Fixed SD2-685: Pads must have an icon

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/branches/2.0@1425 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/AddIns/Misc/FiletypeRegisterer/Project/Src/RegisterFiletypesCommand.cs

@@ -84,12 +84,20 @@ namespace ICSharpCode.FiletypeRegisterer {
 		
 		public static bool IsRegisteredFileType(string extension)
 		{
-			using (RegistryKey key = Registry.ClassesRoot.OpenSubKey("." + extension)) {
-				if (key != null)
-					return true;
+			try {
+				using (RegistryKey key = Registry.ClassesRoot.OpenSubKey("." + extension)) {
+					if (key != null)
+						return true;
+				}
+			} catch (System.Security.SecurityException) {
+				// registry access might be denied
 			}
-			using (RegistryKey key = Registry.CurrentUser.OpenSubKey("Software\\Classes\\." + extension)) {
-				return key != null;
+			try {
+				using (RegistryKey key = Registry.CurrentUser.OpenSubKey("Software\\Classes\\." + extension)) {
+					return key != null;
+				}
+			} catch (System.Security.SecurityException) {
+				return false;
 			}
 		}
 		
@@ -135,7 +143,7 @@ namespace ICSharpCode.FiletypeRegisterer {
 			UnRegisterFiletype(extension, Registry.ClassesRoot);
 			try {
 				UnRegisterFiletype(extension, Registry.CurrentUser.CreateSubKey("Software\\Classes"));
-			} catch {}
+			} catch {} // catch CreateSubKey(Software\Classes)-exceptions
 			try {
 				SHChangeNotify(SHCNE_ASSOCCHANGED, SHCNF_IDLIST, IntPtr.Zero, IntPtr.Zero);
 			} catch {}

src/Main/Base/Project/Src/Commands/MenuItemBuilders.cs

@@ -353,7 +353,7 @@ namespace ICSharpCode.SharpDevelop.Commands
 				this.padDescriptor = padDescriptor;
 				Text = StringParser.Parse(padDescriptor.Title);
 				
-				if (padDescriptor.Icon != null) {
+				if (!string.IsNullOrEmpty(padDescriptor.Icon)) {
 					base.Image = IconService.GetBitmap(padDescriptor.Icon);
 				}
 				

src/Main/Base/Project/Src/Gui/Workbench/Layouts/SdiWorkspaceLayout.cs

@@ -429,7 +429,7 @@ namespace ICSharpCode.SharpDevelop.Gui
 			Properties properties = (Properties)PropertyService.Get("Workspace.ViewMementos", new Properties());
 			
 			PadContentWrapper newContent = new PadContentWrapper(content);
-			if (content.Icon != null) {
+			if (!string.IsNullOrEmpty(content.Icon)) {
 				newContent.Icon = IconService.GetIcon(content.Icon);
 			}
 			newContent.Text = StringParser.Parse(content.Title);

src/Main/Base/Project/Src/Internal/Doozers/PadDescriptor.cs

@@ -29,8 +29,8 @@ namespace ICSharpCode.Core
 		}
 		
 		/// <summary>
-		/// Returns the icon bitmap resource name of the pad. May be null, if the pad has no
-		/// icon defined.
+		/// Returns the icon bitmap resource name of the pad. May be an empty string
+		/// if the pad has no icon defined.
 		/// </summary>
 		public string Icon {
 			get {