Bunch of changes inspired by r00k

vim/bundle/vim-obsession/plugin/obsession.vim

@@ -0,0 +1,71 @@
+" obsession.vim - Continuously updated session files
+" Maintainer:   Tim Pope <http://tpo.pe/>
+" Version:      1.0
+
+if exists("g:loaded_obsession") || v:version < 700 || &cp
+  finish
+endif
+let g:loaded_obsession = 1
+
+command! -bar -bang -complete=file -nargs=? Obsession execute s:dispatch(<bang>0, <q-args>)
+
+function! s:dispatch(bang, file) abort
+  if a:bang && empty(a:file) && filereadable(get(g:, 'this_obsession', v:this_session))
+    echo 'Deleting session in '.fnamemodify(get(g:, 'this_obsession', v:this_session), ':~:.')
+    call delete(get(g:, 'this_obsession', v:this_session))
+    unlet! g:this_obsession
+    return ''
+  elseif empty(a:file) && exists('g:this_obsession')
+    echo 'Pausing session in '.fnamemodify(g:this_obsession, ':~:.')
+    unlet g:this_obsession
+    return ''
+  elseif empty(a:file) && !empty(v:this_session)
+    let file = v:this_session
+  elseif empty(a:file)
+    let file = getcwd() . '/Session.vim'
+  elseif isdirectory(a:file)
+    let file = fnamemodify(expand(a:file), ':p') . '/Session.vim'
+  else
+    let file = fnamemodify(expand(a:file), ':p')
+  endif
+  if !a:bang
+     \ && file !~# 'Session\.vim$'
+     \ && filereadable(file)
+     \ && getfsize(file) > 0
+     \ && readfile(file, '', 1)[0] !=# 'let SessionLoad = 1'
+    return 'mksession '.fnameescape(file)
+  endif
+  let g:this_obsession = file
+  let error = s:persist()
+  if empty(error)
+    echo 'Tracking session in '.fnamemodify(file, ':~:.')
+    let v:this_session = file
+    return ''
+  else
+    return error
+  endif
+endfunction
+
+function! s:persist()
+  if exists('g:this_obsession')
+    let sessionoptions = &sessionoptions
+    try
+      set sessionoptions-=options
+      execute 'mksession! '.fnameescape(g:this_obsession)
+      call writefile(insert(readfile(g:this_obsession), 'let g:this_obsession = v:this_session', -2), g:this_obsession)
+    catch
+      unlet g:this_obsession
+      return 'echoerr '.string(v:exception)
+    finally
+      let &sessionoptions = sessionoptions
+    endtry
+  endif
+  return ''
+endfunction
+
+augroup obsession
+  autocmd!
+  autocmd BufEnter,VimLeavePre * exe s:persist()
+augroup END
+
+" vim:set et sw=2: