Refresh buffers after m, m operation on a folder (#888)

* WIP: Wow! That's an ugly diff. I'm not done yet, though.

* Fix the ugliness of the previous commit, and finish the work.

If the node being renamed is a directory, get a list of all open buffers
whose file lives in the old directory. If that list is not empty, ask
the user if he wants to replace the old buffers with the new files. The
logic to handle renaming a file node stays the same, although the code
has been refactored a bit.

nerdtree_plugin/fs_menu.vim

@@ -83,31 +83,32 @@ function! s:promptToDelBuffer(bufnum, msg)
     endif
 endfunction
 
-"FUNCTION: s:promptToRenameBuffer(bufnum, msg){{{1
-"prints out the given msg and, if the user responds by pushing 'y' then the
-"buffer with the given bufnum is replaced with a new one
+"FUNCTION: s:renameBuffer(bufNum, newNodeName, isDirectory){{{1
+"The buffer with the given bufNum is replaced with a new one
 "
 "Args:
-"bufnum: the buffer that may be deleted
-"msg: a message that will be echoed to the user asking them if they wish to
-"     del the buffer
-function! s:promptToRenameBuffer(bufnum, msg, newFileName)
-    echo a:msg
-    if g:NERDTreeAutoDeleteBuffer || nr2char(getchar()) ==# 'y'
-        let quotedFileName = fnameescape(a:newFileName)
-        " 1. ensure that a new buffer is loaded
-        exec "badd " . quotedFileName
-        " 2. ensure that all windows which display the just deleted filename
-        " display a buffer for a new filename.
-        let s:originalTabNumber = tabpagenr()
-        let s:originalWindowNumber = winnr()
-        let editStr = g:NERDTreePath.New(a:newFileName).str({'format': 'Edit'})
-        exec "tabdo windo if winbufnr(0) == " . a:bufnum . " | exec ':e! " . editStr . "' | endif"
-        exec "tabnext " . s:originalTabNumber
-        exec s:originalWindowNumber . "wincmd w"
-        " 3. We don't need a previous buffer anymore
-        exec "bwipeout! " . a:bufnum
+"bufNum: the buffer that may be deleted
+"newNodeName: the name given to the renamed node
+"isDirectory: determines how to do the create the new filenames
+function! s:renameBuffer(bufNum, newNodeName, isDirectory)
+    if a:isDirectory
+        let quotedFileName = fnameescape(a:newNodeName . '/' . fnamemodify(bufname(a:bufNum),':t'))
+        let editStr = g:NERDTreePath.New(a:newNodeName . '/' . fnamemodify(bufname(a:bufNum),':t')).str({'format': 'Edit'})
+    else
+        let quotedFileName = fnameescape(a:newNodeName)
+        let editStr = g:NERDTreePath.New(a:newNodeName).str({'format': 'Edit'})
     endif
+    " 1. ensure that a new buffer is loaded
+    exec "badd " . quotedFileName
+    " 2. ensure that all windows which display the just deleted filename
+    " display a buffer for a new filename.
+    let s:originalTabNumber = tabpagenr()
+    let s:originalWindowNumber = winnr()
+    exec "tabdo windo if winbufnr(0) == " . a:bufNum . " | exec ':e! " . editStr . "' | endif"
+    exec "tabnext " . s:originalTabNumber
+    exec s:originalWindowNumber . "wincmd w"
+    " 3. We don't need a previous buffer anymore
+    exec "bwipeout! " . a:bufNum
 endfunction
 "FUNCTION: NERDTreeAddNode(){{{1
 function! NERDTreeAddNode()
@@ -158,7 +159,11 @@ function! NERDTreeMoveNode()
     endif
 
     try
-        let bufnum = bufnr("^".curNode.path.str()."$")
+        if curNode.path.isDirectory
+            let l:openBuffers = filter(range(1,bufnr("$")),'bufexists(v:val) && fnamemodify(bufname(v:val),":p") =~# curNode.path.str() . "/.*"')
+        else
+            let l:openBuffers = filter(range(1,bufnr("$")),'bufexists(v:val) && fnamemodify(bufname(v:val),":p") ==# curNode.path.str()')
+        endif
 
         call curNode.rename(newNodePath)
         " Emptying g:NERDTreeOldSortOrder forces the sort to
@@ -167,11 +172,20 @@ function! NERDTreeMoveNode()
         call b:NERDTree.root.refresh()
         call NERDTreeRender()
 
-        "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)" : "") .". Replace this buffer with the new file? (yN)"
-            call s:promptToRenameBuffer(bufnum,  prompt, newNodePath)
+        " If the file node is open, or files under the directory node are
+        " open, ask the user if they want to replace the file(s) with the
+        " renamed files.
+        if !empty(l:openBuffers)
+            if curNode.path.isDirectory
+                echo "\nDirectory renamed.\n\nFiles with the old directory name are open in buffers " . join(l:openBuffers, ', ') . ". Replace these buffers with the new files? (yN)"
+            else
+                echo "\nFile renamed.\n\nThe old file is open in buffer " . l:openBuffers[0] . ". Replace this buffer with the new file? (yN)"
+            endif
+            if g:NERDTreeAutoDeleteBuffer || nr2char(getchar()) ==# 'y'
+                for bufNum in l:openBuffers
+                    call s:renameBuffer(bufNum, newNodePath, curNode.path.isDirectory)
+                endfor
+            endif
         endif
 
         call curNode.putCursorHere(1, 0)