catched an exception with invalid pointers (http://community.sharpdevelop.net/forums/thread/8728.aspx)

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/branches/2.0@1492 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/IndexPad.cs

@@ -169,6 +169,8 @@ namespace HtmlHelp2
 		{
 			if (!this.controlIsEnabled) return;
 			
+			try
+			{
 				searchTerm.Text                       = "";
 				searchTerm.Items.Clear();
 				indexControl.IndexData                = HtmlHelp2Environment.GetIndex(HtmlHelp2Environment.CurrentFilterQuery);
@@ -176,6 +178,15 @@ namespace HtmlHelp2
 				HtmlHelp2Environment.BuildFilterList(filterCombobox);
 				filterCombobox.SelectedIndexChanged  += new EventHandler(FilterChanged);
 			}
+			catch
+			{
+				LoggingService.Error("Help 2.0: cannot connect to IHxIndex interface (Index)");
+				indexControl.Enabled = false;
+				indexControl.BackColor = SystemColors.ButtonFace;
+				filterCombobox.Enabled = false;
+				searchTerm.Enabled = false;
+			}
+		}
 
 		private void FilterChanged(object sender, EventArgs e)
 		{

src/AddIns/Misc/HtmlHelp2/Project/src/BaseControls/TocPad.cs

@@ -205,11 +205,21 @@ namespace HtmlHelp2
 		{
 			if (!this.controlIsEnabled) return;
 
+			try
+			{
 				tocControl.Hierarchy                 = HtmlHelp2Environment.GetTocHierarchy(HtmlHelp2Environment.CurrentFilterQuery);
 				filterCombobox.SelectedIndexChanged -= new EventHandler(this.FilterChanged);
 				HtmlHelp2Environment.BuildFilterList(filterCombobox);
 				filterCombobox.SelectedIndexChanged += new EventHandler(this.FilterChanged);
 			}
+			catch
+			{
+				LoggingService.Error("Help 2.0: cannot connect to IHxHierarchy interface (Contents)");
+				tocControl.Enabled = false;
+				tocControl.BackColor = SystemColors.ButtonFace;
+				filterCombobox.Enabled = false;
+			}
+		}
 
 		private void FilterChanged(object sender, EventArgs e)
 		{

src/AddIns/Misc/HtmlHelp2/Project/src/Service/HtmlHelp2Service.cs

@@ -201,36 +201,18 @@ namespace HtmlHelp2.Environment
 		}
 
 		public static IHxHierarchy GetTocHierarchy(string filterQuery)
-		{
-			try
 		{
 			IHxHierarchy defaultToc =
 				(IHxHierarchy)session.GetNavigationInterface("!DefaultTOC", filterQuery, ref TocGuid);
 			return defaultToc;
 		}
-			catch
-			{
-				LoggingService.Error("Help 2.0: cannot connect to IHxHierarchy interface (Contents)");
-				return null;
-			}
-		}
 
 		public static IHxIndex GetIndex(string filterQuery)
-		{
-			try
 		{
 			IHxIndex defaultIndex =
-					(IHxIndex)session.GetNavigationInterface("!DefaultKeywordIndex",
-					                                         filterQuery,
-					                                         ref IndexGuid);
+				(IHxIndex)session.GetNavigationInterface("!DefaultKeywordIndex", filterQuery, ref IndexGuid);
 			return defaultIndex;
 		}
-			catch
-			{
-				LoggingService.Error("Help 2.0: cannot connect to IHxIndex interface (Index)");
-				return null;
-			}
-		}
 
 		public static void BuildFilterList(ComboBox filterCombobox)
 		{