use g:unimpaired_prevnext

This is especially important for repeating [q/]q across buffers.

Author: blueyed

plugin/unimpaired.vim

@@ -61,15 +61,15 @@ call s:MapNextFamily('t','t')
 
 " Handle previous/next movements, storing the last used one.
 function! s:prevnext(cmd, dir, prevnext) abort
-  let b:unimpaired_prevnext = a:prevnext
+  let g:unimpaired_prevnext = a:prevnext
   let cmd = (v:count ? v:count : '').a:cmd.a:dir
   if a:cmd ==# 'l' || a:cmd ==# 'c'
     let cmd .= '|normal zv'
   endif
   return cmd
 endfunction
 function! s:last_prevnext_cmd(dir) abort
-  let prevnext = get(b:, 'unimpaired_prevnext', [])
+  let prevnext = get(g:, 'unimpaired_prevnext', [])
   if empty(prevnext)
     if &diff
       let m = 'c'