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

@@ -202,13 +202,16 @@ go......Open selected file, but leave cursor in the NERDTree.....|NERDTree-go|
 t.......Open selected node/bookmark in a new tab.................|NERDTree-t|
 T.......Same as 't' but keep the focus on the current tab........|NERDTree-T|
 i.......Open selected file in a split window.....................|NERDTree-i|
-gi......Same as i, but leave the cursor on the NERDTree..........|NERDTree-i|
+gi......Same as i, but leave the cursor on the NERDTree..........|NERDTree-gi|
+s.......Open selected file in a new vsplit.......................|NERDTree-s|
+gs......Same as s, but leave the cursor on the NERDTree..........|NERDTree-gs|
 !.......Execute the current file.................................|NERDTree-!|
 O.......Recursively open the selected directory..................|NERDTree-O|
 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.
@@ -219,8 +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-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-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|
@@ -308,6 +311,26 @@ The same as |NERDTree-i| except that the cursor is not moved.
 The key combo for this mapping is always "g" + NERDTreeMapOpenSplit (see
 |NERDTree-i|).
 
+------------------------------------------------------------------------------
+                                                                  *NERDTree-s*
+Default key: s
+Map option: NERDTreeMapOpenVSplit
+Applies to: files.
+
+Opens the selected file in a new vertically split window and puts the cursor in
+the new window.
+
+------------------------------------------------------------------------------
+                                                                 *NERDTree-gs*
+Default key: gs
+Map option: None
+Applies to: files.
+
+The same as |NERDTree-s| except that the cursor is not moved.
+
+The key combo for this mapping is always "g" + NERDTreeMapOpenVSplit (see
+|NERDTree-s|).
+
 ------------------------------------------------------------------------------
                                                                   *NERDTree-!*
 Default key: !
@@ -408,16 +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*
+                                                                *NERDTree-C-J*
-Default key: <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*
+                                                                *NERDTree-C-K*
-Default key: <C-k>
+Default key: <C-K>
 Map option: NERDTreeMapJumpPrevSibling
 Applies to: files and directories.
 
@@ -475,6 +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
@@ -619,6 +650,8 @@ NERD tree. These options should be set in your vimrc.
 |'NERDTreeSortOrder'|           Tell the NERD tree how to sort the nodes in
                                 the tree.
 
+|'NERDTreeStatusline'|          Set a statusline for NERD tree windows.
+
 |'NERDTreeWinPos'|              Tells the script where to put the NERD tree
                                 window.
 
@@ -655,7 +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.
@@ -718,7 +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'*
@@ -871,6 +904,20 @@ Other examples: >
 3. Dirs will appear first, then ruby and php. Swap files, bak files and vim
    backup files will appear last with everything else preceding them.
 
+------------------------------------------------------------------------------
+                                                        *'NERDTreeStatusline'*
+Values: Any valid statusline setting.
+Default: %{b:NERDTreeRoot.path.strForOS(0)}
+
+Tells the script what to use as the |'statusline'| setting for NERD tree
+windows.
+
+Note that the statusline is set using |:let-&| not |:set| so escaping spaces
+isn't necessary.
+
+Setting this option to -1 will will deactivate it so that your global
+statusline setting is used instead.
+
 ------------------------------------------------------------------------------
                                                             *'NERDTreeWinPos'*
 Values: "left" or "right"
@@ -879,9 +926,9 @@ Default: "left".
 This option is used to determine where NERD tree window is placed on the
 screen.
 
-This option is makes it possible to use two different explorer type
+This option makes it possible to use two different explorer plugins
-plugins simultaneously. For example, you could have the taglist plugin on the
+simultaneously. For example, you could have the taglist plugin on the left of
-left of the window and the NERD tree on the right.
+the window and the NERD tree on the right.
 
 ------------------------------------------------------------------------------
                                                            *'NERDTreeWinSize'*
@@ -950,6 +997,33 @@ 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
+      NERDTree-gs
+    - make the statusline for the nerd tree window default to something
+      hopefully more useful. See :help 'NERDTreeStatusline'
+    Bugfixes:
+    - make the hijack netrw functionality work when vim is started with "vim
+      <some dir>" (thanks to Alf Mikula for the patch).
+    - fix a bug where the CWD wasnt being changed for some operations even when
+      NERDTreeChDirMode==2 (thanks to Lucas S. Buchala)
+    - add -bar to all the nerd tree :commands so they can chain with other
+      :commands (thanks to tpope)
+    - fix bugs when ignorecase was set (thanks to nach)
+    - fix a bug with the relative path code (thanks to nach)
+    - fix a bug where doing a :cd would cause :NERDTreeToggle to fail (thanks nach)
+
+
 3.0.1
     Bugfixes:
     - fix bugs with :NERDTreeToggle and :NERDTreeMirror when 'hidden
@@ -1010,6 +1084,9 @@ just downloaded pr0n instead.
     Tim Pope (tpope)
     James Kanze
     James Vega (jamessan)
+    Frederic Chanal (nach)
+    Alf Mikula
+    Lucas S. Buchala
 
 ==============================================================================
 8. License                                                   *NERDTreeLicense*

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: 12 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 = '3.0.1'
+let s:NERD_tree_version = '3.1.1'
 
 " SECTION: Script init stuff {{{1
 "============================================================
@@ -79,6 +79,7 @@ endif
 "once here
 let s:NERDTreeSortStarIndex = index(g:NERDTreeSortOrder, '*')
 
+call s:initVariable("g:NERDTreeStatusline", "%{b:NERDTreeRoot.path.strForOS(0)}")
 call s:initVariable("g:NERDTreeWinPos", "left")
 call s:initVariable("g:NERDTreeWinSize", 31)
 
@@ -116,8 +117,10 @@ call s:initVariable("g:NERDTreeMapOpenInTab", "t")
 call s:initVariable("g:NERDTreeMapOpenInTabSilent", "T")
 call s:initVariable("g:NERDTreeMapOpenRecursively", "O")
 call s:initVariable("g:NERDTreeMapOpenSplit", "i")
+call s:initVariable("g:NERDTreeMapOpenVSplit", "s")
 call s:initVariable("g:NERDTreeMapPreview", "g" . NERDTreeMapActivateNode)
 call s:initVariable("g:NERDTreeMapPreviewSplit", "g" . NERDTreeMapOpenSplit)
+call s:initVariable("g:NERDTreeMapPreviewVSplit", "g" . NERDTreeMapOpenVSplit)
 call s:initVariable("g:NERDTreeMapQuit", "q")
 call s:initVariable("g:NERDTreeMapRefresh", "r")
 call s:initVariable("g:NERDTreeMapRefreshRoot", "R")
@@ -147,11 +150,11 @@ let s:next_buffer_number = 1
 " SECTION: Commands {{{1
 "============================================================
 "init the command that users start the nerd tree with
-command! -n=? -complete=dir NERDTree :call s:initNerdTree('<args>')
+command! -n=? -complete=dir -bar NERDTree :call s:initNerdTree('<args>')
-command! -n=? -complete=dir NERDTreeToggle :call s:toggle('<args>')
+command! -n=? -complete=dir -bar NERDTreeToggle :call s:toggle('<args>')
-command! -n=0 NERDTreeClose :call s:closeTreeIfOpen()
+command! -n=0 -bar NERDTreeClose :call s:closeTreeIfOpen()
-command! -n=1 -complete=customlist,s:completeBookmarks NERDTreeFromBookmark call s:initNerdTree('<args>')
+command! -n=1 -complete=customlist,s:completeBookmarks -bar NERDTreeFromBookmark call s:initNerdTree('<args>')
-command! -n=0 -complete=customlist,s:completeNERDTreeMirrors NERDTreeMirror call s:initNerdTreeMirror()
+command! -n=0 -bar NERDTreeMirror call s:initNerdTreeMirror()
 " SECTION: Auto commands {{{1
 "============================================================
 augroup NERDTree
@@ -164,7 +167,7 @@ augroup END
 if g:NERDTreeHijackNetrw
     augroup NERDTreeHijackNetrw
         autocmd VimEnter * silent! autocmd! FileExplorer
-        au BufEnter * call s:checkForBrowse(expand("<amatch>"))
+        au BufEnter,VimEnter * call s:checkForBrowse(expand("<amatch>"))
     augroup END
 endif
 
@@ -178,7 +181,7 @@ let s:Bookmark = {}
 " with the same name, just update the path for that bookmark
 function! s:Bookmark.AddBookmark(name, path)
     for i in s:Bookmark.Bookmarks()
-        if i.name == a:name
+        if i.name ==# a:name
             let i.path = a:path
             return
         endif
@@ -211,7 +214,7 @@ endfunction
 " bookmark is found
 function! s:Bookmark.BookmarkFor(name)
     for i in s:Bookmark.Bookmarks()
-        if i.name == a:name
+        if i.name ==# a:name
             return i
         endif
     endfor
@@ -489,7 +492,7 @@ endfunction
 "FUNCTION: TreeFileNode.renderToString {{{3
 "returns a string representation for this tree to be rendered in the view
 function! s:TreeFileNode.renderToString()
-    return self._renderToString(0, 0, [], self.getChildCount() == 1)
+    return self._renderToString(0, 0, [], self.getChildCount() ==# 1)
 endfunction
 
 
@@ -502,14 +505,14 @@ endfunction
 "isLastChild:true if this curNode is the last child of its parent
 function! s:TreeFileNode._renderToString(depth, drawText, vertMap, isLastChild)
     let output = ""
-    if a:drawText == 1
+    if a:drawText ==# 1
 
         let treeParts = ''
 
         "get all the leading spaces and vertical tree parts for this line
         if a:depth > 1
             for j in a:vertMap[0:-2]
-                if j == 1
+                if j ==# 1
                     let treeParts = treeParts . '| '
                 else
                     let treeParts = treeParts . '  '
@@ -543,7 +546,7 @@ function! s:TreeFileNode._renderToString(depth, drawText, vertMap, isLastChild)
     endif
 
     "if the node is an open dir, draw its children
-    if self.path.isDirectory == 1 && self.isOpen == 1
+    if self.path.isDirectory ==# 1 && self.isOpen ==# 1
 
         let childNodesToDraw = self.getVisibleChildren()
         if len(childNodesToDraw) > 0
@@ -574,7 +577,7 @@ endfunction
 "Args:
 "treenode: the other treenode to compare to
 function! s:TreeFileNode.equals(treenode)
-    return self.path.str(1) == a:treenode.path.str(1)
+    return self.path.str(1) ==# a:treenode.path.str(1)
 endfunction
 
 "FUNCTION: TreeFileNode.findNode(path) {{{3
@@ -632,7 +635,7 @@ function! s:TreeFileNode.findSibling(direction)
 
         if siblingIndx != -1
             "move a long to the next potential sibling node
-            let siblingIndx = a:direction == 1 ? siblingIndx+1 : siblingIndx-1
+            let siblingIndx = a:direction ==# 1 ? siblingIndx+1 : siblingIndx-1
 
             "keep moving along to the next sibling till we find one that is valid
             let numSiblings = self.parent.getChildCount()
@@ -640,12 +643,12 @@ function! s:TreeFileNode.findSibling(direction)
 
                 "if the next node is not an ignored node (i.e. wont show up in the
                 "view) then return it
-                if self.parent.children[siblingIndx].path.ignore() == 0
+                if self.parent.children[siblingIndx].path.ignore() ==# 0
                     return self.parent.children[siblingIndx]
                 endif
 
                 "go to next node
-                let siblingIndx = a:direction == 1 ? siblingIndx+1 : siblingIndx-1
+                let siblingIndx = a:direction ==# 1 ? siblingIndx+1 : siblingIndx-1
             endwhile
         endif
     endif
@@ -675,24 +678,24 @@ function! s:TreeFileNode.getLineNum()
     while lnum > 0
         let lnum = lnum + 1
         "have we reached the bottom of the tree?
-        if lnum == totalLines+1
+        if lnum ==# totalLines+1
             return -1
         endif
 
         let curLine = getline(lnum)
 
         let indent = s:indentLevelFor(curLine)
-        if indent == curPathComponent
+        if indent ==# curPathComponent
             let curLine = s:stripMarkupFromLine(curLine, 1)
 
             let curPath =  join(pathcomponents, '/') . '/' . curLine
-            if stridx(fullpath, curPath, 0) == 0
+            if stridx(fullpath, curPath, 0) ==# 0
-                if fullpath == curPath || strpart(fullpath, len(curPath)-1,1) == '/'
+                if fullpath ==# curPath || strpart(fullpath, len(curPath)-1,1) ==# '/'
                     let curLine = substitute(curLine, '/ *$', '', '')
                     call add(pathcomponents, curLine)
                     let curPathComponent = curPathComponent + 1
 
-                    if fullpath == curPath
+                    if fullpath ==# curPath
                         return lnum
                     endif
                 endif
@@ -717,7 +720,7 @@ endfunction
 function! s:TreeFileNode.GetSelected()
     try
         let path = s:getPath(line("."))
-        if path == {}
+        if path ==# {}
             return {}
         endif
         return b:NERDTreeRoot.findNode(path)
@@ -754,7 +757,7 @@ function! s:TreeFileNode.makeRoot()
     call b:NERDTreeRoot.open()
 
     "change dir to the dir of the new root if instructed to
-    if g:NERDTreeChDirMode == 2
+    if g:NERDTreeChDirMode ==# 2
         exec "cd " . b:NERDTreeRoot.path.strForEditCmd()
     endif
 endfunction
@@ -782,25 +785,23 @@ endfunction
 "ARGS:
 "treenode: file node to open
 function! s:TreeFileNode.open()
-    if b:NERDTreeType == "secondary"
+    if b:NERDTreeType ==# "secondary"
         exec 'edit ' . self.path.strForEditCmd()
         return
     endif
 
-    call s:putCursorInTreeWin()
-
     "if the file is already open in this tab then just stick the cursor in it
     let winnr = bufwinnr('^' . self.path.strForOS(0) . '$')
     if winnr != -1
         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
@@ -818,7 +819,7 @@ endfunction
 "Open this node in a new window
 function! s:TreeFileNode.openSplit()
 
-    if b:NERDTreeType == "secondary"
+    if b:NERDTreeType ==# "secondary"
         exec "split " . self.path.strForEditCmd()
         return
     endif
@@ -836,15 +837,15 @@ function! s:TreeFileNode.openSplit()
     " 'right' and 'below' will be set to the settings needed for
     " splitbelow and splitright IF the explorer is the only window.
     "
-    let there= g:NERDTreeWinPos == "left" ? "wincmd h" : "wincmd l"
+    let there= g:NERDTreeWinPos ==# "left" ? "wincmd h" : "wincmd l"
-    let back = g:NERDTreeWinPos == "left" ? "wincmd l" : "wincmd h"
+    let back = g:NERDTreeWinPos ==# "left" ? "wincmd l" : "wincmd h"
-    let right= g:NERDTreeWinPos == "left"
+    let right= g:NERDTreeWinPos ==# "left"
     let below=0
 
     " Attempt to go to adjacent window
     call s:exec(back)
 
-    let onlyOneWin = (winnr() == s:getTreeWinNum())
+    let onlyOneWin = (winnr("$") ==# 1)
 
     " If no adjacent window, set splitright and splitbelow appropriately
     if onlyOneWin
@@ -880,7 +881,27 @@ function! s:TreeFileNode.openSplit()
     let &splitbelow=savesplitbelow
     let &splitright=savesplitright
 endfunction
+"FUNCTION: TreeFileNode.openVSplit() {{{3
+"Open this node in a new vertical window
+function! s:TreeFileNode.openVSplit()
+    if b:NERDTreeType ==# "secondary"
+        exec "vnew " . self.path.strForEditCmd()
+        return
+    endif
 
+    let winwidth = winwidth(".")
+    if winnr("$")==#1
+        let winwidth = g:NERDTreeWinSize
+    endif
+
+    call s:exec("wincmd p")
+    exec "vnew " . self.path.strForEditCmd()
+
+    "resize the nerd tree back to the original size
+    call s:putCursorInTreeWin()
+    exec("silent vertical resize ". winwidth)
+    call s:exec('wincmd p')
+endfunction
 "FUNCTION: TreeFileNode.putCursorHere(isJump, recurseUpward){{{3
 "Places the cursor on the line number this node is rendered on
 "
@@ -898,7 +919,7 @@ function! s:TreeFileNode.putCursorHere(isJump, recurseUpward)
     else
         if a:recurseUpward
             let node = self
-            while node != {} && node.getLineNum() == -1
+            while node != {} && node.getLineNum() ==# -1
                 let node = node.parent
                 call node.open()
             endwhile
@@ -1011,7 +1032,7 @@ function! s:TreeDirNode.findNode(path)
     if a:path.equals(self.path)
         return self
     endif
-    if stridx(a:path.str(1), self.path.str(1), 0) == -1
+    if stridx(a:path.str(1), self.path.str(1), 0) ==# -1
         return {}
     endif
 
@@ -1040,12 +1061,12 @@ endfunction
 "Args:
 "path: a path object
 function! s:TreeDirNode.getChild(path)
-    if stridx(a:path.str(1), self.path.str(1), 0) == -1
+    if stridx(a:path.str(1), self.path.str(1), 0) ==# -1
         return {}
     endif
 
     let index = self.getChildIndex(a:path)
-    if index == -1
+    if index ==# -1
         return {}
     else
         return self.children[index]
@@ -1076,7 +1097,7 @@ endfunction
 "Args:
 "path: a path object
 function! s:TreeDirNode.getChildIndex(path)
-    if stridx(a:path.str(1), self.path.str(1), 0) == -1
+    if stridx(a:path.str(1), self.path.str(1), 0) ==# -1
         return -1
     endif
 
@@ -1087,9 +1108,9 @@ function! s:TreeDirNode.getChildIndex(path)
         let mid = (a+z)/2
         let diff = a:path.compareTo(self.children[mid].path)
 
-        if diff == -1
+        if diff ==# -1
             let z = mid
-        elseif diff == 1
+        elseif diff ==# 1
             let a = mid+1
         else
             return mid
@@ -1105,7 +1126,7 @@ unlet s:TreeDirNode.GetSelected
 function! s:TreeDirNode.GetSelected()
     let currentDir = s:TreeFileNode.GetSelected()
     if currentDir != {} && !currentDir.isRoot()
-        if currentDir.path.isDirectory == 0
+        if currentDir.path.isDirectory ==# 0
             let currentDir = currentDir.parent
         endif
     endif
@@ -1125,7 +1146,7 @@ endfunction
 function! s:TreeDirNode.getVisibleChildren()
     let toReturn = []
     for i in self.children
-        if i.path.ignore() == 0
+        if i.path.ignore() ==# 0
             call add(toReturn, i)
         endif
     endfor
@@ -1216,7 +1237,7 @@ endfunction
 unlet s:TreeDirNode.open
 function! s:TreeDirNode.open()
     let self.isOpen = 1
-    if self.children == []
+    if self.children ==# []
         return self._initChildren(0)
     else
         return 0
@@ -1229,7 +1250,7 @@ endfunction
 function! s:TreeDirNode.openExplorer()
     let oldwin = winnr()
     call s:exec('wincmd p')
-    if oldwin == winnr() || (&modified && s:bufInWindows(winbufnr(winnr())) < 2)
+    if oldwin ==# winnr() || (&modified && s:bufInWindows(winbufnr(winnr())) < 2)
         call s:exec('wincmd p')
         call self.openSplit()
     else
@@ -1254,14 +1275,14 @@ endfunction
 "Args:
 "forceOpen: 1 if this node should be opened regardless of file filters
 function! s:TreeDirNode._openRecursively2(forceOpen)
-    if self.path.ignore() == 0 || a:forceOpen
+    if self.path.ignore() ==# 0 || a:forceOpen
         let self.isOpen = 1
-        if self.children == []
+        if self.children ==# []
             call self._initChildren(1)
         endif
 
         for i in self.children
-            if i.path.isDirectory == 1
+            if i.path.isDirectory ==# 1
                 call i._openRecursively2(0)
             endif
         endfor
@@ -1348,7 +1369,7 @@ endfunction
 "FUNCTION: TreeDirNode.toggleOpen() {{{3
 "Opens this directory if it is closed and vice versa
 function! s:TreeDirNode.toggleOpen()
-    if self.isOpen == 1
+    if self.isOpen ==# 1
         call self.close()
     else
         call self.open()
@@ -1427,7 +1448,7 @@ endfunction
 "FUNCTION: Path.changeToDir() {{{3
 function! s:Path.changeToDir()
     let dir = self.strForCd()
-    if self.isDirectory == 0
+    if self.isDirectory ==# 0
         let dir = self.getPathTrunk().strForCd()
     endif
 
@@ -1454,7 +1475,7 @@ function! s:Path.compareTo(path)
     let thatPath = a:path.getLastPathComponent(1)
 
     "if the paths are the same then clearly we return 0
-    if thisPath == thatPath
+    if thisPath ==# thatPath
         return 0
     endif
 
@@ -1689,11 +1710,11 @@ function! s:Path.ignore()
     endif
 
     "dont show hidden files unless instructed to
-    if b:NERDTreeShowHidden == 0 && lastPathComponent =~ '^\.'
+    if b:NERDTreeShowHidden ==# 0 && lastPathComponent =~ '^\.'
         return 1
     endif
 
-    if b:NERDTreeShowFiles == 0 && self.isDirectory == 0
+    if b:NERDTreeShowFiles ==# 0 && self.isDirectory ==# 0
         return 1
     endif
 
@@ -1717,7 +1738,7 @@ endfunction
 "Args:
 "path: the other path obj to compare this with
 function! s:Path.equals(path)
-    return self.str(0) == a:path.str(0)
+    return self.str(0) ==# a:path.str(0)
 endfunction
 
 "FUNCTION: Path.New() {{{3
@@ -1741,7 +1762,7 @@ function! s:Path.readInfoFromDisk(fullpath)
 
     let fullpath = s:Path.WinToUnixPath(a:fullpath)
 
-    if getftype(fullpath) == "fifo"
+    if getftype(fullpath) ==# "fifo"
         throw "NERDTree.InvalidFiletypeError: Cant handle FIFO files: " . a:fullpath
     endif
 
@@ -1752,7 +1773,7 @@ function! s:Path.readInfoFromDisk(fullpath)
         let self.isDirectory = 1
     elseif filereadable(a:fullpath)
         let self.isDirectory = 0
-        let self.isReadOnly = filewritable(a:fullpath) == 0
+        let self.isReadOnly = filewritable(a:fullpath) ==# 0
     else
         throw "NERDTree.InvalidArgumentsError: Invalid path = " . a:fullpath
     endif
@@ -1796,7 +1817,7 @@ endfunction
 "
 "Renames this node on the filesystem
 function! s:Path.rename(newPath)
-    if a:newPath == ''
+    if a:newPath ==# ''
         throw "NERDTree.InvalidArgumentsError: Invalid newPath for renaming = ". a:newPath
     endif
 
@@ -1862,7 +1883,7 @@ endfunction
 "Return:
 "a string that can be used in the view to represent this path
 function! s:Path.strDisplay()
-    if self.cachedDisplayString == ""
+    if self.cachedDisplayString ==# ""
         call self.cacheDisplayString()
     endif
 
@@ -1882,12 +1903,14 @@ function! s:Path.strForEditCmd()
         let cwd = tolower(getcwd())
     endif
 
+    let cwd = cwd . s:os_slash
+
     "return a relative path if we can
-    if stridx(p, cwd) == 0
+    if stridx(p, cwd) ==# 0
-        let p = strpart(p, strlen(cwd)+1)
+        let p = strpart(p, strlen(cwd))
     endif
 
-    if p == ''
+    if p ==# ''
         let p = '.'
     endif
 
@@ -1985,7 +2008,7 @@ function! s:bufInWindows(bnum)
         if bufnum < 0
             break
         endif
-        if bufnum == a:bnum
+        if bufnum ==# a:bnum
             let cnt = cnt + 1
         endif
         let winnum = winnum + 1
@@ -2030,7 +2053,7 @@ function! s:initNerdTree(name)
     if s:Bookmark.BookmarkExistsFor(a:name)
         let path = s:Bookmark.BookmarkFor(a:name).path
     else
-        let dir = a:name == '' ? getcwd() : a:name
+        let dir = a:name ==# '' ? getcwd() : a:name
 
         "hack to get an absolute path if a relative path is given
         if dir =~ '^\.'
@@ -2122,6 +2145,8 @@ function! s:initNerdTreeInPlace(dir)
         setlocal cursorline
     endif
 
+    call s:setupStatusline()
+
     let b:treeShowHelp = 0
     let b:NERDTreeIgnoreEnabled = 1
     let b:NERDTreeShowFiles = g:NERDTreeShowFiles
@@ -2169,12 +2194,12 @@ function! s:initNerdTreeMirror()
         let choices = ["Choose a tree to mirror"]
         let choices = extend(choices, sort(keys(options)))
         let choice = inputlist(choices)
-        if choice < 1 || choice > len(options) || choice == ''
+        if choice < 1 || choice > len(options) || choice ==# ''
             return
         endif
 
         let bufferName = options[keys(options)[choice-1]]
-    elseif len(keys(options)) == 1
+    elseif len(keys(options)) ==# 1
         let bufferName = values(options)[0]
     else
         call s:echo("No trees to mirror")
@@ -2231,7 +2256,7 @@ endfunction
 function! s:unique(list)
   let uniqlist = []
   for elem in a:list
-    if index(uniqlist, elem) == -1
+    if index(uniqlist, elem) ==# -1
       let uniqlist += [elem]
     endif
   endfor
@@ -2328,20 +2353,23 @@ endfunction
 "options etc
 function! s:createTreeWin()
     "create the nerd tree window
-    let splitLocation = g:NERDTreeWinPos == "left" ? "topleft " : "botright "
+    let splitLocation = g:NERDTreeWinPos ==# "left" ? "topleft " : "botright "
     let splitSize = g:NERDTreeWinSize
+
     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
-    let cmd = splitLocation . 'vertical ' . splitSize . ' new ' . t:NERDTreeBufName
-    silent! execute cmd
 
     setlocal winfixwidth
 
     "throwaway buffer options
     setlocal noswapfile
     setlocal buftype=nofile
-    "setlocal bufhidden=delete
     setlocal nowrap
     setlocal foldcolumn=0
     setlocal nobuflisted
@@ -2358,7 +2386,7 @@ function! s:createTreeWin()
         setlocal cursorline
     endif
 
-
+    call s:setupStatusline()
 
     call s:bindMappings()
     setfiletype nerdtree
@@ -2372,17 +2400,18 @@ endfunction
 "prints out the quick help
 function! s:dumpHelp()
     let old_h = @h
-    if b:treeShowHelp == 1
+    if b:treeShowHelp ==# 1
         let @h=   "\" NERD tree (" . s:NERD_tree_version . ") quickhelp~\n"
         let @h=@h."\" ============================\n"
         let @h=@h."\" File node mappings~\n"
-        let @h=@h."\" ". (g:NERDTreeMouseMode == 3 ? "single" : "double") ."-click,\n"
+        let @h=@h."\" ". (g:NERDTreeMouseMode ==# 3 ? "single" : "double") ."-click,\n"
-        if b:NERDTreeType == "primary"
+        let @h=@h."\" <CR>,\n"
+        if b:NERDTreeType ==# "primary"
             let @h=@h."\" ". g:NERDTreeMapActivateNode .": open in prev window\n"
         else
             let @h=@h."\" ". g:NERDTreeMapActivateNode .": open in current window\n"
         endif
-        if b:NERDTreeType == "primary"
+        if b:NERDTreeType ==# "primary"
             let @h=@h."\" ". g:NERDTreeMapPreview .": preview\n"
         endif
         let @h=@h."\" ". g:NERDTreeMapOpenInTab.": open in new tab\n"
@@ -2390,11 +2419,13 @@ function! s:dumpHelp()
         let @h=@h."\" middle-click,\n"
         let @h=@h."\" ". g:NERDTreeMapOpenSplit .": open split\n"
         let @h=@h."\" ". g:NERDTreeMapPreviewSplit .": preview split\n"
+        let @h=@h."\" ". g:NERDTreeMapOpenVSplit .": open vsplit\n"
+        let @h=@h."\" ". g:NERDTreeMapPreviewVSplit .": preview vsplit\n"
         let @h=@h."\" ". g:NERDTreeMapExecute.": Execute file\n"
 
         let @h=@h."\"\n\" ----------------------------\n"
         let @h=@h."\" Directory node mappings~\n"
-        let @h=@h."\" ". (g:NERDTreeMouseMode == 1 ? "double" : "single") ."-click,\n"
+        let @h=@h."\" ". (g:NERDTreeMouseMode ==# 1 ? "double" : "single") ."-click,\n"
         let @h=@h."\" ". g:NERDTreeMapActivateNode .": open & close node\n"
         let @h=@h."\" ". g:NERDTreeMapOpenRecursively .": recursively open node\n"
         let @h=@h."\" ". g:NERDTreeMapCloseDir .": close parent of node\n"
@@ -2487,14 +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') == ''
+        if bnum != -1 && getbufvar(bnum, '&buftype') ==# ''
                     \ && !getwinvar(i, '&previewwindow')
+                    \ && (!getbufvar(bnum, '&modified') || &hidden)
             return i
         endif
 
@@ -2525,7 +2557,7 @@ function! s:getPath(ln)
         return {}
     endif
 
-    if line == s:tree_up_dir_line
+    if line ==# s:tree_up_dir_line
         return b:NERDTreeRoot.path.getParent()
     endif
 
@@ -2601,14 +2633,14 @@ 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
+"Returns 0 if opening a file from the tree in the given window requires it to
-"be split
+"be split, 1 otherwise
 "
 "Args:
 "winnumber: the number of the window in question
 function! s:isWindowUsable(winnumber)
     "gotta split if theres only one window (i.e. the NERD tree)
-    if winnr("$") == 1
+    if winnr("$") ==# 1
         return 0
     endif
 
@@ -2636,7 +2668,7 @@ endfunction
 " direction: 0 if going to first child, 1 if going to last
 function! s:jumpToChild(direction)
     let currentNode = s:TreeFileNode.GetSelected()
-    if currentNode == {} || currentNode.isRoot()
+    if currentNode ==# {} || currentNode.isRoot()
         call s:echo("cannot jump to " . (a:direction ? "last" : "first") .  " child")
         return
     end
@@ -2672,7 +2704,7 @@ endfunction
 "     del the buffer
 function! s:promptToDelBuffer(bufnum, msg)
     echo a:msg
-    if nr2char(getchar()) == 'y'
+    if nr2char(getchar()) ==# 'y'
         exec "silent bdelete! " . a:bufnum
     endif
 endfunction
@@ -2825,6 +2857,12 @@ function! s:saveScreenState()
     endtry
 endfunction
 
+"FUNCTION: s:setupStatusline() {{{2
+function! s:setupStatusline()
+    if g:NERDTreeStatusline != -1
+        let &l:statusline = g:NERDTreeStatusline
+    endif
+endfunction
 "FUNCTION: s:setupSyntaxHighlighting() {{{2
 function! s:setupSyntaxHighlighting()
     "treeFlags are syntax items that should be invisible, but give clues as to
@@ -2942,7 +2980,7 @@ function! s:stripMarkupFromLine(line, removeLeadingSpaces)
         let wasdir = 1
     endif
     let line = substitute (line,' -> .*',"","") " remove link to
-    if wasdir == 1
+    if wasdir ==# 1
         let line = substitute (line, '/\?$', '/', "")
     endif
 
@@ -2984,7 +3022,7 @@ endfunction
 "args:
 "forceKeepWindowOpen - dont close the window even if NERDTreeQuitOnOpen is set
 function! s:activateNode(forceKeepWindowOpen)
-    if getline(".") == s:tree_up_dir_line
+    if getline(".") ==# s:tree_up_dir_line
         return s:upDir(0)
     endif
 
@@ -3007,7 +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
@@ -3022,11 +3061,14 @@ function! s:bindMappings()
     nnoremap <silent> <buffer> <2-leftmouse> :call <SID>activateNode(0)<cr>
 
     exec "nnoremap <silent> <buffer> ". g:NERDTreeMapActivateNode . " :call <SID>activateNode(0)<cr>"
-    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapOpenSplit ." :call <SID>openEntrySplit(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>"
 
+    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapOpenVSplit ." :call <SID>openEntrySplit(1,0)<cr>"
+    exec "nnoremap <silent> <buffer> ". g:NERDTreeMapPreviewVSplit ." :call <SID>previewNode(2)<cr>"
 
     exec "nnoremap <silent> <buffer> ". g:NERDTreeMapExecute ." :call <SID>executeNode()<cr>"
 
@@ -3112,7 +3154,7 @@ function! s:checkForActivate()
             endif
         endif
 
-        if (g:NERDTreeMouseMode == 2 && currentNode.path.isDirectory) || g:NERDTreeMouseMode == 3
+        if (g:NERDTreeMouseMode ==# 2 && currentNode.path.isDirectory) || g:NERDTreeMouseMode ==# 3
             if char !~ s:tree_markup_reg && startToCur !~ '\/$'
                 call s:activateNode(0)
                 return
@@ -3124,7 +3166,7 @@ endfunction
 " FUNCTION: s:chCwd() {{{2
 function! s:chCwd()
     let treenode = s:TreeFileNode.GetSelected()
-    if treenode == {}
+    if treenode ==# {}
         call s:echo("Select a node first")
         return
     endif
@@ -3140,7 +3182,7 @@ endfunction
 " changes the current root to the selected one
 function! s:chRoot()
     let treenode = s:TreeFileNode.GetSelected()
-    if treenode == {}
+    if treenode ==# {}
         call s:echo("Select a node first")
         return
     endif
@@ -3152,7 +3194,7 @@ endfunction
 
 " FUNCTION: s:clearBookmarks(bookmarks) {{{2
 function! s:clearBookmarks(bookmarks)
-    if a:bookmarks == ''
+    if a:bookmarks ==# ''
         let currentNode = s:TreeFileNode.GetSelected()
         if currentNode != {}
             call currentNode.clearBoomarks()
@@ -3169,7 +3211,7 @@ endfunction
 " closes all childnodes of the current node
 function! s:closeChildren()
     let currentNode = s:TreeDirNode.GetSelected()
-    if currentNode == {}
+    if currentNode ==# {}
         call s:echo("Select a node first")
         return
     endif
@@ -3182,7 +3224,7 @@ endfunction
 " closes the parent dir of the current node
 function! s:closeCurrentDir()
     let treenode = s:TreeFileNode.GetSelected()
-    if treenode == {}
+    if treenode ==# {}
         call s:echo("Select a node first")
         return
     endif
@@ -3199,7 +3241,7 @@ endfunction
 " FUNCTION: s:closeTreeWindow() {{{2
 " close the tree window
 function! s:closeTreeWindow()
-    if b:NERDTreeType == "secondary" && b:NERDTreePreviousBuf != -1
+    if b:NERDTreeType ==# "secondary" && b:NERDTreePreviousBuf != -1
         exec "buffer " . b:NERDTreePreviousBuf
     else
         if winnr("$") > 1
@@ -3212,7 +3254,7 @@ endfunction
 " FUNCTION: s:copyNode() {{{2
 function! s:copyNode()
     let currentNode = s:TreeFileNode.GetSelected()
-    if currentNode == {}
+    if currentNode ==# {}
         call s:echo("Put the cursor on a file node first")
         return
     endif
@@ -3230,7 +3272,7 @@ function! s:copyNode()
         if currentNode.path.copyingWillOverwrite(newNodePath)
             call s:echo("\nWarning: copying may overwrite files! Continue? (yN)")
             let choice = nr2char(getchar())
-            let confirmed = choice == 'y'
+            let confirmed = choice ==# 'y'
         endif
 
         if confirmed
@@ -3252,14 +3294,14 @@ endfunction
 " if the cursor is on a bookmark, prompt to delete
 function! s:deleteBookmark()
     let bookmark = s:getSelectedBookmark()
-    if bookmark == {}
+    if bookmark ==# {}
         call s:echo("Put the cursor on a bookmark")
         return
     endif
 
     echo  "Are you sure you wish to delete the bookmark:\n\"" . bookmark.name . "\" (yN):"
 
-    if  nr2char(getchar()) == 'y'
+    if  nr2char(getchar()) ==# 'y'
         try
             call bookmark.delete()
             call s:renderView()
@@ -3278,7 +3320,7 @@ endfunction
 " to delete it
 function! s:deleteNode()
     let currentNode = s:TreeFileNode.GetSelected()
-    if currentNode == {}
+    if currentNode ==# {}
         call s:echo("Put the cursor on a file node first")
         return
     endif
@@ -3290,14 +3332,14 @@ function! s:deleteNode()
                          \ "==========================================================\n" .
                          \ "STOP! To delete this entire directory, type 'yes'\n" .
                          \ "" . currentNode.path.strForOS(0) . ": ")
-        let confirmed = choice == 'yes'
+        let confirmed = choice ==# 'yes'
     else
         echo "Delete the current node\n" .
            \ "==========================================================\n".
            \ "Are you sure you wish to delete the node:\n" .
            \ "" . currentNode.path.strForOS(0) . " (yN):"
         let choice = nr2char(getchar())
-        let confirmed = choice == 'y'
+        let confirmed = choice ==# 'y'
     endif
 
 
@@ -3310,7 +3352,7 @@ function! s:deleteNode()
             "close that buffer
             let bufnum = bufnr(currentNode.path.str(0))
             if buflisted(bufnum)
-                let prompt = "\nNode deleted.\n\nThe file is open in buffer ". bufnum . (bufwinnr(bufnum) == -1 ? " (hidden)" : "") .". Delete this buffer? (yN)"
+                let prompt = "\nNode deleted.\n\nThe file is open in buffer ". bufnum . (bufwinnr(bufnum) ==# -1 ? " (hidden)" : "") .". Delete this buffer? (yN)"
                 call s:promptToDelBuffer(bufnum, prompt)
             endif
 
@@ -3335,7 +3377,7 @@ endfunction
 " FUNCTION: s:executeNode() {{{2
 function! s:executeNode()
     let treenode = s:TreeFileNode.GetSelected()
-    if treenode == {} || treenode.path.isDirectory
+    if treenode ==# {} || treenode.path.isDirectory
         call s:echo("Select an executable file node first" )
     else
         echo "NERDTree executor\n" .
@@ -3355,7 +3397,7 @@ endfunction
 " FUNCTION: s:handleMiddleMouse() {{{2
 function! s:handleMiddleMouse()
     let curNode = s:TreeFileNode.GetSelected()
-    if curNode == {}
+    if curNode ==# {}
         call s:echo("Put the cursor on a node first" )
         return
     endif
@@ -3363,7 +3405,7 @@ function! s:handleMiddleMouse()
     if curNode.path.isDirectory
         call s:openExplorer()
     else
-        call s:openEntrySplit(0)
+        call s:openEntrySplit(0,0)
     endif
 endfunction
 
@@ -3372,7 +3414,7 @@ endfunction
 " Adds a new node to the filesystem and then into the tree
 function! s:insertNewNode()
     let curDirNode = s:TreeDirNode.GetSelected()
-    if curDirNode == {}
+    if curDirNode ==# {}
         call s:echo("Put the cursor on a node first" )
         return
     endif
@@ -3382,7 +3424,7 @@ function! s:insertNewNode()
                           \ "Enter the dir/file name to be created. Dirs end with a '/'\n" .
                           \ "", curDirNode.path.strForGlob() . s:os_slash)
 
-    if newNodeName == ''
+    if newNodeName ==# ''
         call s:echo("Node Creation Aborted.")
         return
     endif
@@ -3475,16 +3517,20 @@ function! s:openBookmark(name)
         call targetNode.open()
     endif
 endfunction
-" FUNCTION: s:openEntrySplit(forceKeepWindowOpen) {{{2
+" FUNCTION: s:openEntrySplit(vertical, forceKeepWindowOpen) {{{2
 "Opens the currently selected file from the explorer in a
 "new window
 "
 "args:
 "forceKeepWindowOpen - dont close the window even if NERDTreeQuitOnOpen is set
-function! s:openEntrySplit(forceKeepWindowOpen)
+function! s:openEntrySplit(vertical, forceKeepWindowOpen)
     let treenode = s:TreeFileNode.GetSelected()
     if treenode != {}
+        if a:vertical
+            call treenode.openVSplit()
+        else
             call treenode.openSplit()
+        endif
         if !a:forceKeepWindowOpen
             call s:closeTreeIfQuitOnOpen()
         endif
@@ -3538,7 +3584,7 @@ endfunction
 " FUNCTION: s:openNodeRecursively() {{{2
 function! s:openNodeRecursively()
     let treenode = s:TreeFileNode.GetSelected()
-    if treenode == {} || treenode.path.isDirectory == 0
+    if treenode ==# {} || treenode.path.isDirectory ==# 0
         call s:echo("Select a directory node first" )
     else
         call s:echo("Recursively opening node. Please wait...")
@@ -3551,10 +3597,13 @@ function! s:openNodeRecursively()
 endfunction
 
 "FUNCTION: s:previewNode() {{{2
+"Args:
+"   openNewWin: if 0, use the previous window, if 1 open in new split, if 2
+"               open in a vsplit
 function! s:previewNode(openNewWin)
     let currentBuf = bufnr("")
-    if a:openNewWin
+    if a:openNewWin > 0
-        call s:openEntrySplit(1)
+        call s:openEntrySplit(a:openNewWin ==# 2,1)
     else
         call s:activateNode(1)
     end
@@ -3586,7 +3635,7 @@ endfunction
 " refreshes the root for the current node
 function! s:refreshCurrent()
     let treenode = s:TreeDirNode.GetSelected()
-    if treenode == {}
+    if treenode ==# {}
         call s:echo("Refresh failed. Select a node first")
         return
     endif
@@ -3601,7 +3650,7 @@ endfunction
 " allows the user to rename the current node
 function! s:renameCurrent()
     let curNode = s:TreeFileNode.GetSelected()
-    if curNode == {}
+    if curNode ==# {}
         call s:echo("Put the cursor on a node first" )
         return
     endif
@@ -3611,7 +3660,7 @@ function! s:renameCurrent()
                           \ "Enter the new path for the node:                          \n" .
                           \ "", curNode.path.strForOS(0))
 
-    if newNodePath == ''
+    if newNodePath ==# ''
         call s:echo("Node Renaming Aborted.")
         return
     endif
@@ -3625,7 +3674,7 @@ function! s:renameCurrent()
         "if the node is open in a buffer, ask the user if they want to
         "close that buffer
         if bufnum != -1
-            let prompt = "\nNode renamed.\n\nThe old file is open in buffer ". bufnum . (bufwinnr(bufnum) == -1 ? " (hidden)" : "") .". Delete this buffer? (yN)"
+            let prompt = "\nNode renamed.\n\nThe old file is open in buffer ". bufnum . (bufwinnr(bufnum) ==# -1 ? " (hidden)" : "") .". Delete this buffer? (yN)"
             call s:promptToDelBuffer(bufnum, prompt)
         endif
 
@@ -3640,7 +3689,7 @@ endfunction
 " FUNCTION: s:showFileSystemMenu() {{{2
 function! s:showFileSystemMenu()
     let curNode = s:TreeFileNode.GetSelected()
-    if curNode == {}
+    if curNode ==# {}
         call s:echo("Put the cursor on a node first" )
         return
     endif
@@ -3717,7 +3766,7 @@ endfunction
 "re-rendered
 function! s:upDir(keepState)
     let cwd = b:NERDTreeRoot.path.str(0)
-    if cwd == "/" || cwd =~ '^[^/]..$'
+    if cwd ==# "/" || cwd =~ '^[^/]..$'
         call s:echo("already at top dir")
     else
         if !a:keepState
@@ -3734,7 +3783,10 @@ function! s:upDir(keepState)
             let b:NERDTreeRoot = newRoot
         else
             let b:NERDTreeRoot = b:NERDTreeRoot.parent
+        endif
 
+        if g:NERDTreeChDirMode ==# 2
+            exec 'cd ' . b:NERDTreeRoot.path.strForCd()
         endif
 
         call s:renderView()