 @@
         char * buffer = null;
         if (string !is null && string.length > 0) {
             char [] chars = fixMnemonic (string, false);
-            buffer = tango.stdc.stringz.toStringz( chars );
+            buffer = toStringz( chars );
         }
         OS.gtk_widget_set_tooltip_text (rootWidget, null);
         /*
@@ -1966,7 +1965,7 @@
         char* buffer = null;
         if (string !is null && string.length > 0) {
             char [] chars = fixMnemonic (string, false);
-            buffer = tango.stdc.stringz.toStringz( chars );
+            buffer = toStringz( chars );
         }
         if (tooltipsHandle is null) {
             tooltipsHandle = cast(GtkWidget*)OS.gtk_tooltips_new ();
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Spinner.d
--- a/dwt/widgets/Spinner.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Spinner.d	Sun Jun 15 22:32:20 2008 +0200
@@ -26,7 +26,6 @@
 import dwt.events.ModifyListener;
 import dwt.events.VerifyListener;
 
-import tango.stdc.stringz;
 import tango.util.Convert;
 import dwt.dwthelper.utils;
 
@@ -483,7 +482,7 @@
 public String getText () {
     checkWidget ();
     auto str = OS.gtk_entry_get_text (handle);
-    return tango.stdc.stringz.fromStringz(str).dup;
+    return fromStringz(str).dup;
 }
 
 public int getTextLimit () {
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/TabFolder.d
--- a/dwt/widgets/TabFolder.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/TabFolder.d	Sun Jun 15 22:32:20 2008 +0200
@@ -696,9 +696,6 @@
  *
  * @param items the array of items
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the items array 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>
@@ -706,7 +703,8 @@
  */
 public void setSelection (TabItem [] items) {
     checkWidget();
-    if (items is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (items is null) error (DWT.ERROR_NULL_ARGUMENT);
     if (items.length is 0) {
         setSelection (-1, false);
     } else {
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/TabItem.d
--- a/dwt/widgets/TabItem.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/TabItem.d	Sun Jun 15 22:32:20 2008 +0200
@@ -26,8 +26,6 @@
 import dwt.widgets.TabFolder;
 import dwt.widgets.ImageList;
 
-static import tango.stdc.stringz;
-
 /**
  * Instances of this class represent a selectable user interface object
  * corresponding to a tab for a page in a tab folder.
@@ -331,9 +329,6 @@
  *
  * @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>
@@ -342,7 +337,8 @@
  */
 public override void setText (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);
     super.setText (string);
     char [] chars = fixMnemonic (string);
     OS.gtk_label_set_text_with_mnemonic (labelHandle, chars.toStringzValidPtr() );
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Table.d
--- a/dwt/widgets/Table.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Table.d	Sun Jun 15 22:32:20 2008 +0200
@@ -40,7 +40,6 @@
 import dwt.widgets.TypedListener;
 import dwt.dwthelper.utils;
 
-static import tango.stdc.stringz;
 import tango.util.Convert;
 
 /**
@@ -476,7 +475,6 @@
  *
  * @exception IllegalArgumentException <ul>
  *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)</li>
- *    <li>ERROR_NULL_ARGUMENT - if the indices array is null</li>
  * </ul>
  * @exception DWTException <ul>
  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
@@ -490,7 +488,8 @@
  */
 public void clear (int [] indices) {
     checkWidget ();
-    if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
     if (indices.length is 0) return;
     for (int i=0; i<indices.length; i++) {
         if (!(0 <= indices [i] && indices [i] < itemCount)) {
@@ -941,9 +940,6 @@
  *
  * @param indices the array of indices for the items to deselect
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the set of indices 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>
@@ -951,7 +947,8 @@
  */
 public void deselect (int [] indices) {
     checkWidget();
-    if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
     bool fixColumn = showFirstColumn ();
     auto selection = OS.gtk_tree_view_get_selection (handle);
     OS.g_signal_handlers_block_matched (selection, OS.G_SIGNAL_MATCH_DATA, 0, 0, null, null, udCHANGED);
@@ -2129,7 +2126,7 @@
 public bool isSelected (int index) {
     checkWidget();
     auto selection = OS.gtk_tree_view_get_selection (handle);
-    char* buffer = tango.stdc.stringz.toStringz( to!(String)(index));
+    char* buffer = toStringz( to!(String)(index));
     auto path = OS.gtk_tree_path_new_from_string (buffer);
     bool answer = cast(bool)OS.gtk_tree_selection_path_is_selected (selection, path);
     OS.gtk_tree_path_free (path);
@@ -2310,7 +2307,6 @@
  *
  * @exception IllegalArgumentException <ul>
  *    <li>ERROR_INVALID_RANGE - if the index is not between 0 and the number of elements in the list minus 1 (inclusive)</li>
- *    <li>ERROR_NULL_ARGUMENT - if the indices array is null</li>
  * </ul>
  * @exception DWTException <ul>
  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
@@ -2319,7 +2315,8 @@
  */
 public void remove (int [] indices) {
     checkWidget();
-    if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
     if (indices.length is 0) return;
     int [] newIndices = new int [indices.length];
     System.arraycopy (indices, 0, newIndices, 0, indices.length);
@@ -2755,9 +2752,6 @@
  *
  * @param indices the array of indices for the items to select
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the array of indices 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>
@@ -2767,7 +2761,8 @@
  */
 public void select (int [] indices) {
     checkWidget ();
-    if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
     int length = indices.length;
     if (length is 0 || ((style & DWT.SINGLE) !is 0 && length > 1)) return;
     bool fixColumn = showFirstColumn ();
@@ -2880,7 +2875,6 @@
  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
  * </ul>
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the item order is null</li>
  *    <li>ERROR_INVALID_ARGUMENT - if the item order is not the same length as the number of items</li>
  * </ul>
  *
@@ -2893,7 +2887,8 @@
  */
 public void setColumnOrder (int [] order) {
     checkWidget ();
-    if (order is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (order is null) error (DWT.ERROR_NULL_ARGUMENT);
     if (columnCount is 0) {
         if (order.length > 0) error (DWT.ERROR_INVALID_ARGUMENT);
         return;
@@ -3169,9 +3164,6 @@
  *
  * @param indices the indices of the items to select
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the array of indices 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>
@@ -3182,7 +3174,8 @@
  */
 public void setSelection (int [] indices) {
     checkWidget ();
-    if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (indices is null) error (DWT.ERROR_NULL_ARGUMENT);
     deselectAll ();
     int length = indices.length;
     if (length is 0 || ((style & DWT.SINGLE) !is 0 && length > 1)) return;
@@ -3233,7 +3226,6 @@
  * @param items the array of items
  *
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the array of items is null</li>
  *    <li>ERROR_INVALID_ARGUMENT - if one of the items has been disposed</li>
  * </ul>
  * @exception DWTException <ul>
@@ -3247,7 +3239,8 @@
  */
 public void setSelection (TableItem [] items) {
     checkWidget ();
-    if (items is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (items is null) error (DWT.ERROR_NULL_ARGUMENT);
     bool fixColumn = showFirstColumn ();
     deselectAll ();
     int length = items.length;
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/TableColumn.d
--- a/dwt/widgets/TableColumn.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/TableColumn.d	Sun Jun 15 22:32:20 2008 +0200
@@ -610,7 +610,8 @@
 
 public override void setText (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);
     super.setText (string);
     char [] chars = fixMnemonic (string);
     OS.gtk_label_set_text_with_mnemonic (labelHandle, chars.toStringzValidPtr() );
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/TableItem.d
--- a/dwt/widgets/TableItem.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/TableItem.d	Sun Jun 15 22:32:20 2008 +0200
@@ -204,7 +204,7 @@
     int modelIndex = parent.columnCount is 0 ? Table.FIRST_COLUMN : parent.columns [index].modelIndex;
     OS.gtk_tree_model_get1 (parent.modelHandle, handle, modelIndex + Table.CELL_TEXT, &ptr);
     if (ptr is null) return "";
-    char[] buffer = tango.stdc.stringz.fromStringz( cast(char*)ptr).dup;
+    char[] buffer = fromStringz( cast(char*)ptr).dup;
     OS.g_free (ptr);
     return buffer;
 }
@@ -1287,7 +1287,7 @@
     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 ? Table.FIRST_COLUMN : parent.columns [index].modelIndex;
     OS.gtk_list_store_set1 (parent.modelHandle, handle, modelIndex + Table.CELL_TEXT, buffer);
     /*
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Text.d
--- a/dwt/widgets/Text.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Text.d	Sun Jun 15 22:32:20 2008 +0200
@@ -28,7 +28,6 @@
 import dwt.widgets.Composite;
 
 import Math = tango.math.Math;
-import tango.stdc.stringz;
 static import tango.stdc.string;
 
 /**
@@ -291,9 +290,6 @@
  *
  * @param string the string to be appended
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string 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>
@@ -301,7 +297,8 @@
  */
 public void append (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 ((style & DWT.SINGLE) !is 0) {
         int dummy = -1;
         OS.gtk_editable_insert_text (cast(GtkEditable*)handle, string.ptr, string.length, &dummy );
@@ -1395,9 +1392,6 @@
  *
  * @param string the string
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string is <code>null</code></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>
@@ -1405,7 +1399,8 @@
  */
 public void insert (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 ((style & DWT.SINGLE) !is 0) {
         int start, end;
         OS.gtk_editable_get_selection_bounds (cast(GtkEditable*)handle, &start, &end);
@@ -1695,7 +1690,8 @@
  */
 public void setMessage (String message) {
     checkWidget ();
-    if (message is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (message is null) error (DWT.ERROR_NULL_ARGUMENT);
     this.message = message;
 }
 
@@ -1871,9 +1867,6 @@
  *
  * @param string the new text
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the string 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>
@@ -1881,7 +1874,8 @@
  */
 public void setText (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);
     /*
     * Feature in gtk.  When text is set in gtk, separate events are fired for the deletion and
     * insertion of the text.  This is not wrong, but is inconsistent with other platforms.  The
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/ToolItem.d
--- a/dwt/widgets/ToolItem.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/ToolItem.d	Sun Jun 15 22:32:20 2008 +0200
@@ -31,8 +31,6 @@
 import dwt.widgets.Event;
 import dwt.widgets.ImageList;
 
-import tango.stdc.stringz;
-
 /**
  * Instances of this class represent a selectable user interface object
  * that represents a button in a tool bar.
@@ -976,9 +974,6 @@
  *
  * @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>
@@ -986,7 +981,8 @@
  */
 public override void setText (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 ((style & DWT.SEPARATOR) !is 0) return;
     super.setText (string);
     if (labelHandle is null) return;
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/ToolTip.d
--- a/dwt/widgets/ToolTip.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/ToolTip.d	Sun Jun 15 22:32:20 2008 +0200
@@ -28,8 +28,6 @@
 import dwt.widgets.Event;
 import dwt.widgets.Display;
 
-import tango.stdc.stringz;
-
 /**
  * Instances of this class represent popup windows that are used
  * to inform or warn the user.
@@ -175,9 +173,9 @@
                 0, 5+t];
             if ((parent.style & DWT.MIRRORED) !is 0) {
                 x -= w - 36;
-                polyline[12] = w-36; 
-                polyline[14] = w-16; 
-                polyline[16] = w-15; 
+                polyline[12] = w-36;
+                polyline[14] = w-16;
+                polyline[16] = w-15;
                 borderPolygon[12] = w-35;
                 borderPolygon[14] = borderPolygon[16]  = w-16;
             }
@@ -691,9 +689,6 @@
  *
  * @param string the new message
  *
- * @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>
@@ -701,13 +696,14 @@
  */
 public void setMessage (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);
     message = string;
     if ((style & DWT.BALLOON) is 0) return;
     if (layoutMessage !is null) OS.g_object_unref (layoutMessage);
     layoutMessage = null;
     if (message.length !is 0) {
-        layoutMessage = OS.gtk_widget_create_pango_layout (handle, toStringz( message ));
+        layoutMessage = OS.gtk_widget_create_pango_layout (handle, message.toStringzValidPtr());
         if (OS.GTK_VERSION >= OS.buildVERSION (2, 4, 0)) {
             OS.pango_layout_set_auto_dir (layoutMessage, false);
         }
@@ -721,9 +717,6 @@
  *
  * @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>
@@ -731,13 +724,14 @@
  */
 public void setText (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);
     text = string;
     if ((style & DWT.BALLOON) is 0) return;
     if (layoutText !is null) OS.g_object_unref (layoutText);
     layoutText = null;
     if (text.length !is 0) {
-        layoutText = OS.gtk_widget_create_pango_layout (handle, toStringz(text));
+        layoutText = OS.gtk_widget_create_pango_layout (handle, text.toStringzValidPtr());
         if (OS.GTK_VERSION >= OS.buildVERSION (2, 4, 0)) {
             OS.pango_layout_set_auto_dir (layoutText, false);
         }
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Tracker.d
--- a/dwt/widgets/Tracker.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Tracker.d	Sun Jun 15 22:32:20 2008 +0200
@@ -955,7 +955,7 @@
  * @param rectangles the bounds of the rectangles to be drawn
  *
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the set of rectangles is null or contains a null rectangle</li>
+ *    <li>ERROR_NULL_ARGUMENT - if the set of rectangles contains a null rectangle</li>
  * </ul>
  * @exception DWTException <ul>
  *    <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
@@ -964,7 +964,8 @@
  */
 public void setRectangles (Rectangle [] rectangles) {
     checkWidget();
-    if (rectangles is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (rectangles is null) error (DWT.ERROR_NULL_ARGUMENT);
     int length = rectangles.length;
     this.rectangles = new Rectangle [length];
     for (int i = 0; i < length; i++) {
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/TrayItem.d
--- a/dwt/widgets/TrayItem.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/TrayItem.d	Sun Jun 15 22:32:20 2008 +0200
@@ -29,7 +29,6 @@
 import dwt.internal.gtk.OS;
 
 import Math = tango.math.Math;
-import tango.stdc.stringz;
 import tango.util.Convert;
 
 /**
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Tree.d
--- a/dwt/widgets/Tree.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Tree.d	Sun Jun 15 22:32:20 2008 +0200
@@ -2820,7 +2820,6 @@
  *    <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
  * </ul>
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the item order is null</li>
  *    <li>ERROR_INVALID_ARGUMENT - if the item order is not the same length as the number of items</li>
  * </ul>
  *
@@ -2833,7 +2832,8 @@
  */
 public void setColumnOrder (int [] order) {
     checkWidget ();
-    if (order is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (order is null) error (DWT.ERROR_NULL_ARGUMENT);
     if (columnCount is 0) {
         if (order.length > 0) error (DWT.ERROR_INVALID_ARGUMENT);
         return;
@@ -2973,7 +2973,6 @@
  * @param items the array of items
  *
  * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the array of items is null</li>
  *    <li>ERROR_INVALID_ARGUMENT - if one of the items has been disposed</li>
  * </ul>
  * @exception DWTException <ul>
@@ -2985,7 +2984,8 @@
  */
 public void setSelection (TreeItem [] items) {
     checkWidget ();
-    if (items is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (items is null) error (DWT.ERROR_NULL_ARGUMENT);
     deselectAll ();
     int length = items.length;
     if (length is 0 || ((style & DWT.SINGLE) !is 0 && length > 1)) return;
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/TreeColumn.d
--- a/dwt/widgets/TreeColumn.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/TreeColumn.d	Sun Jun 15 22:32:20 2008 +0200
@@ -30,7 +30,6 @@
 import dwt.widgets.TypedListener;
 
 import Math = tango.math.Math;
-static import tango.stdc.stringz;
 
 /**
  * Instances of this class represent a column in a tree widget.
@@ -605,7 +604,8 @@
 
 public override void setText (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);
     super.setText (string);
     char [] chars = fixMnemonic (string);
     OS.gtk_label_set_text_with_mnemonic (labelHandle, chars.toStringzValidPtr());
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/TreeItem.d
--- 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);
diff -r 8bca790583c3 -r 5a30aa9820f3 dwt/widgets/Widget.d
--- a/dwt/widgets/Widget.d	Sun Jun 08 15:11:48 2008 +0200
+++ b/dwt/widgets/Widget.d	Sun Jun 15 22:32:20 2008 +0200
@@ -25,7 +25,6 @@
 import dwt.widgets.Listener;
 import dwt.widgets.TypedListener;
 
-import tango.stdc.stringz;
 import tango.stdc.string;
 import tango.core.Thread;
 
@@ -575,9 +574,6 @@
  * @param   key the name of the property
  * @return the value of the property or null if it has not been set
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the key 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>
@@ -587,7 +583,8 @@
  */
 public Object getData (String key) {
     checkWidget();
-    if (key is null) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (key is null) error (DWT.ERROR_NULL_ARGUMENT);
     if ((state & KEYED_DATA) !is 0) {
         Object[] table = (cast(ArrayWrapperObject) data).array;
         for (int i=1; i<table.length; i+=2) {
@@ -1423,9 +1420,6 @@
  * @param key the name of the property
  * @param value the new value for the property
  *
- * @exception IllegalArgumentException <ul>
- *    <li>ERROR_NULL_ARGUMENT - if the key 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>
@@ -1435,14 +1429,15 @@
  */
 public void setData (String key, Object value) {
     checkWidget();
-    if (key.length is 0) error (DWT.ERROR_NULL_ARGUMENT);
+    // DWT extension: allow null for zero length string
+    //if (key is null) error (DWT.ERROR_NULL_ARGUMENT);
     int index = 1;
     Object [] table = null;
     if ((state & KEYED_DATA) !is 0) {
         table = (cast(ArrayWrapperObject) data).array;
         while (index < table.length) {
             String tablekey = (cast(ArrayWrapperString)table[index]).array;
-            if (key ==/*eq*/ tablekey ) break;
+            if (key.equals (tablekey) ) break;
             index += 2;
         }
     }