From 2924ab207162ca18cf5844d00b351ade1b5122f6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Adamczak?= <lukasz@czak.pl>
Date: Wed, 22 Jun 2016 13:59:49 +0200
Subject: [PATCH] Verify we haven't reached root when traversing cascade

---
 autoload/nerdtree/ui_glue.vim | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/autoload/nerdtree/ui_glue.vim b/autoload/nerdtree/ui_glue.vim
index 4cbfb38..2aa3bec 100644
--- a/autoload/nerdtree/ui_glue.vim
+++ b/autoload/nerdtree/ui_glue.vim
@@ -187,17 +187,17 @@ endfunction
 " closes the parent dir of the current node
 function! s:closeCurrentDir(node)
     let parent = a:node.parent
+    while g:NERDTreeCascadeOpenSingleChildDir && !parent.isRoot()
+        let childNodes = parent.getVisibleChildren()
+        if len(childNodes) == 1 && childNodes[0].path.isDirectory
+            let parent = parent.parent
+        else
+            break
+        endif
+    endwhile
     if parent ==# {} || parent.isRoot()
         call nerdtree#echo("cannot close tree root")
     else
-        while g:NERDTreeCascadeOpenSingleChildDir && !parent.parent.isRoot()
-            let childNodes = parent.getVisibleChildren()
-            if len(childNodes) == 1 && childNodes[0].path.isDirectory
-                let parent = parent.parent
-            else
-                break
-            endif
-        endwhile
         call parent.close()
         call b:NERDTree.render()
         call parent.putCursorHere(0, 0)