[f-spot] Add comma at the end of the comma separated list

[Stephen Shaw <sshaw src gnome org>]

commit e48a90bf5e5cdab34f137e039c350ef34bd220d4
Author: Paul Wellner Bou <paul p wbou de>
Date:   Sun Sep 16 00:33:49 2012 +0200

    Add comma at the end of the comma separated list
    
    Typing t should add a comma at the end of the comma separated list,
    not at first position.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=683888

 src/Clients/MainApp/FSpot.Widgets/TagEntry.cs |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/src/Clients/MainApp/FSpot.Widgets/TagEntry.cs b/src/Clients/MainApp/FSpot.Widgets/TagEntry.cs
index 3902c0e..c64f735 100644
--- a/src/Clients/MainApp/FSpot.Widgets/TagEntry.cs
+++ b/src/Clients/MainApp/FSpot.Widgets/TagEntry.cs
@@ -119,8 +119,11 @@ namespace FSpot.Widgets
 
 		private void AppendComma ()
 		{
-			if (Text.Length != 0 && !Text.Trim ().EndsWith (","))
-				InsertText (", ");
+			if (Text.Length != 0 && !Text.Trim ().EndsWith (",")) {
+				int pos = Text.Length;
+				InsertText (", ", ref pos);
+				Position = Text.Length;
+			}
 		}
 
 		public string [] GetTypedTagNames ()