[vim] Don't start extra process when opening popup (#2000)

Fix #2038

plugin/fzf.vim

@@ -648,6 +648,7 @@ function! s:split(dict)
   \ 'left':  ['vertical topleft', 'vertical resize', &columns],
   \ 'right': ['vertical botright', 'vertical resize', &columns] }
   let ppos = s:getpos()
+  let is_popup = 0
   try
     if s:present(a:dict, 'window')
       if type(a:dict.window) == type({})
@@ -655,6 +656,7 @@ function! s:split(dict)
           throw 'Vim 8.2.191 or later is required for pop-up window'
         end
         call s:popup(a:dict.window)
+        let is_popup = 1
       else
         execute 'keepalt' a:dict.window
       endif
@@ -672,11 +674,11 @@ function! s:split(dict)
           endif
           execute cmd sz.'new'
           execute resz sz
-          return [ppos, {}]
+          return [ppos, {}, is_popup]
         endif
       endfor
     endif
-    return [ppos, { '&l:wfw': &l:wfw, '&l:wfh': &l:wfh }]
+    return [ppos, { '&l:wfw': &l:wfw, '&l:wfh': &l:wfh }, is_popup]
   finally
     setlocal winfixwidth winfixheight
   endtry
@@ -685,7 +687,7 @@ endfunction
 function! s:execute_term(dict, command, temps) abort
   let winrest = winrestcmd()
   let pbuf = bufnr('')
-  let [ppos, winopts] = s:split(a:dict)
+  let [ppos, winopts, is_popup] = s:split(a:dict)
   call s:use_sh()
   let b:fzf = a:dict
   let fzf = { 'buf': bufnr(''), 'pbuf': pbuf, 'ppos': ppos, 'dict': a:dict, 'temps': a:temps,
@@ -752,8 +754,17 @@ function! s:execute_term(dict, command, temps) abort
       if !len(&bufhidden)
         setlocal bufhidden=hide
       endif
-      let fzf.buf = term_start([&shell, &shellcmdflag, command], {'curwin': 1, 'exit_cb': function(fzf.on_exit)})
+      let term_opts = {'exit_cb': function(fzf.on_exit)}
-      if !has('patch-8.0.1261') && !has('nvim') && !s:is_win
+      if is_popup
+        let term_opts.hidden = 1
+      else
+        let term_opts.curwin = 1
+      endif
+      let fzf.buf = term_start([&shell, &shellcmdflag, command], term_opts)
+      if is_popup && exists('#TerminalWinOpen')
+        doautocmd <nomodeline> TerminalWinOpen
+      endif
+      if !has('patch-8.0.1261') && !s:is_win
         call term_wait(fzf.buf, 20)
       endif
     endif
@@ -824,23 +835,22 @@ if has('nvim')
 else
   function! s:create_popup(hl, opts) abort
     let is_frame = has_key(a:opts, 'border')
-    let buf = is_frame ? '' : term_start(&shell, #{hidden: 1, term_finish: 'close'})
+    let s:popup_create = {buf -> popup_create(buf, #{
-    let id = popup_create(buf, #{
       \ line: a:opts.row,
       \ col: a:opts.col,
       \ minwidth: a:opts.width,
       \ minheight: a:opts.height,
       \ zindex: 50 - is_frame,
-    \ })
+    \ })}
-
     if is_frame
+      let id = s:popup_create('')
       call setwinvar(id, '&wincolor', a:hl)
       call setbufline(winbufnr(id), 1, a:opts.border)
       execute 'autocmd BufWipeout * ++once call popup_close('..id..')'
+      return winbufnr(id)
     else
-      execute 'autocmd BufWipeout * ++once call term_sendkeys('..buf..', "exit\<CR>")'
+      autocmd TerminalOpen * ++once call s:popup_create(str2nr(expand('<abuf>')))
     endif
-    return winbufnr(id)
   endfunction
 endif