switch to version 3.1.1

previously the code didnt take &hidden (it assumed it was set) into
account when determining if splitting was needed when using the o
mapping on a file node

doc/NERD_tree.txt

@@ -211,6 +211,7 @@ x.......Close the current nodes parent...........................|NERDTree-x|
 X.......Recursively close all children of the current node.......|NERDTree-X|
 e.......Edit the current dif.....................................|NERDTree-e|
 
+<CR>...............same as |NERDTree-o|.
 double-click.......same as the |NERDTree-o| map.
 middle-click.......same as |NERDTree-i| for files, same as
                    |NERDTree-e| for dirs.
@@ -221,8 +222,8 @@ P.......Jump to the root node....................................|NERDTree-P|
 p.......Jump to current nodes parent.............................|NERDTree-p|
 K.......Jump up inside directories at the current tree depth.....|NERDTree-K|
 J.......Jump down inside directories at the current tree depth...|NERDTree-J|
-<C-j>...Jump down to the next sibling of the current directory...|NERDTree-c-j|
-<C-k>...Jump up to the previous sibling of the current directory.|NERDTree-c-k|
+<C-J>...Jump down to the next sibling of the current directory...|NERDTree-C-J|
+<C-K>...Jump up to the previous sibling of the current directory.|NERDTree-C-K|
 
 C.......Change the tree root to the selected dir.................|NERDTree-C|
 u.......Move the tree root up one directory......................|NERDTree-u|
@@ -430,16 +431,16 @@ If the cursor is already on the last node then do the following:
     * go to the last child of that node
 
 ------------------------------------------------------------------------------
-                                                                *NERDTree-c-j*
-Default key: <C-j>
+                                                                *NERDTree-C-J*
+Default key: <C-J>
 Map option: NERDTreeMapJumpNextSibling
 Applies to: files and directories.
 
 Jump to the next sibling of the selected node.
 
 ------------------------------------------------------------------------------
-                                                                *NERDTree-c-k*
-Default key: <C-k>
+                                                                *NERDTree-C-K*
+Default key: <C-K>
 Map option: NERDTreeMapJumpPrevSibling
 Applies to: files and directories.
 
@@ -497,6 +498,14 @@ Applies to: files and directories.
 
 Display the filesystem menu. See |NERDTreeFilesysMenu| for details.
 
+------------------------------------------------------------------------------
+                                                                 *NERDTree-cd*
+Default key: cd
+Map option: NERDTreeMapChdir
+Applies to: files and directories.
+
+Change vims current working directory to that of the selected node.
+
 ------------------------------------------------------------------------------
                                                                   *NERDTree-I*
 Default key: I
@@ -679,7 +688,7 @@ If set to 1, the NERD tree window will center around the cursor if it moves to
 within |'NERDTreeAutoCenterThreshold'| lines of the top/bottom of the window.
 
 This is ONLY done in response to tree navigation mappings,
-i.e. |NERDTree-J| |NERDTree-K| |NERDTree-C-J| |NERDTree-c-K| |NERDTree-p|
+i.e. |NERDTree-J| |NERDTree-K| |NERDTree-C-J| |NERDTree-C-K| |NERDTree-p|
 |NERDTree-P|
 
 The centering is done with a |zz| operation.
@@ -742,7 +751,7 @@ Values: 0 or 1.
 Default: 1.
 
 If set to 1, the current cursor line in the NERD tree buffer will be
-highlighted. This is done using the |cursorline| option.
+highlighted. This is done using the |'cursorline'| option.
 
 ------------------------------------------------------------------------------
                                                        *'NERDTreeHijackNetrw'*
@@ -988,6 +997,15 @@ The latest dev versions are on github
 ==============================================================================
 6. Changelog                                               *NERDTreeChangelog*
 
+3.1.1
+    - fix a bug where a non-listed no-name buffer was getting created every
+      time the tree windows was created, thanks to Derek Wyatt and owen1
+    - make <CR> behave the same as the 'o' mapping
+    - some helptag fixes in the doc, thanks strull
+    - fix a bug when using :set nohidden and opening a file where the previous
+      buf was modified. Thanks iElectric
+    - other minor fixes
+
 3.1.0
     New features:
     - add mappings to open files in a vsplit, see :help NERDTree-s and :help

plugin/NERD_tree.vim

@@ -2,7 +2,7 @@
 " File:        NERD_tree.vim
 " Description: vim global plugin that provides a nice tree explorer
 " Maintainer:  Martin Grenfell <martin_grenfell at msn dot com>
-" Last Change: 27 Jan, 2009
+" Last Change: 7 Jun, 2009
 " License:     This program is free software. It comes without any warranty,
 "              to the extent permitted by applicable law. You can redistribute
 "              it and/or modify it under the terms of the Do What The Fuck You
@@ -10,7 +10,7 @@
 "              See http://sam.zoy.org/wtfpl/COPYING for more details.
 "
 " ============================================================================
-let s:NERD_tree_version = '3.1.0'
+let s:NERD_tree_version = '3.1.1'
 
 " SECTION: Script init stuff {{{1
 "============================================================
@@ -154,7 +154,7 @@ command! -n=? -complete=dir -bar NERDTree :call s:initNerdTree('<args>')
 command! -n=? -complete=dir -bar NERDTreeToggle :call s:toggle('<args>')
 command! -n=0 -bar NERDTreeClose :call s:closeTreeIfOpen()
 command! -n=1 -complete=customlist,s:completeBookmarks -bar NERDTreeFromBookmark call s:initNerdTree('<args>')
-command! -n=0 -complete=customlist,s:completeNERDTreeMirrors -bar NERDTreeMirror call s:initNerdTreeMirror()
+command! -n=0 -bar NERDTreeMirror call s:initNerdTreeMirror()
 " SECTION: Auto commands {{{1
 "============================================================
 augroup NERDTree
@@ -796,12 +796,12 @@ function! s:TreeFileNode.open()
         call s:exec(winnr . "wincmd w")
 
     else
-        if !s:isWindowUsable(winnr("#")) && s:firstNormalWindow() ==# -1
+        if !s:isWindowUsable(winnr("#")) && s:firstUsableWindow() ==# -1
             call self.openSplit()
         else
             try
                 if !s:isWindowUsable(winnr("#"))
-                    call s:exec(s:firstNormalWindow() . "wincmd w")
+                    call s:exec(s:firstUsableWindow() . "wincmd w")
                 else
                     call s:exec('wincmd p')
                 endif
@@ -2355,12 +2355,13 @@ function! s:createTreeWin()
     "create the nerd tree window
     let splitLocation = g:NERDTreeWinPos ==# "left" ? "topleft " : "botright "
     let splitSize = g:NERDTreeWinSize
-    silent! exec splitLocation . 'vertical ' . splitSize . ' new'
 
     if !exists('t:NERDTreeBufName')
         let t:NERDTreeBufName = s:nextBufferName()
+        silent! exec splitLocation . 'vertical ' . splitSize . ' new'
         silent! exec "edit " . t:NERDTreeBufName
     else
+        silent! exec splitLocation . 'vertical ' . splitSize . ' split'
         silent! exec "buffer " . t:NERDTreeBufName
     endif
 
@@ -2404,6 +2405,7 @@ function! s:dumpHelp()
         let @h=@h."\" ============================\n"
         let @h=@h."\" File node mappings~\n"
         let @h=@h."\" ". (g:NERDTreeMouseMode ==# 3 ? "single" : "double") ."-click,\n"
+        let @h=@h."\" <CR>,\n"
         if b:NERDTreeType ==# "primary"
             let @h=@h."\" ". g:NERDTreeMapActivateNode .": open in prev window\n"
         else
@@ -2516,14 +2518,15 @@ function! s:echoError(msg)
     call s:echo(a:msg)
     echohl normal
 endfunction
-"FUNCTION: s:firstNormalWindow(){{{2
+"FUNCTION: s:firstUsableWindow(){{{2
 "find the window number of the first normal window
-function! s:firstNormalWindow()
+function! s:firstUsableWindow()
     let i = 1
     while i <= winnr("$")
         let bnum = winbufnr(i)
         if bnum != -1 && getbufvar(bnum, '&buftype') ==# ''
                     \ && !getwinvar(i, '&previewwindow')
+                    \ && (!getbufvar(bnum, '&modified') || &hidden)
             return i
         endif
 
@@ -2630,8 +2633,8 @@ function! s:isTreeOpen()
     return s:getTreeWinNum() != -1
 endfunction
 "FUNCTION: s:isWindowUsable(winnumber) {{{2
-"Returns 1 if opening a file from the tree in the given window requires it to
-"be split
+"Returns 0 if opening a file from the tree in the given window requires it to
+"be split, 1 otherwise
 "
 "Args:
 "winnumber: the number of the window in question
@@ -3042,7 +3045,8 @@ function! s:activateNode(forceKeepWindowOpen)
                 call bookmark.toRoot()
             else
                 if bookmark.validate()
-                    call (s:TreeFileNode.New(bookmark.path)).open()
+                    let n = s:TreeFileNode.New(bookmark.path)
+                    call n.open()
                 endif
             endif
         endif
@@ -3058,6 +3062,7 @@ function! s:bindMappings()
 
     exec "nnoremap <silent> <buffer> ". g:NERDTreeMapActivateNode . " :call <SID>activateNode(0)<cr>"
     exec "nnoremap <silent> <buffer> ". g:NERDTreeMapOpenSplit ." :call <SID>openEntrySplit(0,0)<cr>"
+    exec "nnoremap <silent> <buffer> <cr> :call <SID>activateNode(0)<cr>"
 
     exec "nnoremap <silent> <buffer> ". g:NERDTreeMapPreview ." :call <SID>previewNode(0)<cr>"
     exec "nnoremap <silent> <buffer> ". g:NERDTreeMapPreviewSplit ." :call <SID>previewNode(1)<cr>"