Fixed SD2-782: Null reference when adding existing item/new folder to project

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/branches/2.0@1349 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/Main/Base/Project/Src/Gui/Components/ExtTreeView/ExtTreeView.cs

@@ -249,6 +249,20 @@ namespace ICSharpCode.SharpDevelop.Gui
 			}
 		}
 		
+		bool canClearSelection = true;
+		
+		/// <summary>
+		/// Gets/Sets whether the user can clear the selection by clicking in the empty area.
+		/// </summary>
+		public bool CanClearSelection {
+			get {
+				return canClearSelection;
+			}
+			set {
+				canClearSelection = value;
+			}
+		}
+		
 		protected override void OnMouseDown(MouseEventArgs e)
 		{
 			base.OnMouseDown(e);
@@ -258,7 +272,9 @@ namespace ICSharpCode.SharpDevelop.Gui
 					SelectedNode = node;
 				}
 			} else {
-				SelectedNode = null;
+				if (canClearSelection) {
+					SelectedNode = null;
+				}
 			}
 		}
 		

src/Main/Base/Project/Src/Gui/Pads/ProjectBrowser/Commands/ReferenceFolderNodeCommands.cs

@@ -117,7 +117,7 @@ namespace ICSharpCode.SharpDevelop.Project.Commands
 	{
 		public override void Run()
 		{
-			AbstractProjectBrowserTreeNode node = Owner as AbstractProjectBrowserTreeNode;
+			AbstractProjectBrowserTreeNode node = ProjectBrowserPad.Instance.SelectedNode;
 			if (node != null && node.Project != null) {
 				using (AddWebReferenceDialog refDialog = new AddWebReferenceDialog(node.Project)) {
 					refDialog.NamespacePrefix = node.Project.RootNamespace;
@@ -152,7 +152,8 @@ namespace ICSharpCode.SharpDevelop.Project.Commands
 			} else if (node is ReferenceFolder && node.Parent != null && node.Parent is ProjectNode) {
 				webReferencesNode = AddWebReferenceToProjectNode((ProjectNode)node.Parent, webReference);
 			} else {
-				LoggingService.Error("AddWebReferenceToProjectBrowser: Selected node type is not handled.");
+				LoggingService.Warn("AddWebReferenceToProjectBrowser: Selected node type is not handled.");
+				AddWebReferenceToProjectBrowser(node.Parent as AbstractProjectBrowserTreeNode, webReference);
 			}
 			
 			if (webReferencesNode != null) {

src/Main/Base/Project/Src/Gui/Pads/ProjectBrowser/ProjectBrowserControl.cs

@@ -62,6 +62,7 @@ namespace ICSharpCode.SharpDevelop.Project
 		public ProjectBrowserControl()
 		{
 			InitializeComponent();
+			treeView.CanClearSelection = false;
 			treeView.BeforeSelect   += TreeViewBeforeSelect;
 			treeView.AfterExpand    += TreeViewAfterExpand;
 			FileService.FileRenamed += FileServiceFileRenamed;