From 24561ad59c092f245264135cb24895b3dab1da26 Mon Sep 17 00:00:00 2001
From: Rickard Karlsson <rickard.karlsson@sogeti.se>
Date: Tue, 5 Nov 2013 12:17:28 +0100
Subject: [PATCH] Ugly hack to fix Error 121 when NERDTree is the active window
 and clicking on the command line below another window.

---
 lib/nerdtree/key_map.vim | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/nerdtree/key_map.vim b/lib/nerdtree/key_map.vim
index 8645765..e237076 100644
--- a/lib/nerdtree/key_map.vim
+++ b/lib/nerdtree/key_map.vim
@@ -79,6 +79,9 @@ endfunction
 "If a keymap has the scope of "all" then it will be called if no other keymap
 "is found for a:key and the scope.
 function! s:KeyMap.Invoke(key)
+    if !exists('b:NERDTreeRoot')
+        return {}
+    endif
     let node = g:NERDTreeFileNode.GetSelected()
     if !empty(node)