Save/Set screen state also on WinLeave and WinEnter. (#1048)

* Save/Set screen state also on WinLeave and WinEnter.

The particular use case here is when switching tabs with `gt` and the
NERDTrees have been mirrored.

* Update version number and change log.

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Change Log
 
+#### 6.1...
+- **.3**: Save/Set screen state also on WinLeave and WinEnter. (PhilRunninger) [#1048](https://github.com/scrooloose/nerdtree/pull/1048)
+- **.2**: Wrap saveScreenState's statements in a try-catch block. (PhilRunninger) [#1047](https://github.com/scrooloose/nerdtree/pull/1047)
+- **.1**: Catch errors when trying to read CHANGELOG.md. (PhilRunninger) [#1045](https://github.com/scrooloose/nerdtree/pull/1045)
+- **.0**: If file path doesn't exist, :NERDTreeFind its parent directory instead. (PhilRunninger) [#1043](https://github.com/scrooloose/nerdtree/pull/1043)
 #### 6.0...
 - **.1**: Reintroduce necessary variable mistakenly removed. (PhilRunninger) [#1040](https://github.com/scrooloose/nerdtree/pull/1040)
 - **.0**: Make the behavior of window splits consistent (dragonxlwang, PhilRunninger) [#1035](https://github.com/scrooloose/nerdtree/pull/1035)

autoload/nerdtree.vim

@@ -10,8 +10,9 @@ let s:rootNERDTreePath = resolve(expand("<sfile>:p:h:h"))
 "  change log is shown for the current version; otherwise, only the version
 "  number is shown.
 function! nerdtree#version(...)
-    let l:changelog = readfile(join([s:rootNERDTreePath, "CHANGELOG.md"], nerdtree#slash()))
     let l:text = 'Unknown'
+    try
+        let l:changelog = readfile(join([s:rootNERDTreePath, "CHANGELOG.md"], nerdtree#slash()))
         let l:line = 0
         while l:line <= len(l:changelog)
             if l:changelog[l:line] =~ '\d\+\.\d\+'
@@ -21,6 +22,8 @@ function! nerdtree#version(...)
             endif
             let l:line += 1
         endwhile
+    catch
+    endtry
     return l:text
 endfunction
 

autoload/nerdtree/ui_glue.vim

@@ -284,6 +284,9 @@ endfunction
 " FUNCTION: s:findAndRevealPath(pathStr) {{{1
 function! s:findAndRevealPath(pathStr)
     let l:pathStr = !empty(a:pathStr) ? a:pathStr : expand('%:p')
+    if !filereadable(l:pathStr)
+        let l:pathStr = fnamemodify(l:pathStr, ':h')
+    endif
 
     if empty(l:pathStr)
         call nerdtree#echoWarning('no file for the current buffer')

lib/nerdtree/ui.vim

@@ -355,12 +355,15 @@ endfunction
 " scroll position
 function! s:UI.saveScreenState()
     let win = winnr()
-    call g:NERDTree.CursorToTreeWin()
     let self._screenState = {}
+    try
+        call g:NERDTree.CursorToTreeWin()
         let self._screenState['oldPos'] = getpos(".")
         let self._screenState['oldTopLine'] = line("w0")
         let self._screenState['oldWindowSize']= winwidth("")
         call nerdtree#exec(win . "wincmd w", 1)
+    catch
+    endtry
 endfunction
 
 " FUNCTION: s:UI.setShowHidden(val) {{{1

plugin/NERD_tree.vim

@@ -170,10 +170,10 @@ call nerdtree#ui_glue#setupCommands()
 "============================================================
 augroup NERDTree
     "Save the cursor position whenever we close the nerd tree
-    exec "autocmd BufLeave ". g:NERDTreeCreator.BufNamePrefix() ."* if g:NERDTree.IsOpen() | call b:NERDTree.ui.saveScreenState() | endif"
+    exec "autocmd BufLeave,WinLeave ". g:NERDTreeCreator.BufNamePrefix() ."* if g:NERDTree.IsOpen() | call b:NERDTree.ui.saveScreenState() | endif"
 
     "disallow insert mode in the NERDTree
-    exec "autocmd BufEnter ". g:NERDTreeCreator.BufNamePrefix() ."* stopinsert"
+    exec "autocmd BufEnter,WinEnter ". g:NERDTreeCreator.BufNamePrefix() ."* stopinsert"
 augroup END
 
 if g:NERDTreeHijackNetrw