make the git menu own harder

ftplugin/nerdtree_git_menu.vim

@@ -10,12 +10,30 @@
 "              See http://sam.zoy.org/wtfpl/COPYING for more details.
 "
 " ============================================================================
+"
+" Adds a "g" submenu to the NERD tree menu.
+"
+" Note: this plugin assumes that the current tree root has a .git dir under
+" it, and that the working tree and the .git repo are in the same place
+"
 if exists("g:loaded_nerdtree_git_menu")
     finish
 endif
 let g:loaded_nerdtree_git_menu = 1
 
-call NERDTreeAddMenuItem('(g)it menu', 'g', 'NERDTreeGitMenu')
+call NERDTreeAddMenuItem({
+            \ 'text': '(g)it menu',
+            \ 'shortcut': 'g',
+            \ 'check_to_enable_callback': 'NERDTreeGitMenuEnabled',
+            \ 'callback': 'NERDTreeGitMenu' })
+
+function! NERDTreeGitMenuEnabled()
+    return isdirectory(s:GitRepoPath())
+endfunction
+
+function! s:GitRepoPath()
+    return b:NERDTreeRoot.path.str(0) . ".git"
+endfunction
 
 function! NERDTreeGitMenu()
     let node = g:NERDTreeFileNode.GetSelected()
@@ -36,26 +54,34 @@ function! NERDTreeGitMenu()
     let choice = nr2char(getchar())
 
     if choice ==# "a"
-        call s:promptCommand('git add ', path.strForOS(1), 'file')
+        call s:promptCommand('add ', path.strForOS(1), 'file')
     elseif choice ==# "c"
-        call s:promptCommand('git checkout ', path.strForOS(1), 'file')
+        call s:promptCommand('checkout ', path.strForOS(1), 'file')
     elseif choice ==# "m"
-        call s:promptCommand('git mv ', path.strForOS(1), 'file')
+        let p = path.strForOS(1)
+        call s:promptCommand('mv ', p . ' ' . p, 'file')
     elseif choice ==# "r"
-        call s:promptCommand('git rm ', path.strForOS(1), 'file')
+        call s:promptCommand('rm ', path.strForOS(1), 'file')
     endif
 
     call node.parent.refresh()
     call NERDTreeRender()
 endfunction
 
-function! s:promptCommand(cmd_base, cmd_tail_default, complete)
-    let cmd_tail = input(":!" . a:cmd_base,  a:cmd_tail_default, a:complete)
+function! s:promptCommand(sub_command, cmd_tail_default, complete)
+    let extra_options  = ' --git-dir=' . s:GitRepoPath()
+    let extra_options .= ' --work-tree=' . b:NERDTreeRoot.path.str(0) . ' '
+    let base = "git" . extra_options . a:sub_command
+
+    let cmd_tail = input(":!" . base,  a:cmd_tail_default, a:complete)
     if cmd_tail != ''
-        let output = system(a:cmd_base . cmd_tail)
+        let output = system(base . cmd_tail)
         redraw!
         if v:shell_error != 0
-            echom output
+            echo output
         endif
+    else
+        redraw
+        echo "Aborted"
     endif
 endfunction