Fixed :cd not changing to home dir

content/bookmarks.js

@@ -173,10 +173,14 @@ vimperator.Bookmarks = function () //{{{
         },
 
         isBookmarked: function(url)
+        {
+            try
             {
                 var uri = ioService.newURI(url, null, null);
                 var count = {};
                 bookmarksService.getBookmarkIdsForURI(uri, count);
+            }
+            catch (e) { return false; }
 
             return count.value > 0;
         },

content/commands.js

@@ -737,7 +737,10 @@ vimperator.Commands = function () //{{{
     commandManager.add(new vimperator.Command(["cd", "chd[ir]"],
         function (args)
         {
-            if (!args || vimperator.io.setCurrentDirectory(args))
+            if (!args)
+                args = "~";
+
+            if (vimperator.io.setCurrentDirectory(args))
                 vimperator.echo(vimperator.io.getCurrentDirectory());
         },
         {