Use stopline in highlight_surround (re #118)

autoload/matchup/delim.vim

@@ -174,6 +174,7 @@ function! matchup#delim#get_surrounding_impl(type, ...) " {{{1
   if get(l:opts, 'check_skip', 0)
     let l:delimopts.check_skip = 1
   endif
+  let l:delimopts.stopline = get(l:opts, 'stopline', s:stopline)
 
   " keep track of the outermost pair found so far
   " returned when g:matchup_delim_count_fail = 1

autoload/matchup/matchparen.vim

@@ -715,7 +715,7 @@ endfunction
 " }}}1
 
 function! s:highlight_surrounding(...) " {{{1
-  let l:opts = { 'local': 0, 'matches': [] }
+  let l:opts = {'local': 0, 'matches': [], 'stopline': 2*winheight(0)}
   let l:delims = matchup#delim#get_surrounding('delim_all', 1, l:opts)
   let l:open = l:delims[0]
   if empty(l:open) | return | endif