fix a bug where :NERDTreeToggle was broken without :set hidden

doc/NERD_tree.txt

@@ -949,6 +949,9 @@ fridge for later ;)
 ==============================================================================
 7. Changelog                                               *NERDTreeChangelog*
 
+3.0.1
+    - fix a bug where :NERDTreeToggle was broken unless 'hidden was set
+
 3.0.0
     - hijack netrw so that doing an :edit <directory>  will put a NERD tree in
       the window rather than a netrw browser. See :help 'NERDTreeHijackNetrw'

plugin/NERD_tree.vim

@@ -2931,6 +2931,9 @@ function! s:toggle(dir)
         if !s:isTreeOpen()
             call s:createTreeWin()
             call s:restoreScreenState()
+            if !&hidden
+                call s:renderView()
+            endif
         else
             call s:closeTree()
         endif