vim: persistant undo

vim/vimrc

@@ -110,10 +110,15 @@ augroup LastPosition
         \ endif
 augroup END
 
-""" Persistent undo. Requires Vim 7.3 {{{
-if has('persistent_undo') && exists("&undodir")
-    set undodir=$HOME/.vim/undo/            " where to store undofiles
-    set undofile                            " enable undofile
+" Keep undo history across sessions by storing it in a file
+let vimDir = '$HOME/.vim'
+if has('persistent_undo')
+    let myUndoDir = expand(vimDir . '/undodir')
+    " Create dirs
+    call system('mkdir ' . vimDir)
+    call system('mkdir ' . myUndoDir)
+    let &undodir = myUndoDir
+    set undofile
     set undolevels=500                      " max undos stored
     set undoreload=10000                    " buffer stored undos
 endif